• J. Wenninger
  CERN, Geneva

Beam commissioning of the LHC started with injection tests in August 2008, and a circulating beam was obtained in little over 3 days in September 2008. Unfortunately a powering incident in one the eight LHC sectors set an abrupt end to the beam commissioning in 2008. This talk will review the LHC beam commissioning achievements. It will describe the repair the LHC sector affected by the incident and present the measures that have been taken to avoid similar incidents in the future. The commissioning steps foreseen for the 2009 run and towards LHC design performance will be outlined.

Slides

• S. Krinsky
  BNL, Upton, Long Island, New York

Funding: This work was supported by Department of Energy contract DE-AC02-98CH10886.

The NSLS-II is an ultra-bright synchrotron light source based upon a storage ring with a 30-cell double-bend-achromat lattice with damping wigglers used to lower the emittance below 1 nm. In this talk we discuss the accelerator physics challenges for the design including: optimization of dynamic aperture; estimation of Touschek lifetime; achievement of required orbit stability; and analysis of ring impedance and collective effects.

Slides

• S.L. Kramer, A.K. Jain
  BNL, Upton, Long Island, New York

Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886

The NSLS-II light source is a proposed 3 GeV storage ring, with the potential for ultra-low emittance*. Despite the reduced emittance goal for the bare lattice, the closed orbit amplification factors are on average >50 in both planes, for random quadrupole alignment errors. The high chromaticity will also require strong sextupoles and the low 3 GeV energy will require large dynamic and momentum aperture to insure adequate lifetime. This will require tight alignment tolerances (~30microns) on the multipole magnets during installation. By specifying tight alignment tolerances of the magnets on the support girders, the random alignment tolerances of the girders in the tunnel can be significantly relaxed. Using beam based alignment to find the golden orbit through the quadrupole centers, the closed orbit offsets in the multipole magnets will then be reduced to essentially the alignment errors of the magnets, restoring much of the DA and lifetime of the bare lattice. Our R&D program to achieve these tight alignment tolerances of the magnets on the girders using a vibrating wire technique**, will be discussed and initial results presented.

*Work presented on behalf of the NSLS-II Design Team, CDR(2006) and CD2(2007).
**A. Jain, et al, International Workshop on Accelerator Alignment, Tsukuba, Japan, Feb.11-15, 2008.

• W. Meng, Y. Hao, A.K. Jain, V. Litvinenko, G.J. Mahler, J.E. Tuozzolo
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

eRHIC, a future high luminosity electron-ion collider at BNL, will add polarized electrons to the list of colliding species in RHIC. A 10-to-30 GeV electron energy recovery linac will require up to six passes around the RHIC 3.8 km circumference. We are developing and testing small (3-to-5 mm gap) dipole and quadrupole magnets and vacuum chambers for cost-effective eRHIC passes. We are also studying the sensitivity of eRHIC pass optics to magnet and alignment errors in such a small-magnet structure. We present the magnetic and mechanical designs of the small gap eRHIC components and prototyping test results.

• M. Okamura, J.M. Fite, V. Lo Destro, D. Raparia, J. Ritter
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

A steering magnet is not a major component in a beam line, however it is usually needed in any real set up. Also it is hard to estimate the required field strength before the beam line construction, since the strength needed is determined by misalignnment errors of other devises. Sometimes it is difficult to find enough space to install steering magnets because of other constraints on the length of the beamline. We compare two extreme designs of steering magnets. The first one is very thin steering magnet design which occupies only 6 mm in length and can be additionally installed as needed. The other is realized by applying extra coil windings to a quadrupole magnet and does not consume any length. We will present both designs in details and will discuss pros and cons.

• M. Rehak, J. Bengtsson, G. Danby, J.W. Jackson, J. Skaritka, C.J. Spataro
  BNL, Upton, Long Island, New York

Funding: US DOE Office of Basic Energy Sciences

Feasibility studies for two families of corrector magnets for NSLS-II are presented. The first family of magnets are generalizations of figure eight quadrupoles using rotationally symmetric breaks in the return yoke to fit in available space. Properties specific to figure eight magnet are identified. The second type of magnet is a combined sextupole/dipole trim.

• M. Rehak, A.K. Jain, J. Skaritka, C.J. Spataro
  BNL, Upton, Long Island, New York

Funding: US DOE Office of Basic Energy Sciences

The design and measurement of the NSLS-II ring quadrupoles prototypes are presented. These magnets are part of a larger prototype program described in [1]. Advances in software, hardware, and manufacturing have led to some new level of insight in the quest for the perfect magnet design. Three geometric features are used to minimize the first three allowed harmonics by way of optimization. Validations through measurement and confidence levels in calculations are established.

• J. Skaritka, J. Bengtsson, G. Danby, G. Ganetis, W. Guo, R.C. Gupta, J.W. Jackson, A.K. Jain, S.L. Kramer, S. Krinsky, Y. Li, W. Meng, B. Nash, S. Ozaki, M. Rehak, S. Sharma, C.J. Spataro, F.J. Willeke
  BNL, Upton, Long Island, New York

Funding: US DOE Office of Basic Energy Sciences

NSLS-II is a new state-of-the-art medium energy synchrotron light source designed to deliver world leading brightness and flux with top-off operation for constant output. Design and engineering of NSLS-II began in 2005 and the beginning of construction and operations are expected to start in 2009 and 2015, respectively. The energy of the machine is 3Gev and the circumference 792 m. The chosen lattice requires tight on magnetic field tolerances for the ring magnets. These magnets have been designed with 3D Opera software. The required multipole field quality and alignment preclude the use of multifunctional sextupoles, leading to discrete corrector magnets in the storage ring. The corrector magnets are multifunctional and will provide horizontal and vertical steering as well as skew quadrupole. This paper describes the dipoles, quadrupoles, sextupoles, and corrector magnets design and prototyping status of the NSLS-II.

• G. Danby, J.W. Jackson, A.K. Jain, M. Rehak, O. Singh, J. Skaritka, C.J. Spataro
  BNL, Upton, Long Island, New York

Funding: US DOE Office of Basic Energy Sciences

Discrete corrector magnets are used for the 230 horizontal and vertical steering magnets in the NSLS-II storage ring. A unique design incorporates both dipole and skew quad correctors for(DC) steering in the same magnet. Separate AC (orbit feedback) correctors have also been designed. Comparison with alternate designs are presented as well as prototype measurements

• S.M. Gurov, M.F. Blinov, A.E. Levichev, E.B. Levichev, P. Martyshkin, I.N. Okunev, V.V. Petrov, S.I. Ruvinsky, T.V. Rybitskaya, A.V. Semenov, A.V. Sukhanov, P. Vobly
  BINP SB RAS, Novosibirsk
• E. Boter, D. Einfeld, M. Pont
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

BINP has manufactured and measured 243 multipoles of 9 types for the ALBA storage ring. The magnets had severe requirements on the manufacturing tolerances and the alignment of their magnetic axes. The quadrupole magnets are made of 1mm laminated yokes with the bore diameter of 61mm. The sextupole magnets are made of 0.5mm laminated yokes with the bore diameter of 76mm. Rotating coils and Hall probes have been used for the magnetic measurements. The features of manufacturing and magnetic measurements are presented in this paper.

• H. Soltner, U. Bechstedt, R. Tölle
  FZJ, Jülich
• J.G. De Villiers
  iThemba LABS, Somerset West

Funding: Work supported by BMBF and NRF, Project code SUA 06/003

Forschungszentrum Jülich has taken the leadership of a consortium responsible for the design, installation and commissioning of the High-Energy Storage Ring (HESR) for antiprotons as part of the FAIR project at GSI in Darmstadt, Germany. Since a normal-conducting design of the ring has now been favored over the previously envisioned superconducting option, new calculations have been performed in order to assess the magnetic field characteristics of the normal-conducting dipole, quadrupole, and sextupole magnets of the HESR. This paper presents the physical features of the magnets and the results of the 3D calculations with emphasis on the various multipole contributions at the ends of the magnets.

• A. Peters, E. Feldmeier, R. Steiner
  HIT, Heidelberg
• H. Eickhoff, T. Knapp, C.P. Welsch
  GSI, Darmstadt
• C. Schömers
  MPI-K, Heidelberg

The use of hadron beams delivered by normal conducting synchrotrons is highly attractive in various fundamental research applications as well as in the field of particle therapy. These applications require fast synchrotron operation modes with pulse-to-pulse energy variation and magnetic field slopes up to 10 T/s. The aims are to optimize the duty-cycle or to minimize treatment times for the patients as well as to provide extremely stable properties of the extracted beams, i.e. position and spill structure. Studies performed at the SIS18 synchrotron at GSI showed that not only the dipoles but the quadrupoles as well significantly contribute to the underlying time constants of the slowly extracted beam. An attempt has been made to measure the magnetic fields in synchrotron magnets with high precision and speed comparable to the current measurement with a DCCT. Additional magnetic field monitoring includes the retarding effects into the current control feedback loop neglecting the unfavourable dynamic effects from hysteresis and eddy currents. The presentation describes this controls approach, the results obtained at the HIT synchrotron and the SIS18 at GSI will be discussed.

• M. Tawada, Y. Funakoshi, H. Koiso, N. Ohuchi, K. Oide, K. Tsuchiya
  KEK, Ibaraki

KEK is studying the design of the superconducting final focus quadrupoles for the Super KEKB. The system consists of quadrupole-doublet cooled at 1.9 K. The vertical focusing quadrupole has the maximum magnetic field more than 8 T in the superconducting coils. The field gradient at the magnet center is more than 80 T/m and the effective magnetic length is 0.25 m. The horizontal focusing quadrupole is designed with the field gradient of 9.5 T/m and the effective magnetic length of 1.0 m. These magnet parameters will be iterated in the process of optimizing the beam optics. In this paper, the conceptual design of final focusing system and magnets will be reported.

• Y. Iwashita, T. Sugimoto
  Kyoto ICR, Uji, Kyoto
• M. Masuzawa, T. Tauchi, K. Yokoya
  KEK, Ibaraki

Funding: Work partially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (A), 18204023(2006)

Although the base line technology of the Final Focus Doublet for ILC is superconducting magnet, which is supposed to be conventional, the slender structure may be suffered from its vibration. The permanent magnets, however, do not have any vibration source in it at the steady state. The five-ring-singlet configuration, proposed by R. L. Gluckstern adds 100% strength adjustability to permanent magnet quadrupole (PMQ) lens. A prototype of this lens is fabricated and under evaluation. It was originally designed for ILC that also has the extra hole for the outgoing beam. In order to realize the beam test at ATF2, the inner bore is enlarged from D20mm to D50mm to clear the background photons from Shintake-Monitor. The magnet is described.

• C.-S. Hwang, C.-H. Chang, H.-H. Chen, M.-H. Huang, J.C. Jan, C.Y. Kuo, F.-Y. Lin, C.-S. Yang
  NSRRC, Hsinchu

The accelerator lattice magnets of the Taiwan Photon Source (TPS) with energy 3 GeV have been designed for the storage and booster ring. The magnetic computation codes of TOSCA and RADIA software packages were used to design the magnet circuits of the accelerator magnets. Meanwhile, the design of a magnet circuit must take into account both the requirements of accelerator physics and practical engineering constraints. The criterion of magnet design is to keep a rise of coil temperature within 10o C and a safety margin greater than 15 %. We apply pole edge shims and end magnet chamfers to enhance the field homogeneity and to decrease multipole components, respectively. The edge shim involves a smaller magnet dimension but maintains the same quality of the field. Use of an end magnet chamfer avoids field saturation. The mechanical engineering design of the storage ring magnets has been completed and the booster ring magnets have started to be designed. The 3D Solidworks package was used to draw and design the mechanical engineering. The prototype magnets of the storage ring have been contracted out to the local company in Taiwan and will be finished before the end of 2009.

• J.C. Jan, C.-H. Chang, C.-S. Hwang, F.-Y. Lin
  NSRRC, Hsinchu

Lots of multipole magnets will be fabricated for the accelerator lattice magnets of Taiwan Photon Source (TPS) that include the storage ring magnets, booster ring magnets, and the transfer line magnets. Therefore, several precise rotating-coil measurement systems (RCS) with high speed measurement are developed to characterize the magnetic field of quadrupole (QM) and sextupole (SM) magnets. Printed circuit coil including normal-coil and bucking-coil, are applied to measure the absolute and relative values of multipole components, respectively. Normal-coils with three turns (single-layer-coil) has been previously discussed and found to have good reproducibility. Moreover, a 12-turn multi-layer-coil has been designed to characterize the booster ring multipole magnets of TPS. This study, compares the compensatory characteristics of two bucking-coils with 75/150 turns and 150/300 turns with those of normal-coil. A continuously-winding-method for bucking-coil is presented in the paper. A precision testing bench was used to test the performance of this system. This work describes the measurement system design and fabrication, and discusses the system precision and accuracy.

• C.Y. Kuo, C.-H. Chang, C.-S. Hwang
  NSRRC, Hsinchu

Bending magnets, quadrupole magnets, and sextupole magnets are the most crucial magnetic elements in the synchrotron accelerator facility or high energy accelerator collider ring. Generally, separate bending magnets, quadrupoles or sextupoles magnets are utilized to perform separate functions. However, in the lattice design of accelerator ring or a compact ring in limited space, a single multifunction magnet is used to reduce the number of magnets and ensure that the entire device fits into the available space. This work presents an approach for designing the pole profiles of a combined-function bending magnet of the dipole, quadrupole, and sextupole components. The pole profile of a combined quadrupole magnet with gradient field and sextupole field components is also discussed.

• J. G. Wang
  ORNL, Oak Ridge, Tennessee

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

3D computer simulations are performed to study magnetic field qualities in the SNS ring extraction Lambertson septum magnet. This work is motivated by the existence of a significant skew quad term in the magnet that has been identified as the source of causing a beam profile distortion on the target. The skew quad term is computed with different methods in simulations and is compared to measurement data. The origin of the large skew quad term is thoroughly investigated. The remedy for minimizing the skew quad term by modifying the magnet is also proposed. Particle tracking has been performed to verify the beam profile evolution through the existing and modified septum. The magnetic interference to the septum performance from an adjacent quadrupole is also assessed. This paper reports our simulation techniques and major results.

• D.E. Kim, H.S. Han, H.-G. Lee, K.-H. Park, H.S. Suh, Y.G. Young-Gyu
  PAL, Pohang, Kyungbuk

Funding: Supported by the MOEST of Korea and by POSCO

Pohang Accelerator Laboratory (PAL) is planning to upgrade the Pohang Light Source (PLS) which is a 3rd generation light source operating since 1995. The key features of the upgrade are, decrease of the beam emittance to 5.6 nm, increasing the beam energy to 3.0 GeV, additional shorter straight sections for more insertion devices. Because the PLSII should use practically same circumference preserving the shielding wall structure of the existing PLS, the lattice space is squeezed to the limit to secure the additional space for the insertion devices. This requirements forces heavy use of the combined function magnet. All dipoles are replaced to gradient magnet, and all sextupoles have horizontal corrector winding, vertical corrector winding, skew quadrupole windings. In this report, the design features and engineering efforts for the PLSII magnet systems are reported.

• T. Hiatt, K.S. Baggett, J.M. Beck, J.G. Dail, L. Harwood, J. Meyers, M. Wiseman
  JLAB, Newport News, Virginia

Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) currently has maximum beam energy of 6 GeV. The 12 GeV Upgrade Project will double the existing energy and is currently scheduled for completion in 2014. This doubling of energy requires modifications to the beam transport system which includes the addition of several new magnet designs and modifications to many existing designs. Prototyping efforts have been concluded for two different designs of quadrupole magnets required for the upgrade. The design, fabrication and measurement will be discussed.

Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.

• X. Zhao, G. Feng, W. Li, L. Wang, H. Xu, S.C. Zhang
  USTC/NSRL, Hefei, Anhui

HALS(Hefei Advanced Light Source) is the electron storage ring of ultra-low emittance in process of design. Under this design, the quadrupole magnet with sextupole component must be mounted on which the βη is much bigger, to use enough the effect of compersation chromaticity of sextupole magnet field and to use sparingly the space in the same time . So the combined quadrupole and sextupole magnet must be designed, and have more strong sextupole component and restrain the production of high harmonic field. In this paper, the chocie of design scheme is discussed, and the calculation of combined quadrupole and sextupole mangnet design is given.

• R.B. Meinke, J. Lammers, P.J. Masson, G.M. Stelzer
  AML, Palm Bay, Florida

Magnets for beam steering, focusing and optical corrections often have demanding requirements on field strength, field uniformity, mechanical robustness and high radiation strength. The achievable field strength in normal conducting magnets is limited by resistive heating of the conductor. A break-through magnet technology, called “Direct Double-HelixTM” allows operation at current densities in excess of 100 A/mm2 with conventional water cooling. The conductive path generating the magnetic field is machined out of conductive cylinders, which are arranged as concentric structures. Geometrical constraints of conventional conductors, based on wire manufacturing, are eliminated. The coolant, typically water or air, is in direct contact with the conductor and yields very high cooling efficiency. Based on Double-HelixTM technology the conductor path is optimized for high field uniformity for accelerator magnets with arbitrary multipole order or combined function magnets. Advanced machining technologies, enable unprecedented magnet miniaturization. These magnets can operate at temperatures of several hundred degrees Celsius and can sustain high radiation levels.

• B. Parker, M. Anerella, J. Escallier, P. He, A.K. Jain, A. Marone
  BNL, Upton, Long Island, New York
• B. Bolzon, A. Jeremie
  IN2P3-LAPP, Annecy-le-Vieux
• P.A. Coe, D. Urner
  OXFORDphysics, Oxford, Oxon
• C. Hauviller
  CERN, Geneva
• A. Seryi
  SLAC, Menlo Park, California
• T. Tauchi, K. Tsuchiya, J. Urakawa
  KEK, Ibaraki

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

The Accelerator Test Facility (ATF2) at KEK is a scaled down version of the final focus design proposed for the future linear colliders (LC) and aims to experimentally verify the final focus (FF) technology needed to obtain very small, stable beam spots at a LC interaction point. Initially the ATF2 FF is made using conventional (warm) quadrupole and sextupole magnets; however, we propose to upgrade the FF by replacing some of the conventional magnets with new superconducting magnets constructed with the same technology as those of the International Linear Collider baseline FF magnets*. With the superconducting magnet upgrade we can look to achieve smaller interaction point beta-functions and to study superconducting magnet vibration stability in an accelerator environment. Therefore for the ATF2 R&D magnet we endeavor to incorporate cryostat design features that facilitate monitoring of the cold mass movement via interferometric techniques. The design status of the ATF2 superconducting upgrade magnets is reported in this paper.

*International Linear Collider Reference Design Report, ILC-REPORT-2007-001, August 2007.

• E. Paoloni
  University of Pisa and INFN, Pisa
• S. Bettoni
  CERN, Geneva
• M.E. Biagini, P. Raimondi
  INFN/LNF, Frascati (Roma)
• M.K. Sullivan
  SLAC, Menlo Park, California

We present an improved design of the focusing elements close to the interaction point of the SuperB accelerator. These magnets have to provide pure quadrupolar fields on each of the two beams to decrease the background rate in the detector which would be produced by the over-bend of the off-energy particles if a dipolar component were present. Very good field quality is also required to preserve the dynamic aperture of the rings. Because of the small separation of the two beams (only few centimeters) and the high gradient required by the SuperB final focus, neither a permanent magnet design nor a multi-layer configuration are viable solutions. A novel design, based on 'helical-type' windings, has therefore been investigated. In this paper we will present the improved magnetic design and its performances evaluated with a three dimensional finite element analysis.

• L. Bottura, M.C.L. Buzio, N. Catalan-Lasheras, L. Deniau, M. DiCastro, S.D. Fartoukh, M. Giovannozzi, P. Hagen, J.-P. Koutchouk, M. Lamont, J. Miles, RV. Remondino, N.J. Sammut, S. Sanfilippo, F. Schmidt, D. Sernelius, R.J. Steinhagen, M. Strzelczyk, E. Todesco, R. Tomás, W. Venturini Delsolaro, L. Walckiers, J. Wenninger, R. Wolf, P. Xydi
  CERN, Geneva

The start-up of the LHC has provided the first field test for the concept, functionality and accuracy of FiDeL, the Field Description for the LHC. FiDeL is primarily a parametric model of the transfer function of the main field integrals generated by the series of magnets in the LHC powering circuits, from main optical elements to high-order harmonic correctors, both superconducting and normal-conducting magnets. In addition, the same framework is used to predict harmonic errors of both static and dynamic nature, and forecast appropriate corrections. In this paper we give a description of the level of detail achieved in the model and the rationale adopted for the LHC start-up. Beam-based measurements have been used for an assessment of the first-shot accuracy in the prediction of the current setting for the main arc magnets*.

*The work reported has been performed by the authors and the FiDeL Team

• R. Denz, K. Dahlerup-Petersen, F. Formenti, K.H. Meß, A.P. Siemko, J. Steckert, L. Walckiers
  CERN, Geneva
• J. Strait
  Fermilab, Batavia

Prior to the re-start of the Large Hadron Collider LHC in 2009 the protection system for superconducting magnets and bus bars QPS will be submitted to a substantial upgrade. The foreseen modifications will enhance the capability of the system in detecting problems related to the electrical interconnections between superconducting magnets as well as the detection of so-called symmetric quenches in the LHC main magnets. The paper will describe the design and implementation of the new protection layers and report as well on the commissioning of the system and first operational results.

• J. Strait
  Fermilab, Batavia
• R. Bailey, M. Bednarek, B. Bellesia, N. Catalan-Lasheras, K. Dahlerup-Petersen, R. Denz, C. Fernandez-Robles, R.H. Flora, E. Gornicki, M. Koratzinos, M. Pojer, L. Ponce, R.I. Saban, R. Schmidt, A.P. Siemko, M. Solfaroli Camillocci, H. Thiesen, A. Vergara-Fernández
  CERN, Geneva
• Z. Charifoulline
  RAS/INR, Moscow
• P. Jurkiewicz, P.J. Kapusta
  HNINP, Kraków

The incident of 19 September 2008 at the LHC was apparently caused by a faulty inter-magnet splice of about 200 nOhm resistance. Cryogenic and electrical techniques have been developed to detect other abnormal splices, either between or inside the magnets. The quench protection system is used in a special mode to measure the voltage across each magnet with an accuracy better than 0.1 mV, allowing internal splices with R > 10 nOhm to be detected. Since this system does not cover the bus between magnets, the cryogenic system is used in a special configuration* to measure the rate of temperature rise due to ohmic heating. Accuracy of a few mK/h, corresponding to a few Watts, has been achieved. This allows detection of excess resistance of more than a few tens of nOhms in a cryogenic sub-sector (2 optical cells). Follow-up measurements, using an ad-hoc system of high-accuracy voltmeters, are made in regions identified by the cryogenic system. These techniques have detected two abnormal internal magnet splices of 100 nOhms and 50 nOhms respectively. In 2009, this ad-hoc system will be replaced with a permanent one which will monitor all splices at the nOhm level.

*L. Tavian, Helium II Calorimetry for the Detection of Abnormal Resistive Zones in LHC Sectors, this conference.

• M.J. Lamm, N. Andreev, V. Kashikhin, V.S. Kashikhin, A.V. Makarov, M.A. Tartaglia, K. Yonehara, M. Yu, A.V. Zlobin
  Fermilab, Batavia
• R.P. Johnson, S.A. Kahn
  Muons, Inc, Batavia

Funding: Supported in part by USDOE STTR Grant DE-FG02-06ER86282

Magnets for the proposed muon cooling demonstration experiment MANX (Muon collider And Neutrino factory eXperiment) have to generate longitudinal solenoid and transverse helical dipole and helical quadrupole fields. This paper discusses the 0.4 M diameter 4-coil Helical Solenoid (HS) model design, manufacturing, and testing that has been done to verify the design concept, fabrication technology, and the magnet system performance. The model quench performance in the FNAL Vertical Magnet Test Facility (VMTF) will be discussed.

• K. Yonehara, V.S. Kashikhin, M.J. Lamm, M.L. Lopes, A.V. Zlobin
  Fermilab, Batavia
• R.P. Johnson, S.A. Kahn, M.L. Neubauer
  Muons, Inc, Batavia

Funding: Supported in part by USDOE STTR Grant DE-FG02-07ER84825 and by FRA under DOE Contract DE-AC02-07CH11359

The helical cooling channel is proposed to make a quick muon beam phase space cooling in a short channel length. The challenging part of the helical cooling channel magnet design is how to integrate the RF cavity into the compact helical cooling magnet. This report shows the possibility of the integration of the system.

• S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, P. Ferracin, R.R. Hafalia, R. Hannaford, G.L. Sabbi
  LBNL, Berkeley, California
• G. Ambrosio, R. Bossert, V. Kashikhin, D. Pasholk, A.V. Zlobin
  Fermilab, Batavia
• M. Anerella, A.K. Ghosh, J. Schmalzle, P. Wanderer
  BNL, Upton, Long Island, New York

Funding: This work was supported in part by the Director, Office of Science, High Energy Physics, U.S. Department of Energy under contract No. DE-AC02-05CH11231

Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Large Hadron Collider (LHC) at CERN. Nb3Sn conductor is at the present time the only practical superconductor capable of generating fields beyond 10 T. In support of the LHC Phase-II upgrade, the US LHC Accelerator Research Program (LARP) is developing a large bore (120mm) IR quadrupole (HQ) capable of reaching 15 T at its conductor peak field. The 1 m long two-layer coil, based on the design of the LARP TQ quadrupole series that achieved 230 T/m in a 90 mm bore, will demonstrate additional features such as alignment and accelerator field quality while exploring the magnet performance limits in terms of gradient, forces and stresses. In this paper we summarize the design and report on the magnet construction progress.

• X. Wang, S. Caspi, D.W. Cheng, H. Felice, P. Ferracin, R.R. Hafalia, J.M. Joseph, A.F. Lietzke, J. Lizarazo, A.D. McInturff, G.L. Sabbi
  LBNL, Berkeley, California
• K. Sasaki
  KEK, Ibaraki

Funding: U.S. Department of Energy

The Superconducting Magnet Program at Lawrence Berkeley National Laboratory has designed and tested HD2, a 1 m long Nb3Sn accelerator-type dipole with a 42 mm clear bore. HD2 is based on a simple block-type coil geometry with flared ends, and represents a step towards the development of cost-effective accelerator quality magnets operating in the range of 13-15 T. The design was optimized to minimize geometric harmonics and to address iron saturation and conductor magnetization effects. Field quality was measured during recent cold tests. The measured harmonics are presented and compared to the design values.

• Z.R. Wolf, S.D. Anderson, V. Kaplounenko, Yu.I. Levashov, A.W. Weidemann
  SLAC, Menlo Park, California

The LCLS project at SLAC requires 40 undulators be tuned, fiducialized, and a final data set taken. The techniques used to do this work are presented. In addition, the quadrupoles between the undulators must be accurately fiducialized. A description of the quadrupole magnetic measurements and fiducialization is also presented.

• C. Garion, H. Kos
  CERN, Geneva

The Compact LInear Collider, under study, requires vacuum chambers with a very small aperture, of the order of 8 mm in diameter, and with a length up to around 2 m for the main beam quadrupoles. To keep the very tight geometrical tolerances on the quadrupoles, no bake out is allowed. The main issue is to reach UHV conditions (typically 10^-9 mbar static pressure) in a system where the vacuum performance is driven by water outgassing. For this application, a thin-walled stainless steel vacuum chamber with two ante chambers equipped with NEG strips, is proposed. The mechanical design, especially the stability analysis, is shown. The key technologies of the prototype fabrication are given. Vacuum tests have been carried out on the prototypes. The test set-up as well as the performance of the pumping system are presented and compared with predictions.

• M.C. Bellachioma, H. Kollmus, A. Krämer, J. Kurdal, H. Reich-Sprenger
  GSI, Darmstadt
• M. Bender
  LMU, München

Funding: EU design study, contract 515876, DIRAC-PHASE-1, RP6 SIS 18-2

For the future FAIR facility intensities up to 10¹² U²⁸⁺ ions per second are required. For this purpose the existing heavy ion synchrotron SIS18, which will serve as injector, has to be upgraded. Since the required base pressure is 10^-10 Pa, among the different measures undertaken to improve the existing UHV system, the installation of NEG coated magnet chambers is foreseen. Two magnetron sputtering facilities were designed and commissioned at GSI to perform the coating. The characterization of the thin films has been carried out by RBS and XPS. Considering that the vacuum chambers mounted in accelerators undergo several venting-activation cycles, a deep investigation on the NEG aging was performed by ERDA. Fourteen dipole and one quadrupole chambers were coated and installed in the SIS 18, and the replacement of the remaining magnet pipes will follow in the next years. Additionally to overcome the dynamic vacuum instability a collimation system equipped with thin film coated absorbers was successfully tested in 2008. The coating facilities, their operating mode, the results achieved on the thin film characterization, and the ones obtained in the SIS 18 are presented.

• D. Raparia, J.G. Alessi, B. Briscoe, J.M. Fite, O. Gould, A. Kponou, V. Lo Destro, M. Okamura, J. Ritter, A. Zelenski
  BNL, Upton, Long Island, New York

The low energy (35 keV) and medium energy (750 keV) transport lines for (un)polarized H^- have been reconfigured to reduce beam losses and the beam emittance out of the 200 MeV Linac. The medium energy line in the original layout was 7 m long, and had ten quadrupoles, two beam choppers, and three bunchers. The bunchers were necessary to keep the beam bunched at the entrance of the Linac. About 35% beam loss occurred, and the emittance growth was several fold. In the new layout, the 750 keV line is only 0.7 m long, with three quads and one buncher. To preserve beam polarization in the 35 keV line, the solenoid in front of the RFQ (35 keV to 750 keV) was replaced with an Einzel lens. To reduce the spin-precession in the LEBT, which may cause the depolarization, a 47.4 degree bend was removed and focusing solenoid in front of RFQ was replaced with an Einzel lens. We will present the experimental result of the upgrade.

• M.O.A. El Ghazaly
  KUK, Abha
• M.H. Al-Malki, M.O.A. El Ghazaly
  KACST, Riyadh
• A.I. Papash
  MPI-K, Heidelberg
• C.P. Welsch
  Cockcroft Institute, Warrington, Cheshire

At the National Centre for Mathematics and Physics (NCMP), at the King Abdulaziz City for Science and Technology (KACST), Saudi Arabia, a multi-purpose low-energy experimental platform is presently being developed in collaboration with the QUASAR group. The aim of this project is to enable a multitude of low-energy experiments with most different kinds of ions both in single pass setups, but also with ions stored in a low-energy electrostatic storage ring. In this contribution, the injector of this complex is presented. It was designed to provide beams with energies of up to 30 kV/q and will allow for switching between different ion sources from e.g. duoplasmatron to electrospray ion sources and to thus provide the users with a wide range of different beams. We present the overall layout of the injector with a focus on its mechanical and ion optical design.

• A. Cianchi
  Università di Roma II Tor Vergata, Roma
• D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, M. Ferrario, D. Filippetto, G. Gatti, E. Pace, C. Vaccarezza, C. Vicario
  INFN/LNF, Frascati (Roma)
• L. Ficcadenti, A. Mostacci
  Rome University La Sapienza, Roma
• B. Marchetti
  INFN-Roma II, Roma
• C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)

The SPARC photoinjector drives a SASE FEL to perform several experiments both for the production of high brightness electron beam and for testing new scheme of SASE radiation generation. The control of the beam properties, in particular at the level of the slice dimension, is crucial in order to optimize the FEL process. We report the different measurements performed in order to characterize the slice properties of the electron beam.

• R.C. Gupta, A.K. Jain
  BNL, Upton, Long Island, New York

Funding: US DOE Office of Basic Energy Sciences

This paper will describe the requirements, the design and the prototype test results of the magnets for the new synchrotron radiation source NSLS-II now under construction at BNL. Several innovations have been incorporated in the design, in manufacturing and in the alignment procedures of the magnets. Prototypes of these magnets have been built in industry. A dipole design has been developed with a maximized magnetic length which is longer than the mechanical length. The quadrupole and sextupole magnets of NSLS-II must be aligned and positioned to better than 30 microns, a level never achieved before in such accelerators. The paper will present a brief status of the progress made in the techniques developed to measure and achieve these demanding requirements. Another concern has been the distortion of field quality due to the small (150 mm) axial spacing between the iron-yoke of two adjacent magnets. Calculations (in 3-D) and the result of systematic measurements of the field quality in the presence of other magnets and other machine components in close proximity will be presented.

Slides

• N. Marks
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

The latest initiatives to design and build non-scaling FFAGs have encountered novel technical challenges; the required DC combined function magnets (normal and superconducting) and fast pulsed magnets for injection and extraction present new problems. The talk will report on progress in meeting these challenges for the non-scaling machines, EMMA and PAMELA and will provide details of their current design status. With the main EMMA ring magnets now being delivered and the injection and extraction magnets being assembled in-house, practical engineering features of these systems will be presented.

Slides

• L. Rossi, V. Parma
  CERN, Geneva

The LHC magnet system has been largely commissioned in 2007-08: all sectors up to 7 kA (4 TeV proton beam energy); six (out of eight) sectors were commissioned up 9.3 kA (5.5 TeV) and one to 11.5 kA (6.9 TeV). For more than one week, both beams have been injected, circulated and captured in the RF bucket, thus assessing the optics at injection energy. The incident in sector 3-4, originated by a serious defect of a high-current joint between magnets with large collateral damage, has changed the plans: magnets in the damaged zone (about 50) are being substituted or repaired meanwhile a campaign of consolidation is under way. During commissioning, the training of the main dipoles was longer than expected on the basis of reception tests of individual magnets , thus pointing to a partial loss of quench memory. The thermal performance is within heat losses estimates and the spectacular easiness of the first injection test on 10th September has demonstrated the very good field quality, precise understanding of magnetic characteristics, quality of the elaborate field modeling and the very good shape of the magnets with proper alignment of the machine.

Slides

• G.L. Sabbi
  LBNL, Berkeley, California

Funding: Supported by the U.S.Department of Energy under Contract No. DE-AC02-05CH11231.

Insertion quadrupoles with large aperture and high gradient are required to achieve the luminosity upgrade goal of 10³⁵ cm^-2 s^-1 at the Large Hadron Collider (LHC). In 2004, the US Department of Energy established the LHC Accelerator Research Program (LARP) to develop a technology base for the upgrade. The focus of the magnet program, which is a collaboration of three US laboratories, BNL, FNAL and LBNL, is on development of high gradient quadrupoles using Nb3Sn in order to operate at high field and with sufficient temperature margin. Program components address technology issues regarding coil and structure fabrication, quench performance, field quality and alignment, length scale-up, quench protection, radiation hardness, conductor and cable. This paper reports the current status of model quadrupole development and outlines the long-term goals of the program.

Slides

• Y. Senichev
  FZJ, Jülich

A possible solution to avoid the transition energy crossing is the lattice with a negative momentum compaction factor. The developed lattice is based on the resonantly correlated curvature and gradient modulations in arcs with integer tunes in horizontal or both planes, and it called the “resonant” lattice*. This method was adopted for the TRIUMF and Moscow Kaon Factories. It was then applied in the SSC Low Energy Booster, the CERN Neutrino Factory, and in the Main Ring of the Japan Proton Accelerator Research Complex facility. For the superconducting option of High Energy Storage Ring lattice of the FAIR project, the same idea was also accepted, and at last it is one of the candidates for PS2 in CERN as well. Due to special features the idea of “resonant” lattice can be applied for the lattice with the stochastic cooling where the different arcs have the different mixing factors with conservation of the dynamic aperture for whole machine. The “resonant” lattice is appeared to be useful for electron machines where the minimum momentum-compaction factor and the minimum modulation of the dispersion function are both required simultaneously to have a small horizontal emittance.

*Yu. Senichev and A. Chechenin, Journal of Experimental and Theoretical Physics, 2007, v. {10}5, No. 6, p. 1141

Slides

• M.P. Anania, D. Clark, R.C. Issac, D.A. Jaroszynski, A. J. W. Reitsma, G.H. Welsh, S.M. Wiggins
  USTRAT/SUPA, Glasgow
• J.A. Clarke, M.W. Poole, B.J.A. Shepherd
  Cockcroft Institute, Warrington, Cheshire
• M.J. de Loos, S.B. van der Geer
  Pulsar Physics, Eindhoven

Funding: The U.K. EPSRC and the European Community - New and Emerging Science and Technology Activity under the FP6 “Structuring the European Research Area” programme (project EuroLEAP, contract number 028514)

The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme* is developing laser-plasma accelerators for the production of ultra-short electron bunches as drivers of incoherent and coherent radiation sources from plasma and magnetic undulators. Focusing of ultra-short electron bunches from a laser-plasma wakefield accelerator into an undulator requires that particular attention be paid to the electron beam quality. We will discuss the design and implementation of an upgraded focusing system for the ALPHA-X beam line, which currently consists of a triplet of electromagnet quadrupoles. The upgrade will comprise the installation of additional compact permanent quadrupoles** very close to the accelerator exit. This will improve the matching of the beam into the undulator. The design has been carried out using the General Particle Tracer (GPT) code*** and TRANSPORT code, which consider space charge effects and allow a realistic estimate of electron beam properties inside the undulator to be obtained. We will present a study of the influence of beam transport on free-electron laser action in the undulator, paying particular attention to bunch dispersion.

* D. Jaroszynski et al., Phil. Trans. R. Soc. A 364, 689-710 (2006)
** T. Eichner et al., Phys. Rev. ST Accel. Beams 10, 082401 (2007)
*** S.B. Geer, M.J. Loos, Ph.D. thesis, TU/e, Eindhoven (2001)

Slides

• W. Wan
  LBNL, Berkeley, California

Electron microscopes and streak cameras are "mini accelerators". Advanced techniques in electron optics have been successfully applied to the design and optimization of electron microscopes and streak cameras. This talk is an overview of the status and unique designs that have arisen, with emphasis on the theoretical aspects.

Slides

• J. Feikes, M.V. Hartrott, G. Wüstefeld
  BESSY GmbH, Berlin
• A. Hoehl, R. Klein, C. Koschitzki, G. Ulm
  PTB, Berlin

Funding: Work funded by Physikalisch-Technische Bundesanstalt

The Metrology Light Source (MLS) [1] is in user operation since 2008 at operating energies ranging from 10⁵ MeV up to 630 MeV and with multi bunch currents up to 200 mA. At the injection energy of 10⁵ MeV as soon as the beam current exceeds a few mA, the beam is strongly blown up in all three spatial dimensions and strong oscillations at very different spectral frequencies can be observed. These effects are caused by the interaction of beam charge with ions present and their strength and characteristic time scales depend on several machine parameters. As ion effects can strongly deteriorate the performance of the MLS, we report on first investigations.

• G. Wüstefeld, J. Feikes, M.V. Hartrott
  BESSY GmbH, Berlin
• A. Hoehl, R. Klein, R. Müller, G. Ulm
  PTB, Berlin

The Metrology Light Source (MLS)* is in user operation since April 1st, 2008. It is the first storage ring designed and built for operation in the low α mode, which relies on the control of higher order terms of the momentum compaction factor α with respect to the momentum deviation dp/p, α=a₀+a₁*dp/p+a₂*(dp/p)**2. The a₀ term is controlled by quadrupoles, a₁ by 3 families of sextupoles for controlling the chromaticity in the transverse and longitudinal planes, the a₂ term is controlled by an octupole family. The a₀ value can be varied by more than a factor of {10}00. The low α mode is also called 'isochronous' operation, it is used for short bunch operation, where intense signals of coherent sub-THz radiation are produced. We report on operation experience of this scheme.

*R. Klein et al., 'Operation of the Metrology Light Source as a primary radiation source standard',
PHYSICAL REVIEW SPECIAL TOPICS - ACCELERATORS AND BEAMS 11, 110701 (2008).

• W. Guo, S.L. Kramer, S. Krinsky, Y. Li, B. Nash, T. Tanabe
  BNL, Upton, Long Island, New York

Funding: NSLS-II, Brookhaven National Laboratory

NSLS-II, the third-generation light source which will be built at BNL is designed and optimized for 3 GeV energy, ultra-small emittance and high intensity of 500 mA. It will provide very bright synchrotron radiation over a large spectral range from IR to hard X-rays. Damping wigglers (DWs) are deployed to reduce the emittance of 2 nm by factors of 2-4, as well as for intense radiation sources for users. The linear and nonlinear effects induced by the DWs are integrated into the lattice design. In this paper, we discuss the linear and nonlinear optimization with DWs, and present a solution satisfying the injection and lifetime requirements. Our approach could be applied to the other light sources with strong insertion devices.

• S.L. Kramer, W. Guo
  BNL, Upton, Long Island, New York

Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886

The NSLS-II light source is a proposed 3 GeV storage ring, with the potential for ultra-low emittance*. The lattice design uses a 30 cell DBA structure with a periodicity of 15, for alternating long and short straight sections. All cells are tuned achromatic to maximize the emittance reduction achieved as damping wigglers are added to the ring. Recent optimization of the lattice consisted of increasing the number of possible hard X-ray beam ports using three pole wigglers, reducing the number of magnets (quadrupoles and sextupoles) and shifting the magnets to allow easier extraction of the photon beams. The impact of the reduction of magnets on the lattice flexibility will be presented in terms of the tuning range possible for the lattice parameters: tune, emittance, and chromaticity, beta function matching to user insertion devices (IDs) and for compensating for ID induced distortions to these parameters. This flexibility is important for optimizing the lattice linear and nonlinear properties, the dynamic aperture, and its impact on beam lifetime, as well as matching the user source requirements and for value engineering of magnets and power supplies.

*Work presented on behalf of the NSLS-II Design Team, CDR(2006), CD2(2007) and CD3(2008).

• T. Summers, D. Chabot, L.O. Dallin, M.J. Sigrist
  CLS, Saskatoon, Saskatchewan

Upgrades to the orbit control system at the Canadian Light Source (CLS) have resulted in increased beam stability and reproducibility. These upgrades include improving position information from the beam position monitors (BPMs) by modifying the data acquisition algorithm and switching to a real-time operating system. Beam motion has been reduced to an RMS deviation of less than 1 micron in both planes. Limiting the maximum corrector step has allowed the use of all singular values when inverting the BPM response matrix, resulting in much better orbit reproducibility. As well, improved lookup tables have been developed to compensate for the effects of changing undulator gaps and polarizations. Presently, work is underway to develop fast orbit correction with rates up to 100 Hz. Fast orbit correction will further reduce the residual perturbations caused by undulator activity and will allow fast ramping of superconducting wigglers.

• E. Huttel, I. Birkel, A.-S. Müller, N.J. Smale, K.G. Sonnad, P. Wesolowski
  FZK, Karlsruhe

The ANKA storage ring is filled at 0.5 GeV and then ramped to 2.5 GeV for regular user operation. A full-energy injection of the ANKA storage ring would have several advantages. The damping at a beam energy of 2.5 GeV is stronger, which will more efficiently fight instabilities during the injection, therefore allowing higher beam currents. With constant magnet settings, the orbit stability would improve significantly. The injection time would be reduced and topping- up operation would become possible. As a consequence, the optical elements of the user beamlines would see a constant power as a function of time which further enhances the overall stability. In this paper, a design for a full energy injector is proposed. The injector will be located inside the storage ring tunnel, similar to the SLS and ALBA design. The focusing is mainly provided by combined function magnets. The full energy injector has a design emittance of 40 nmrad and a circumference of 94.8 m. A modification of the existing storage ring is foreseen to house the necessary more powerful injection elements.

• V.P. Suller, P. Jines, D.J. Launey, T.A. Miller, Y. Wang
  LSU/CAMD, Baton Rouge, Louisiana
• S. Wang
  CAEP/IFP, Mainyang, Sichuan

At the CAMD Light Source a new optic has been developed for the lattice having small vertical beta function in each of the 4 long straight sections. This optic will be necessary to operate the multipole wigglers with small vertical aperture which are planned to be installed in the near future. Results are presented of the tests which have been made with this optic, particularly in the critical area of injection, which is made low energy. The lattice functions have been characterized using LOCO software and the reduced vertical aperture confirmed with an adjustable scraper.

• V.P. Suller, A.J. Crappell, P. Jines, D.J. Launey, T.A. Miller, Y. Wang
  LSU/CAMD, Baton Rouge, Louisiana

To control the emittance coupling in the CAMD Light Source, new power supplies have been constructed which adjust the currents in the individual coils of the normal lattice sextupoles, thereby creating skew quadrupole fields. The new power supplies add or subtract current through the pre-energized coils. Performance contributing factors include a summing network with a temperature coefficient less than 1ppm/°C, a water cooled resistive shunt, and linear optical signal isolation. High density & modularity control boards and water cooled power cards are mounted as pull-out units in a 19” rack. Active limiters and fault indicators can provide reliability and portability to higher power designs. The use of these skew quadrupoles in controlling and minimizing the emittance coupling is presented.

• M. Borland
  ANL, Argonne

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

The X-ray Free Electron Laser Oscillator* (XFEL-O) is a concept for a high-brightness fourth-generation x-ray source with full spatial and temporal coherence. It is based on a CW electron source and superconducting linac. In order to reduce cost and increase versatility, a recirculating linac configuration is being entertained. In this paper, we present an optics design for the four-pass linac and the three recirculation systems. The design goals are preservation of the beam emittance and energy spread, as well as minimal cost and complexity. We also present the results of tracking studies that show the expected performance.

*K.J. Kim et al., Phys. Rev. Letters, to be published.

• M. Ikegami
  KEK, Ibaraki
• H. Ao
  JAEA/LINAC, Ibaraki-ken
• T. Morishita, H. Sako, Y. Yamazaki
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken

The output energy of J-PARC linac is planned to be upgraded from 190 MeV to 400 MeV by adding an ACS (Annular Coupled Structure linac) section. The ACS is a variety of coupled-cavity structure linac newly devised for former JHP (Japan Hadron Project), and its original beam dynamics design for J-PARC was presented in LINAC02 [M. Ikegami et. al., in Procs. of LINAC02, p. 629]. Extensive R&D studies have been conducted since then to establish the feasibility of ACS, where four ACS modules have been fabricated and successfully high-power tested. In parallel, the beam dynamics design of the ACS has been further optimized to reflect the experience obtained in the R&D studies and reduce the cost for mass production. In this paper, the revised beam dynamics design of the J-PARC ACS is presented with some simulation results with a particle simulation code.

• A.V. Shemyakin, A.V. Burov, K. Carlson, L.R. Prost, M. Sutherland, A. Warner
  Fermilab, Batavia

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy

Antiprotons in Fermilab’s Recycler ring are cooled by a 4.3 MeV, 0.1A DC electron beam as well as by a stochastic cooling system. In this paper we will describe electron cooling improvements recently implemented: adjustments of electron beam line quadrupoles to decrease the electron angles in the cooling section and a better stabilization and control of the electron energy.

• G.E. Krafczyk, C.C. Jensen, H. Pfeffer, G.J. Warchol
  Fermilab, Batavia

Fermilab is in the process of upgrading its Booster Correction Element System to include full field correction element magnets to correct position and chromaticity throughout the booster cycle. This upgrade requires power supplies with maximum outputs of ±180V/±65A, with current bandwidths of 5kHz and with slew rates of min to max current in 1ms. For seamless operation around zero current and voltage, we use continuous switching on both sides of the bridge. Although the straightforward way of coordinating the switching on both sides of the bridge can be accomplished with one triangle timing wave and one voltage reference, we have found that using two triangle waves yields a switching coordination that effectively doubles the frequency of the differential ripple on the load and allows for better and cheaper filtering of the output ripple.

• K.-B. Liu, P.C. Chiu, K.T. Hsu, K.H. Hu, Y.-C. Lin, I. Liu, Z.-D. Tsai, C.Y. Wu
  NSRRC, Hsinchu

Corrector magnets of TLS storage ring are served with linear power supplies (corrector magnet power supplies), with some modifications the long-term output current stability and ripple of these linear power supplies were improved from 500 ppm to 50 ppm. But these linear power supplies are very low efficiency、low power factor and about 20Hz low frequency response bandwidth that waste power、noisy and unable to serve fast orbit correction. MCOR30 is a modular switching power converter with smaller volume、high efficiency and above 100Hz frequency response bandwidth, replacing these linear power supplies with MCOR30s that could save power and increasing orbit correction response.

• R. Visintini, M. Cautero, D.M. Molaro
  ELETTRA, Basovizza

Funding: The work was supported in part by the Italian Ministry of University and Research under grant FIRB-RBAP045JF2

FERMI@Elettra is the new 4th-generation light source, based on a single-pass FEL, under construction at the Elettra Laboratory in Trieste, Italy. Some hundreds of magnets and coils need to be supplied along the accelerator sections and the undulators chains - mostly individually - with currents as low as 1.5 A up to 750 A. Starting from a successful design developed at Elettra* for the full-energy injector**, a new version of the existing 4-quadrant, 5 A PS has been studied. This new bipolar low-current PS, with full digital control, will be adopted for all 1.5 A and 5 A loads. The design of a bipolar PS for supplying the 20 A loads is in progress. This paper will describe the proposed PS system for the magnets and coils of FERMI@Elettra. The focus will be on the solutions adopted to minimize the number of different PS types. Particular stress will be laid upon the in-house design.

*D, Molaro et al. - A new bipolar power supply for Elettra booster pre-injector correctors - PCIM08
**R. Visintini et al. - Magnet power converters for the new Elettra full energy injector - EPAC08

• M. Gyr, W. Bartmann, M. Benedikt, B. Goddard, M. Meddahi
  CERN, Geneva
• A. Koschik
  ETH, Zürich
• D. Mayani Parás
  UNAM, México, D.F.

For the proposed PS2 accelerator several extraction systems are needed, including a slow third-integer resonant extraction. The requirements are presented together with the conceptual considerations for the sextupole locations and strengths, the separatrices at the extraction elements and the aperture implications for the overall machine. Calculations of the phase space separatrices have been computed with a new code for the physics of slow resonant extraction, which is briefly reviewed. Implications for the extraction equipment design and for the injection-extraction straight section optics are discussed.

• A. Kiyomichi, T. Adachi, S. Murasugi, R. Muto, H. Nakagawa, J.-I. Odagiri, K. Okamura, H. Sato, Y. Sato, S. Sawada, Y. Shirakabe, H. Someya, K.H. Tanaka, M. Tomizawa, A. Toyoda, E. Yanaoka
  KEK, Tsukuba
• T.I. Ichikawa, K. Mochiki, S. Onuma
  Tokyo City University, Tokyo
• K. Noda
  NIRS, Chiba-shi

J-PARC (Japan Proton Accelerator Research Complex) is a new accelerator facility to produce MW-class high power proton beams at both 3GeV and 50GeV. The Main Ring (MR) of J-PARC can extract beams to the neutrino beam line and the slow extraction beam line for Hadron Experimental Facility. The slow extraction beam is used in various nuclear and particle physics experiments. A flat structure and low ripple noise are required for the spills of the slow extraction. We are developing the spill control system for the slow extraction beam. The spill control system consists of the extraction quadrupole magnets and feedback device. The extraction magnets consist of two kinds of quadrupole magnets, EQ (Extraction Q-magnet) which make flat beam and RQ (Ripple Q-magnet) which reject the high frequent ripple noise. The feedback system, which is using Digital Signal Processor (DSP), makes a ramping pattern for EQ and RQ from spill beam monitor. Here we report the construction status of the extraction magnets and the development of the feedback system.

• B.-S. Park, Y.-S. Cho, B.H. Choi, I.-S. Hong, J.-H. Jang, H.S. Kim, K. R. Kim, H.-J. Kwon, H.R. Lee, S.P. Yun
  KAERI, Daejon

Funding: This work is supported by the Ministry of Education, Science and Technology of Korea.

PEFP (Proton Engineering Frontier Project) beamlines will be supplied either 20-MeV or 100-MeV proton beams from the 100-MeV proton linear accelerator for beam applications. Each proton beam will be transported to 2 beamlines for industrial purpose and 3 beamlines for the researches. Beam distribution to 3 research beam lines will be conducted sequentially by programmable AC magnet. To provide flexibility of the irradiation conditions, each beam line is designed to have specific beam parameters. We have designed the beamlines to the targets for wide or focused beams, external or in-vacuum beams, and horizontal or vertical beams. The detail design of each beamline will be reported.

• M.W. McGee, T.T. Arkan, E. Borissov, J.R. Leibfritz, W. Schappert
  Fermilab, Batavia
• S. Barbanotti
  INFN/LASA, Segrate (MI)

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy.

In an exchange of technology agreement, Deutsches Elektron-Synchrotron (DESY) Laboratory in Hamburg Germany has provided a 1.3 GHz cryomodule “kit” to Fermilab. The cryomodule components (qualified dressed cavities, cold mass parts, vacuum vessel, etc.) sent from Germany in pieces were assembled at Fermilab’s Cryomodule Assembly Facility (CAF). The cavity string was assembled at CAF-MP9 Class 10 cleanroom and then transported to CAF-ICB cold mass assembly area via a flatbed air ride truck. Finite Element Analysis (FEA) studies were implemented to define location of instrumentation for initial coldmass transport, providing modal frequencies and shapes. Subsequently, the fully assembled cryomodule CM1 was transported to the SRF Accelerator Test Facility at New Muon Lab (NML). Internal geophones (velocity sensors) were attached during the coldmass assembly for transport (warm) and operational (cold) measurements. A description of the isolation system that maintained alignment during transport and protected fragile components is provided. Shock and vibration measurement results of each transport and modal analysis are discussed.

• Q. Zhao, V.A. Andreev, J. Brandon, G. Machicoane, F. Marti
  NSCL, East Lansing, Michigan

Funding: Michigan State University

The National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) is implementing a system called the ReA3 to reaccelerate rare isotope beams from projectile fragmentation to energies of about 3 MeV/u. The 80.5 MHz triple-harmonic buncher before the ReA3 Radio Frequency Quadrupole (RFQ) linac has recently been implemented and measurements made. Tests using beams from the Electron Cyclotron Resonance (ECR) ion source test stand are being performed. The beam properties after the buncher are fully characterized using various diagnostic tools (e.g. fast Faraday cup, energy analyzer, emittance scanner). As a result, the tuning procedures for the buncher operations are developed. We will present the detailed results of the beam based buncher studies and compare them with simulations.

• J.W. Glenn, H. Huang, A.K. Jain, C.J. Liaw, I. Marneris, W. Meng, J.-L. Mi, S.P. Pontieri, P.J. Rosas, J. Sandberg, J.E. Tuozzolo, W. Zhang
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC underContract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

In order to cross more rapidly the 82 weak resonances caused by the horizontal tune and the partial snakes, we plan to jump the horizontal tune 82 times during the acceleration cycle, 41 up and 41 down*. To achieve this, the magnets creating this tune jump will pulse on in 100 micro-seconds, hold the current flat for about four milli-seconds and zero the current in another 100 micro-seconds. The magnets are old laminated beam transport magnets with longitudinal shims closing the aperture to reduce inductance and power supply current. The power supply uses a high voltage capacitor discharge to raise the magnet current, which is then switched to a low voltage supply, and then the current is switched back to the high voltage capacitor to zero the current. The current in each of the magnet pulses must match the order of magnitude change in proton momentum during the acceleration cycle. The magnet, power supply and cabling will be described with coast saving features and operational experience.

*Overcome Horizontal Depolarizing Resonances in the AGS with Tune Jump

• L. Faillace, L. Palumbo
  Rome University La Sapienza, Roma
• P. Frigola
  RadiaBeam, Marina del Rey
• A. Fukasawa, B.D. O'Shea, J.B. Rosenzweig
  UCLA, Los Angeles, California
• B. Spataro
  INFN/LNF, Frascati (Roma)

We present here the design, including RF modelling, cooling, and thermal stress and frequency detuning, of an S-band RF gun capable of running near 500 Hz, for application to FEL and inverse Compton scattering sources. The RF design philosophy incorporates many elements in common with the LCLS gun, but the approach to managing cooling and mechanical stress diverges significantly. We examine the new proprietary approach of RadiaBeam Technologies for fabricating copper structures with intricate internal cooling geometries. We find that this approach may enable very high repetition rate, well in excess of the nominal project this design is directed for, the SPARX FEL.

*C.Limborg et al.,“RF Design of the LCLS Gun”,LCLS Technical Note LCLS-TN-05-3
**P. Frigola et al.,“A Novel Fabrication Technique for the Production of RF Photoinjectors”,published in EPAC08.

Slides

• H. Kobayashi
  KEK, Ibaraki

The J-PARC accelerator comprises a 400 MeV linac, a 3-GeV Rapid Cycling Synchrotron (RCS) and a Main Ring (MR). In the linac, an H^- ion beam was successfully accelerated to 181 MeV, the design target for the first step in Phase I, on January 24, 2007. Subsequently, full beam energy of 3 GeV was achieved in the RCS on October 31, 2007. The first beam commissioning of the MR was carried out in May and June 2008. Injection, circulation with rf capture and extraction to the injection beam dump were successfully performed. Some other basic tunings such as COD correction and chromaticity correction were also done well. In the MR, there are two extraction sections. One is for the Hadron Experimental Facility for which slow extraction will be mainly used and the other for neutrino experiment, which requires fast beam extraction. After confirming the basic performance of beam injection and beam circulation with rf capture, we have installed all devices for these two extraction sections and have progressed fine-tuning of ramp-up patterns of power supplies. Beam acceleration will start from December 2008. The first result of beam acceleration and extraction will be reported.

Slides

• V. Sajaev
  ANL, Argonne

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

The response matrix fit is routinely used at APS for linear optics correction. The high accuracy of the method enables us to measure the variation of betatron phase advance around the ring with rf frequency. This variation can be used to calculate local chromaticity. Such measurements were first performed at the APS at the moment when a sextupole was mistakenly connected with the wrong polarity. Local chromaticity calculations clearly pointed to the location of the sextupole error. Results and details of the measurements are reported and discussed.

Slides

• N. Eddy, J.L. Crisp, I. Kourbanis, K. Seiya, R.M. Zwaska
  Fermilab, Batavia
• S. De Santis
  LBNL, Berkeley, California

The production of an Electron Cloud poses stability issues for future high intensity running of the Fermilab Main Injector. Recent experiements have shown the presense of the electron cloud can be detected by the phase shift of a TE wave propagated along the beampipe. This technique has been employed to provide very sensitive measurements of the electron cloud development in the Fermilab Main Injector.

Slides

• E. Bravin
  CERN, Geneva

During the 2008 LHC injection synchronisation tests and the subsequent days with circualting beam, the majority of the LHC beam instrumentation systems were capable of measuring their first beam parameters. This includes the two large, distributed, beam position and beam loss systems, as well as the scitillating and OTR screen systems, the fast and DC beam current transformer systems, the tune measurement system and the wire scanner system. The fast timing system was also extensively used to synchronise most of this instrumentation. This paper will comment on the results to date, some of the problems observed and improvements to be implemented before the next LHC run.

Slides

• D.P. Missiaen, J.-P. Quesnel, R.J. Steinhagen
  CERN, Geneva

The Large Hadron Collider (LHC) has been aligned using classical and non-standard techniques. The results have been seen on September 10th, 2008, the day when the beam made several turns in the machine with very few correctors activated. The paper will present the different steps of the alignment, from the metrological measurements done during the phase of the magnets assembly to the alignment itself in the tunnel as well as the techniques used to obtain the accuracy required by the physicists. The correlation of the results of this alignment with the position of the beam seen on the BPMs by the operation team during the days the beam has circulated will be presented.

Slides

• M. Mehler, H. Klingbeil, M. Kumm, U. Laier, K.-P. Ningel
  GSI, Darmstadt

Funding: Project funded by the European Community under the FP6 "Structuring the European Research Area" program (SIS100₂, contract number 515873)

SIS100 is a synchrotron that will be built in the scope of the FAIR (Facility for Antiproton and Ion Research) project. High intensity ion beams are required, making it necessary to damp longitudinal coupled and uncoupled bunch oscillations. For this purpose, a closed-loop control system was designed. Its processing part is based on digital signal processors (DSP) and field programmable gate arrays (FPGA) whose advantage is their adaptability to different problems by software changes. Experiments with a prototype were performed at the existing synchrotron SIS12/18 at GSI concentrating on the damping of longitudinal coupled bunch quadrupole oscillations of the lowest order. The configuration of the electronic system is described and results of the machine development experiments are reported. Finally, an outlook to the application in SIS100 is given.

• H.C. Chao, H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, H.-J. Tsai
  NSRRC, Hsinchu

The design work of the concentric booster for Taiwan Photon Source (TPS) has been well in progress. The circumference is 496.8 m. It consists of modified FODO cells with defocusing quadrupole and sextupole fields built in bending magnets, and combined function focusing quadrupoles with imbedded focusing sextupole. The emittance is about 10 nm-rad at 3 GeV. Several modifications on the structure were made to improve the beam dynamics behaviors. Good dynamic aperture and nonlinear behavior as well as good tunability are shown. The efficient closed orbit correction scheme is presented. The repetition rate is 3 Hz, and the eddy current effect is also discussed.

• C.-C. Kuo, H.-P. Chang, H.C. Chao, P.J. Chou, G.-H. Luo, H.-J. Tsai
  NSRRC, Hsinchu

A 3 GeV synchrotron light source is planned to be built at the existing site of NSRRC campus. The project is called the Taiwan Photon Source (TPS). It will provide x-ray photon beam with brilliance several orders higher than the one generated by the existing 1.5 GeV synchrotron. The design issues of accelerator lattice for the 3 GeV storage ring and booster injector will be presented. These issues cover the properties of linear and nonlinear beam dynamics, the optimization of dynamic aperture and momentum acceptance, collective beam instabilities and lifetime issues, the effects caused by various error sources and technical measures to suppress these error effects, etc.

• M. Böge, A. Lüdeke, A. Streun
  PSI, Villigen
• Å. Andersson
  MAX-lab, Lund

Utilizing a large number of non-dispersive (24) and dispersive (6) skew quadrupoles the betatron coupling and the vertical spurious dispersion can be simultaneously reduced to extremely small values. As a result the achieved vertical emittance begins to approach its ultimate limit, set by the fundamental quantum nature of synchrotron radiation, which in the SLS case is ~0.55 pm.rad. At the same time emittance measurements based on the fitting of a diffraction limited vertical photon beam from a dipole have been pushed to the limit in order to verify this ultra-low vertical emittance.

• A. Streun, M. Böge, J.T.M. Chrin, A. Lüdeke
  PSI, Villigen

Recently the energy acceptance and Touschek lifetime of the storage ring of the Swiss Light Source (SLS) could be successfully set to values in agreement with simulations for an ideal lattice. This was finally achieved through control of linear coupling and symmetrization of the sextupole pattern. 36 small corrector magnets were installed for this purpose as additional windings on the ring sextupoles: 30 skew quadrupoles (24 at zero and 6 at maximum dispersion) and 6 auxiliary sextupoles. Base for the success of these measures were previous corrections of dipolar and quadrupolar errors, which we will summarize briefly.

• Y. Iwasaki, T. Kaneyasu, S. Koda, Y. Takabayashi
  SAGA, Tosu
• H. Ohgaki
  Kyoto IAE, Kyoto

The procedure of accelerator modeling using orbit response matrix fitting is well known and widely adopted at many light sources, we also examined the model fitting to diagnose optics and to restore the periodicity of the storage ring optics. In the modeling procedure we used the tracking code TRACY2, because it can calculate the orbit response matrix including energy offset caused by the dipole kick. The multi-parameter fitting was carried out by using SVD algorism implemented in the Labview mathematical package. In the fitting procedure, we fixed a steering magnet field to the value obtained from the orbit measurement using screen monitor to avoid explicit solution between the steering strengths and the BPM gains. By adopting the orbit response matrix fitting, it was found that the quadrupole strength is about 3-5% larger than the calculated value obtained from magnetic measurement data and output current of the power supply. In the conference, we will report on the result of the modeling procedure and its application to the optics correction.

• K.J. Bertsche, P. Emma
  SLAC, Menlo Park, California
• O.A. Shevchenko
  BINP SB RAS, Novosibirsk

Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515.

For proper operation of the LCLS x-ray free-electron laser, measurement and control of the electron bunch longitudinal phase space is critical. The LCLS accelerator includes two bunch compressor chicanes to magnify the peak current. These magnetic chicanes can generate significant coherent synchrotron radiation (CSR), which can distort the phase space distribution. We propose a diagnostic scheme by exciting a weak skew quadrupole at an energy-chirped, high dispersion point in the first bunch compressor (BC1) to reconstruct longitudinal phase space on an OTR screen after BC1, allowing a detailed characterization of the CSR effects.

• F.-J. Decker, R. Akre, K.J. Bertsche, A. Brachmann, W.S. Colocho, Y.T. Ding, D. Dowell, P. Emma, J.C. Frisch, A. Gilevich, G.R. Hays, P. Hering, Z. Huang, R.H. Iverson, A. Krasnykh, H. Loos, H.-D. Nuhn, D.F. Ratner, H. Smith, J.L. Turner, J.J. Welch, W.E. White, J. Wu
  SLAC, Menlo Park, California

Funding: Work supported by Department of Energy contract DE-AC03-76SF00515.

The electron beam for the Linac Coherent Light Source (LCLS) at SLAC is accelerated by disk-loaded RF structures over a length of 1 km. The mainly longitudinal field can sometimes exhibit transverse components, which kick the beam in x and/or y. This is normally a stable situation, but when a klystron, which powers some of these structures, has to be switched off and another one switched on, different kicks can lead to quite a different orbit. Some klystrons, configured in an energy and bunch length feedback, caused orbit changes of up to 1 mm, which is about 20 times the σ beam size. The origins and measurements of these kicks and some efforts (orbit bumps) to reduce them will be discussed.

• M. White, J.T. Collins, P.K. Den Hartog, M.S. Jaski, G. Pile, B.M. Rusthoven, S.E. Shoaf, S.J. Stein, E. Trakhtenberg, J.Z. Xu
  ANL, Argonne

Funding: Work at Argonne was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No DE-AC02-06CH11357.

The Linac Coherent Light Source (LCLS), now being commissioned at the Stanford Linear Accelerator Center (SLAC) in California, and coming online for users in the very near future, will be the world’s first x-ray free-electron laser user facility. Design and production of the undulator system was the responsibility of a team from the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). A sophisticated, five-axis, computer-controlled support and motion system positions and stabilizes all beamline components in the undulator system. The system also enables undulators to be retracted from the beam by 80 mm without disturbing the rest of the beamline components. An overview of the support and motion system performance, including achieved results with a production unit that was reserved at Argonne for this purpose, is presented.

• S. Matsuba
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima
• K. Harada, Y. Kobayashi, T. Miyajima, S. Nagahashi, T. Obina, M. Shimada, R. Takai
  KEK, Ibaraki

A fast local bump system for the helicity switching of a circular/linear polarized undulator (CPU) has been developed at the Photon Factory storage ring (PF-ring). The system consists of five identical bump magnets and tandem APPLE-2 type CPUs. In addition, fast correction magnets for a leakage of the bump were prepared. We designed the bump magnets with a core length of 0.15 m, a pole gap of 21 mm and the coils of 32 turns, which were excited by bipolar power supplies with a capacity of ±100 A and ±50 V since a switching frequency of more than 10 Hz and a bump angle of 0.3 mrad were required for user experiments. The bump magnets and one of CPUs were installed at PF-ring in March 2008, and the experiments for the machine development using a stored beam have been progressed. In this conference, we present the first experimental results with the bump system.

• F.C. Pilat, M. Bai, D. Bruno, P. Cameron, K.A. Drees, V. Litvinenko, Y. Luo, N. Malitsky, G.J. Marr, A. Marusic, V. Ptitsyn, T. Satogata, S. Tepikian, D. Trbojevic
  BNL, Upton, Long Island, New York

The reduction of beta* beyond the 1m design value at RHIC has been consistently achieved over the last 6 years of RHIC operations, resulting in an increase of luminosity for different running modes and species. During the recent 2007-08 deuteron-gold run the reduction to 0.70 from the design 1 m achieved a 30% increase in delivered luminosity. The key ingredients in allowing the reduction have been the capability of efficiently developing ramps with tune and coupling feedback, orbit corrections on the ramp, and collimation at injection and on the ramp, to minimize beam losses in the final focus triplets, the main aperture limitation for the collision optics. We will describe the operational strategy used to reduce the b*, at first squeezing the beam at store, to test feasibility, followed by the operationally preferred option of squeezing the beam during acceleration, and the resulting luminosity increase obtained in the Cu-Cu run in 2005, Au-Au in 2007 and the deuteron-Au run in 2007-08. We will also include beta squeeze plans and results for the upcoming 2009 run with polarized protons at 250 GeV.

• H. Burkhardt, Y.I. Levinsen, S.M. White
  CERN, Geneva

The TOTEM experiment requires special high beta optics solutions. We report on studies of optics for an intermediate beta* = 90 m, as well as a solutions for a very high beta* of 1540 m, which respect all known constraints. These optics are rather different from the normal physics optics and will require global tune changes or adjustments.

• R. Tomás, M. Aiba, S.D. Fartoukh, F. Franchi, M. Giovannozzi, V. Kain, M. Lamont, G. Vanbavinckhove, J. Wenninger, F. Zimmermann
  CERN, Geneva
• R. Calaga
  BNL, Upton, Long Island, New York
• A. Morita
  KEK, Ibaraki

In 2008 beam successfully circulated in the LHC. Thanks to an excellent functioning of the BPM system and the related software, injection oscillations were recorded for the first 90 turns at all BPMs. The analysis of these data gives the unique opportunity of evaluating the periodic optics and inferring possible error sources.

• E.H.M. Wildner, F. Cerutti, A. Ferrari, A. Mereghetti, E. Todesco
  CERN, Geneva
• F. Broggi
  INFN/LASA, Segrate (MI)

Recent studies show that the energy deposition for the LHC phase one luminosity upgrade, aiming at a peak luminosity 2.5 10³⁴ cm^-2s^-1, can be handled by appropriate shielding. The phase II upgrade aims at a further increase of a factor 4, possibly using Nb3Sn quadrupoles. This paper describes how the main features of the triplet layout, such as quadrupole lengths, gaps between magnets, and aperture, affect the energy deposition in the insertion. We show the dependence of the triplet lay-out on the energy deposition patterns in the insertion magnets. An additional variable which is taken into account is the choice of conductor, i.e. solutions with Nb-Ti and Nb3Sn are compared. Nb3Sn technology gives possibilities for increasing the magnet apertures and space for new shielding solutions. Our studies give a first indication on the possibility of managing energy deposition for the phase II upgrade.

• F. Zimmermann, S.D. Fartoukh, M. Giovannozzi, V. Kain, M. Lamont, Y. Sun, R. Tomás
  CERN, Geneva
• R. Calaga
  BNL, Upton, Long Island, New York

In early LHC commissioning, linear and "higher-order" polarity checks were performed for one octant per beam, by launching suitable free betatron oscillations and then inverting a magnet-circuit polarity or strength. Circuits tested included trim quadrupoles, skew quadrupoles, lattice sextupoles, sextupole spool-pieces, Landau octupoles, and skew sextupoles. A nonzero momentum offset was introduced to enhance the measurement quality. The low-intensity single-pass measurements proved sufficiently sensitive to verify the polarity and the amplitude of (almost) all circuits under investigation, as well as the alignment of individual trim quadrupoles. A systematic polarity inversion detected by this measurement helped to pin down the origin of observed dispersion errors. Later, the periodic "ring dispersion" was reconstructed from the full first-turn trajectory of an injected off-momentum beam, by removing, at each location, the large incoming dispersion mismatch, forward-propagated via the optics model. Various combinations of inverted trim quadrupoles were considered in this model until reaching a good agreement of reconstructed dispersion and prediction.

• S. Cavalier, M. Heller
  LAL, Orsay
• H. Burkhardt, P.M. Puzo, S.M. White
  CERN, Geneva

For luminosity and total cross section measurement, the standard LHC physics optics has been modified for the ATLAS experiment in the so-called high beta optics with a beta star of 2600m. The high beta optics takes into account the whole LHC ring. Protons are, then, tracked from the Interaction Point to the detectors. Tolerances on the beta star are given and the effect of misalignment errors is checked. We show the final High beta optics used and the impact of the misalignment effect on the measurement.

• H. Koiso, A. Morita, Y. Ohnishi, K. Oide
  KEK, Ibaraki

Lattice design for SuperKEKB is based on the present KEKB lattice. The unit-cell structure of KEKB has a wide range of flexibility, therefore main beam-optical parameters can be adjusted without changing the arcs. The interaction region (IR) and the other straight sections are changed to squeeze the vertical beta function to 3 mm at IP, keeping sufficient dynamic apertures. Recent progress such as a new design of IR with superconducting quadrupole magnets at 1.9 K, traveling focus scheme by using crab cavities, local chromaticity correction for the high energy ring, is presented.

• M.K. Sullivan, K.J. Bertsche, J. Seeman, U. Wienands
  SLAC, Menlo Park, California
• S. Bettoni
  CERN, Geneva
• M.E. Biagini, P. Raimondi
  INFN/LNF, Frascati (Roma)
• E. Paoloni
  University of Pisa and INFN, Pisa

Funding: Work supported by the Department of Energy under contract number DE-AC03-76SF00515.

We present an improved design for a Super-B interaction region. The new design minimizes local bending of the two colliding beams by separating all beam magnetic elements near the Interaction Point (IP). The total crossing angle at the IP is increased from 50 mrad to 60 mrad. The first magnetic element is a six slice Permanent Magnet (PM) quadrupole with an elliptical aperture allowing us to increase the vertical space for the beam. This magnet starts 36 cm from the Interaction Point (IP). This magnet is only seen by the Low-Energy Beam (LEB), the High-Energy Beam (HEB) has a drift space at this location. This allows the preliminary focusing of the LEB which has a smaller beta y* at the IP than the HEB. The rest of the final focusing for both beams is achieved by two super-conducting side-by-side quadrupoles (QD0 and QF1). These sets of magnets are enclosed in a warm bore cryostat located behind the PM quadrupole for the LEB. We describe this new design for the interaction region.

• V. Ptitsyn, A.J. Della Penna, V. Litvinenko, N. Malitsky, T. Satogata
  BNL, Upton, Long Island, New York

Funding: Work performed under US DOE contract DE-AC02-98CH1-886

During the course of last RHIC runs the beta-functions at the collision points (beta*) have been reduced gradually to 0.7m. In order to maximize the collision luminosity and ensure the agreement of the actual machine optics with the design one, more precise measurements and control of beta* value and beta* waist location became necessary. The paper presents the results of the implementation of the technique applied in last two RHIC runs. The technique is based on well-known relation between the tune shift and the beta function and involves precise betatron tune measurements using BBQ system as well as specially developed knobs for beta* and beta* waist location control.

• A. Scarfe, R. Appleby
  UMAN, Manchester
• D. Angal-Kalinin, J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

The Accelerator Test Facility (ATF2) at KEK aims to experimentally verify the local chromaticity correction scheme to achieve a vertical beam size of 37nm. The facility is a scaled down version of the final focus design proposed for the future linear colliders. In order to achieve this goal, high precision tuning methods are being developed. One of the methods proposed for ATF2 is a novel method known as the ‘rotation matrix’ method. Details of the development and testing of this method, including orthogonality optimisation and simulation methods, are presented.

• I. Melzer-Pellmann, D. Kruecker, F. Poirier, N.J. Walker
  DESY, Hamburg

Funding: This work is supported by the Commission of the European Communities under the 6th Framework Programme "Structuring the European Research Area", contract number RIDS-011899.

The International Linear Collider (ILC) relies on very high beam powers and very small beam emittance to achieve the ambitious luminosity of 2·10⁺³⁴ cm^-2s^-1. The potential for damage to the accelerator hardware in the event of some machine failure will require a sophisticated machine protection system. The small apertures in the Beam Delivery System (BDS) - specifically the collimators (by definition the smallest apertures in the machine) are particularly critical. Possible failures in the Main Linac of the ILC and their impact on the BDS are studied using the MERLIN C++ library*. We show that the machine is safe for at least one bunch in case of one of the described failures; a fast abort system is designed to safely extact the remainder of the bunches in the pulse to a dump. Investigated are phase and voltage shifts of the klystrons, quadrupole and corrector coil failures.

*Merlin - A C++ Class Library for Accelerator Simulations; http://www.desy.de/~merlin.

• M. Alabau, P. Bambade, G. Le Meur, F. Touze
  LAL, Orsay
• A. Faus-Golfe
  IFIC, Valencia
• S. Kuroda
  KEK, Ibaraki
• M. Woodley
  SLAC, Menlo Park, California

Since several years, the vertical beam emittance measured in the Extraction Line (EXT) of the Accelerator Test Facility (ATF) at KEK, has been significantly larger than that measured in the damping ring (DR) itself. The EXT line that transports the beam to the ATF2 Final Focus beam line has been rebuilt, but the extraction itself remains in most part unchanged, with the extracted beam transported off-axis horizontally in two of the quadrupoles, beyond the linear region for one of them. A few other nearby magnets have also modelled or measured non-linearity. In case of a residual vertical beam displacement, this can result in increased vertical emittance through coupling between the two transverse planes. Tracking studies as well as measurements have been carried out to study this effect and the induced sensitivity of beam optical parameters to the trajectory at injection, in view of deriving tolerances for reproducible and stable operation.

• G.M. Wang, K.B. Beard, R.P. Johnson
  Muons, Inc, Batavia
• S.A. Bogacz
  JLAB, Newport News, Virginia
• G.M. Wang
  ODU, Norfolk, Virginia

Funding: Supported in part by USDOE STTR Grant DE-FG02-08ER86351

We have previously considered the application of fast pulsing quadrupoles to increase the focusing of muon beams as they gain energy in the linac region of a recirculating linear accelerator (RLA) in order to allow more passes. In this work we consider the use of pulsed magnets, both quads and dipoles, to reduce the number of beam lines needed for the return arcs of the RLA. We investigate the required relationships between the linac parameters (length and energy gain) and the momentum acceptance of the return arcs and consider the optimum strategy for accelerating both muon charge signs.

• S.A. Bogacz
  JLAB, Newport News, Virginia
• R.P. Johnson, G.M. Wang
  Muons, Inc, Batavia

Funding: Supported in part by USDOE STTR Grant DE-FG02-08ER86351

Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses International Linear Collider (ILC) RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discus the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed Linac quadrupoles to allow the maximum number of passes.

• D. L. Rubin, D. Sagan, J.P. Shanks
  CLASSE, Ithaca, New York

Funding: Work supported by the National Science Foundation and the US Department of Energy

The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) for the investigation of the beam physics of a linear collider damping ring. The low beta interaction region optics have been replaced with simple FOFO lattice structures. Superconducting damping wigglers are located in straights where horizontal dispersion can be constrained to be zero to minimize horizontal emittance. The flexibility of the CESR optics allows for an energy reach of 1.5 GeV /beam→ 6.0GeV/beam and a wide range of emittances and radiation damping times. We exploit that flexibility for measurements of the dependencies of various phenomena, on energy, emittance, and damping rate. At 2GeV beam energy, with no damping wigglers, the minimum horizontal emittance is 10nm. With 16 meters of wiggler magnets operating at 1.9 T, the horizontal emittance is reduced by a factor of four to 2.5 nm and the radiation damping time to 56ms. With tuning and alignment we expect to reach a vertical emittance approaching that of the International Linear Collider (ILC) damping rings. We report on the details of the CesrTA optics and the measurements of optical parameters.

• J.P. Shanks, M.G. Billing, S.S. Chapman, M.J. Forster, S.B. Peck, D. L. Rubin, D. Sagan, J.W. Sexton
  CLASSE, Ithaca, New York

Funding: Support provided by the US National Science Foundation and the US Department of Energy.

The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) for low emittance damping ring R&D for the International Linear Collider (ILC). We are developing low emittance tuning techniques with a goal of 1) achieving a vertical emittance approaching that of the ILC damping rings and 2) Gaining an understanding of the effectiveness of those techniques. We will use gain mapping to characterize beam position monitor (BPM) electrode gains, orbit response analysis to determine BPM button misalignments, betatron phase and coupling measurements to characterize optical errors, and orbit and dispersion measurements to locate sources of vertical dispersion. We are investigating a nondestructive dispersion measurement that depends on exciting a synchrotron oscillation and monitoring the phase and amplitude at each BPM. We have developed the analysis tools necessary to correct magnet and alignment errors. An x-ray beam size monitor is being deployed that will allow us to monitor vertical emittance in real time, allowing for empirical tuning of beam size. We will describe the measurement and correction techniques and show data demonstrating their efficacy.

• Y. Papaphilippou, F. Antoniou
  CERN, Geneva
• E.B. Levichev, S.V. Sinyatkin, P. Vobly, K. Zolotarev
  BINP SB RAS, Novosibirsk
• P. Raimondi
  INFN/LNF, Frascati (Roma)

Optics design optimisation studies have been undertaken for the CLIC damping ring lattice. Main parameters such as the ring energy and output longitudinal emittance were reconsidered in order to reduce the detrimental effect of collective instabilities. In this respect, the low emittance arc cell length was rationalized taking into account space and magnet design requirements. The straight section cell filled with super-conducting wigglers was modified to accommodate a robust absorption scheme. Several low emittance rings were considered and compared with respect to their dynamic aperture and the IBS-dominated output emittances.

• L.J. Tavian
  CERN, Geneva

Following the incident on a LHC sector due to an electrical arc on the main dipole bus-bar circuit, post-mortem analysis of previous current plateaus has shown abnormal temperature drift in the helium II baths of some magnets in the concerned area. In order to identify other possible risky areas, a detection system based on calorimety using available precision cryogenic thermometers has been first validated by applying calibrated heating in the magnet cold-mass and then implemented in the different sectors. On the 3-km long continuous helium II cryostat of each LHC sector, this method allows detecting abnormal dissipations in the W-range , i.e. additional resistive heating due to abnormal resistance of about 20 nΩ at 7 kA and less than 10 nΩ at nominal current. The paper describes the principle and the methodology of this calorimetric method and gives the results obtained on the LHC sectors.

• F. Cerutti, F. Borgnolutti, A. Ferrari, A. Mereghetti, E.H.M. Wildner
  CERN, Geneva

While the Large Hadron Collider (LHC) at CERN is starting operation with beam, aiming to achieve nominal performance in the shortest term, the upgrade of the LHC interaction regions is actively pursued in order to enhance the physics reach of the machine. Its first phase, with the target of increasing the LHC luminosity to 2-3 10³⁴ cm^-2 s^-1, relies on the mature Nb-Ti superconducting magnet technology and is intended to maximize the use of the existing infrastructure. The impact of the increased power of the collision debris has been investigated through detailed energy deposition studies, considering the new aperture requirements for the low-beta quadrupoles and a number of other elements in the insertions. Effective solutions in terms of shielding options and design/layout optimization have been envisaged and the crucial factors have been pointed out.

• V.P. Previtali, R.W. Assmann, S. Redaelli
  CERN, Geneva
• V.P. Previtali
  EPFL, Lausanne
• I.A. Yazynin
  IHEP Protvino, Protvino, Moscow Region

The UA9 experiment at the SPS aims at testing bent crystals for usage as collimators with high energy stored proton and heavy ion beams. The experiments will try to establish crystal-based cleaning efficiency with slowly diffusing beam halo. One method for evaluating efficiency relies on Roman Pots and is described elsewhere. An alternative method relies on observing the beam loss signals around the ring. Comparisons of losses escaping from standard collimators and bent crystals will allow determination of cleaning efficiency, equivalent to the definition used for the LHC collimation design. This alternative method is described and simulations with LHC collimation tracking tools for UA9 are discussed. The predicted beam losses along the SPS ring are presented for different orientations and amorphous layer thicknesses of the crystal. The effect of different diffusion speeds for the beam are discussed.

• J.-L. Fernandez-Hernando, D. Angal-Kalinin
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• R. Losito, V. Vlachoudis
  CERN, Geneva

Linac4 is a 160 MeV H^- linac which will replace the existing Linac2, a 50 MeV proton linac, at CERN as a first step of the upgraded LHC proton injector chain. No collimation system is foreseen in the baseline design but it will become mandatory for opreation at highest duty cycle in order to reduce activation of the machine. Such a system will also help to reduce activation at low duty cycle. A review of different collimation options, initial studies on collimator designs capable of intercepting beam power of 10, 25 and 50 Watts at energies between 50 and 160 MeV, the activation of such designs and the downstream elements are shown in this paper.

• B. Bellesia, M.P. Casas Lino, R. Denz, C. Fernandez-Robles, M. Pojer, R.I. Saban, R. Schmidt, M. Solfaroli Camillocci, H. Thiesen, A. Vergara-Fernández
  CERN, Geneva

The Large Hadron Collider has 1572 superconducting circuits which are distributed along the eight 3.5 km LHC sectors. Time and resources during the commissioning of the LHC technical systems were mostly consumed by tests of each circuit of the collider: the powering tests. The tests consisted in carrying out several powering cycles at different current levels for each superconducting circuit. The Hardware Commissioning Coordination was in charge of planning, following up and piloting the execution of the test program. The first powering test campaign was carried out in summer 2007 for sector 7-8 with an expected duration of 12 weeks. The experience gained during these tests was used by the commissioning team for minimising the duration of the following powering campaigns to comply with the stringent LHC Project deadlines. Improvements concerned several areas: strategy, procedures, control tools, automatisation, resource allocation led to an average daily test rate increase from 25 to 200 tests per day. This paper describes these improvements and details their impact on the operation during the last months of LHC Hardware Commissioning.

• R.J. England, E.R. Colby, C. McGuinness, R.J. Noble, R. Siemann, J.E. Spencer, D.R. Walz
  SLAC, Menlo Park, California
• R. Ischebeck
  PSI, Villigen
• T. Plettner
  Stanford University, Stanford, California
• C.M.S. Sears
  MPQ, Garching, Munich

Funding: DOE Grants DE-AC02-76SF00515, DE-FG06-97ER41276

An experimental effort is currently underway at the SLAC National Accelerator Laboratory to focus a 50pC, 60 MeV electron beam into the hollow core of a commercial photonic bandgap fiber. The wakefield radiation produced in the fiber will be spectrally analyzed using a spectrograph in order to detect the frequency signatures of fiber modes that could be used as accelerating modes in a laser-driven fiber-based accelerator scheme. We discuss the current status of the experiment, including efforts to successfully focus the electron beam through the fiber aperture and to collect the produced wakefield radiation.

• V. Yakimenko, M. Babzien, A.V. Fedotov, K. Kusche, J.H. Park, I. Pogorelsky
  BNL, Upton, Long Island, New York
• P. Muggli
  UCLA, Los Angeles, California

Trains of subpicosecond electron bunches are essential to reach high transformer ratio and high efficiency in compact, beam-driven, plasma-based accelerators. These trains with a correlated energy chirp can also be used in pump-probe experiments driven by FELs. We demonstrate experimentally for the first time that such trains with controllable bunch-to-bunch spacing, bunch length, and charge can be produced using a mask technique. With this simple mask technique, the stability of the bunch train in energy and time is guaranteed by the beam feedback system.

Slides

• S.M. Wiggins, M.P. Anania, E. Brunetti, S. Cipiccia, B. Ersfeld, M.R. Islam, R.C. Issac, D.A. Jaroszynski, G. Raj, R.P. Shanks, G. Vieux, G.H. Welsh
  USTRAT/SUPA, Glasgow
• W.A. Gillespie
  University of Dundee, Nethergate, Dundee, Scotland
• A. MacLeod
  UAD, Dundee

Funding: The U.K. EPSRC and the European Community - New and Emerging Science and Technology Activity under the FP6 “Structuring the European Research Area” programme (project EuroLEAP, contract number 028514)

The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme* is developing laser-plasma accelerators for the production of ultra-short electron beams as drivers of incoherent and coherent radiation sources from plasma and magnetic undulators**. Initial quantitative measurements of the electron beam properties have been made. A high power (20 TW) femtosecond laser pulse is focused into a gas jet (length 2 mm) and electrons from the laser-induced plasma are self-injected into the accelerating potential of the plasma density wake behind the laser pulse. The electron beam pointing as it exits the gas jet is as large as 10 mrad. Understanding the pointing stability is an essential step for reproducible beam transport and we present a theoretical model to account for this behaviour. The beam divergence is as low as 2 mrad, which is consistent with a normalised emittance of the order of 1 pi mm mrad. The maximum central energy of the beam is ~90 MeV with r.m.s. relative energy spread as low as 0.8%. An analysis of this unexpectedly high beam quality is presented and its impact on the viability of a free-electron laser*** driven by such a beam is examined.

* D. A. Jaroszynski et al., Phil. Trans. R. Soc. A 364, 689 (2006).
** H.-P. Schlenvoigt et al., Nature Phys. 4, 130 (2008).
*** B. Shepherd and J. Clarke, Proc. EPAC 2006, 3580 (2006).

Slides

• N. Chauvin, R.D. Duperrier, A. Mosnier, P.A.P. Nghiem, D. Uriot
  CEA, Gif-sur-Yvette

The 250 mA, 40 MeV cw deuteron beam required for the International Fusion Materials Irradiation Facility (IFMIF) will be provided by two 125 mA linacs. In order to accelerate the beam from 5 MeV to 40 MeV, a superconducting linac, housed in four cryomodules, is proposed. The design is based on two beta families (beta=0.094 and beta=0.166) of half-wave resonators (HWR) at 175 MHz. The transverse focusing is achieved using one solenoid coil per lattice. This paper presents the extensive multi-particle beam dynamics simulations that have been performed to adapt the beam along the SC-HWR structure in such a high space charge regime. As one of the constraints of the IFMIF linac is hands-on maintenance, specific optimizations have been done to minimize the beam occupancy in the line (halo). A Monte Carlo error analysis has also been carried out to study the effects of misalignments or field imperfections.

• Y. Sun, R. Tomás, F. Zimmermann
  CERN, Geneva

Funding: This work was supported by the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" programme (CARE, contract number RII3-CT-2003-506395).

The use of crab cavities in the LHC may not only raise the luminosity, but it could also complicate the beam dynamics, e.g. crab cavities might not only cancel synchro-betatron resonances excited by the crossing angle but they could also excite new ones. In this paper, we use weak-strong beam-beam model to study the incoherent linear tune shift of the weak beam, for the crossing collision case and crab collision case with a finite crossing angle. The tune shift is also compared among the head-on collision, crossing collision and crab collision cases, both analytically and numerically.

• Y. Giboudot, A. Khan
  Brunel University, Middlesex
• T.R. Edgecock
  STFC/RAL, Chilton, Didcot, Oxon
• A. Wolski
  The University of Liverpool, Liverpool

The unconventional size and the possibility of transverse displacement of the magnets in the EMMA non-scaling FFAG motivates a careful study of particle behavior within the EMMA ring. The magnetic field map of the doublet cell is computed using a Finite Element Method solver; particle motion through the field can then be found by numerical integration, using (for example) OPERA, or ZGOUBI. However, by obtaining an analytical description of the magnetic field (by fitting a Fourier-Bessel series to the numerical data) and using a differential algebra code, such as COSY, to integrate the equations of motion, it is possible to produce a dynamical map in Taylor form. This has the advantage that, after once computing the dynamical map, multi-turn tracking is far more efficient than repeatedly performing numerical integrations. Also, the dynamical map is smaller (in terms of computer memory) than the full magnetic field map; this allows different configurations of the lattice, in terms of magnet positions, to be represented very easily using a set of dynamical maps, with interpolation between the coefficients in different maps*.

*yoel.giboudot@stfc.ac.uk

• L. Yang, D. Robin, F. Sannibale, C. Steier, W. Wan
  LBNL, Berkeley, California

Funding: Work supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

Multiobjective optimization has been used in many fields including accelerator related projects. Here we use it as a powerful tool for lattice design and optimization, which includes betatron functions, brightness.

• J. Beebe-Wang, A.K. Jain
  BNL, Upton, Long Island, New York

Funding: Work performed under the auspices of the US DOE.

The existence of multipolar components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. Therefore, the statistical properties of the non-linear fields are crucial for understanding the beam behavior and for achieving the superior performance in RHIC. In an earlier work*, the field quality analysis of the RHIC interaction regions (IR) was presented. Furthermore, a procedure for developing non-linear IR models constructed from measured multipolar data of RHIC IR magnets was described. However, the field quality in the regions outside of the RHIC IR regions had not yet been addressed. In this paper, we present the statistical analysis of multipolar components in the magnetic fields of the RHIC arc regions. The emphasis is on the lower order components, especially the sextupole in the arc dipole and the 12-pole in the quadrupole magnets, since they are shown to have the strongest effects on the beam stability. Finally, the inclusion of the measured multipolar components data of RHIC arc regions and their statistical properties into tracking models is discussed.

*J. Beebe-Wang and A. Jain, “Realistic Non-linear Model and Field Quality Analysis in RHIC Interaction Regions”, proc. of PAC 2007, page 4309-4311 (2007)

• U. Iriso, G. Benedetti, A. Olmos
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The ALBA Linac is a turn-key system able to produce 4 nC electron beams at 100 MeV beams with a normalized emittance below 30 mm*mrad. Beam position stability below 0.1 mm is measured using new BPM electronics. Thorough analysis are carried out to measure the beam emittance, energy and energy spread. This paper discusses the measurement techniques, analysis method, and results obtained during the Linac commissioning.

• B. Dehning, D. Bocian, T.T. Boehlen, E. Effinger, J. Emery, F. Follin, V. Grishin, E.B. Holzer, H. Ikeda, S. Jackson, D.K. Kramer, G. Kruk, P. Le Roux, J. Mariethoz, M. Misiowiec, L. Ponce, C. Roderick, M. Sapinski, M. Stockner, C. Zamantzas
  CERN, Geneva
• A. Priebe
  Poznań University of Technology, Poznań

The LHC beam loss monitoring system (BLM) consists of about 4000 monitors observing losses at all quadrupole magnets and many other likely loss locations. At the first LHC operation in August and September 2008 all monitors were active and used to observe the losses during the initial beam steerings, at collimators, at the LHC dump and during aperture scans. The different loss patterns will be discussed and compared with the expectations originating from simulations. The observed signals of the BLM system will be analysed in terms of response time, sensitivity cross talk between channels and noise performance.

• R.J. Steinhagen, A. Boccardi, E. Calvo Giraldo, M. Gasior, J.L. Gonzalez, O.R. Jones
  CERN, Geneva

Until now, the continuous monitoring of the LHC lattice has been considered as impractical due to tight constraints on the maximum allowed beam excitations and acquisition time usually required for betatron function measurements. As an further exploitation of the Base-Band-Tune (BBQ) detection principle, already widely used for tune diagnostic, a real-time beta-beat measurement prototype has been successfully tested at the CERN SPS based on the continuous measurement of the cell-to-cell betatron phase advance. Tests show that the phase resolutions is better than a degree corresponding to a peak-to-peak beta-beat resolution of about one percent. Due to the system's high sensitivity it required only micro-metre range excitation, making it compatible with nominal LHC operation. This contribution discusses results, measurement systematics and possible additional exploitation that may be used to improve the nominal LHC performance.

• E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar
  CERN, Geneva

Diagnostic techniques based on the Schottky spectrum of the peak detected signal have been used at CERN for a long time to study the behaviour of bunched beams. In this paper it is shown how the measured spectrum is related to the particle distribution in synchrotron frequency. The experimental set-up used and its limitations are also presented together with examples of beam measurements in the SPS and LHC.

• N. Barov, J.S. Kim, D.J. Newsham
  Far-Tech, Inc., San Diego, California

The emittance exchange experiment planned at the Argonne Wakefiel Accelerator facility will rely on a set of cavity-based beam diagnostics in order to map the transport matrix through the beamline. These will include cavity BPM and time-of-flight diagnostics, as well as quadrupole cavity x-y coupling diagnostics. The measurement system will be designed to fit within compact space requirements, while also maintaining a sufficient clear aperture and sensitivity. The RF design of the system, as well as RF cold-test data for the BPM cavities, is presented.

• C.-Y. Tan, K.L. Duel, R.M. Zwaska
  Fermilab, Batavia

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.

We have designed a retarding field analyzer (RFA) and a rad-hard amplifier which improves the sensitivity over the present RFA installed in the Main Injector. From computer simulations and bench measurements, our RFA will have a 20% improvement in sensitivity compared to the Argonne National Laboratory (ANL) design. And when we couple our RFA to the matched rad-hard amplifier, S/N is also improved.

• G.M. Kazakevich, M.A. Davidsaver, H.T. Edwards, R.P. Fliller, T.W. Koeth, A.H. Lumpkin, S. Nagaitsev, J. Ruan, R. Thurman-Keup
  Fermilab, Batavia
• Y.U. Jeong
  KAERI, Daejon
• V.V. Kubarev
  BINP SB RAS, Novosibirsk

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.

Noninvasive bunch duration monitoring has a crucial importance for modern accelerators intended for short wavelength FEL’s, colliders and in some beam dynamics experiments. Monitoring of the bunch compression in the Emittance Exchange Experiment at the A0 Photoinjector was done using a parametric presentation of the bunch duration via Coherent Synchrotron Radiation (CSR) emitted in a dipole magnet and measured with a wide-band quasi-optical Schottky Barrier Detector (SBD). The monitoring resulted in a mapping of the quadrupole parameters allowing a determination of the region of highest compression of the bunch in the sub-picosecond range. The obtained data were compared with those measured using the streak camera. A description of the technique and the results of simulations and measurements are presented and discussed in this report.

• A. Faus-Golfe, C. Blanch Gutierrez, J.V. Civera-Navarrete, J.J. García-Garrigós
  IFIC, Valencia

Funding: FPA 2007-31124-E (MICINN)

A set of two Inductive Pick-Up (IPU) prototypes with its associated electronics for Beam Position Monitoring in Test Beam Line (TBL) in the 3rd CLIC Test Facility (CTF3) at CERN were designed, constructed, characterized and tested by the IFIC. One of these two prototypes is already mounted in the first module of the TBL line for testing with beam. In the first part of this paper we described the first tests performed with beam in the prototype. The second part of this paper is dedicated to the description of the construction, performance characterization and installation of a series of 15 units, including its respective mechanical supports in the complete TBL line in spring 2009.

• K. Artoos, O. Capatina, C.G.R.L. Collette, M. Guinchard, C. Hauviller, F. Lackner, J. Pfingstner, H. Schmickler, M.V. Sylte
  CERN, Geneva
• B. Bolzon, L. Brunetti, G. Deleglise, N. Geffroy, A. Jeremie
  IN2P3-LAPP, Annecy-le-Vieux
• P.A. Coe, D. Urner
  OXFORDphysics, Oxford, Oxon
• M. Fontaine
  CEA, Gif-sur-Yvette

To reach the design luminosity of CLIC, the movements of the quadrupoles should be limited to the nanometer level in order to limit the beam size and emittance growth. Below 1 Hz, the movements of the main beam quadrupoles will be corrected by a beam-based feedback. But above 1 Hz, the quadrupoles should be mechanically stabilized. A collaboration effort is ongoing between several institutes to study the feasibility of the “nano-stabilization” of the CLIC quadrupoles. The study described in this paper covers the characterization of independent measuring techniques including optical methods to detect nanometer sized displacements and analyze the vibrations. Actuators and feedback algorithms for sub-nanometer movements of magnets with a mass of more than 400 kg are being developed and tested. Input is given to the design of the quadrupole magnets, the supports and alignment system in order to limit the amplification of the vibration sources at resonant frequencies. A full scale mock-up integrating all these features is presently under design. Finally, a series of experiments in accelerator environments should demonstrate the feasibility of the nanometer stabilization.

• M. Masuzawa, Y. Ohsawa, N. Ohuchi
  KEK, Ibaraki

KEKB is a double-ring collider with a circumference of 3016 m. The two rings were built side-by-side in the TRISTAN tunnel, 11 m below ground. KEKB has been operating successfully for about 10 years, since 1999, and its peak luminosity continues to improve. During the summer shutdown of 2008, the magnet tilts were measured for the first time since installation and it was found that some magnets were rotated over time. The tunnel level marker and the magnet height were also surveyed. The south region of the tunnel is sinking, resulting in magnet level changes. The survey results will be reported in this paper.

• B. Bolzon, A. Jeremie
  IN2P3-LAPP, Annecy-le-Vieux
• P. Bambade
  KEK, Ibaraki
• Y. Renier
  LAL, Orsay
• A. Seryi
  SLAC, Menlo Park, California

Funding: Work supported by the Agence Nationale de la Recherche of the French Ministry of Research (Programme Blanc, Project ATF2-IN2P3-KEK, contract ANR-06-BLAN-0027).

CLIC is one of the current projects of linear colliders. Achieving a vertical beam size of 1 nm at the Interaction Point (IP) with several nanometers of fast ground motion imposes an active stabilization of final doublet magnets (FD) at a tenth of nm above 4Hz. ATF2 is a test facility for linear colliders whose first aim is to have a vertical beam size of 37nm. Relative motion tolerance between FD and the IP is of 7nm above 0.1Hz. Because ground motion is coherent between these two elements, they were fixed to the floor so that they move in a coherent way. Investigations are going on to have in 2011 a useful active stabilization for ATF2 in order to use it as a CLIC prototype. Parameters of a 2D ground motion generator were fitted on measurements to reproduce spatial and temporal spectra, so it can be used for ATF2 simulations. Thus, we evaluated the ideal response function that an active stabilization FD system would need to have to improve on the present ATF2 system. Because ground motion coherence is lost with upstream magnets, we simulated the integrated vibrations at the IP to evaluate the usefulness of their stabilization. These results were validated with measurements.

• F. Hellberg, H. Danared, A. Hedqvist
  MSL, Stockholm
• J. Pflüger
  DESY, Hamburg

The undulators of the European free-electron laser (XFEL) are 128 to 226 meters in length and divided into five meter long segments. Each segment ends with a quadrupole magnet to focus the electron beam and to maintain optimum spatial overlap between the electron and photon beams. At the Manne Siegbahn Laboratory a rotating coil instrument has been built to characterize these quadrupoles and to measure the position of the magnetic center. In combination with a coordinate measurement machine the magnetic center can be measured with respect to fiducials on the magnet. The aim is to measure the position of the magnetic center within 0.050 mm. In this work the experimental setup is presented together with fiducialization of test magnets.

• A. Aksoy, O. Yavas
  Ankara University, Faculty of Engineering, Tandogan, Ankara
• D. Schulte
  CERN, Geneva

Funding: Turkish Atomic Energy Authority

CLIC study aims at a center-of-mass energy for electron-positron collisions of 3TeV using room temperature accelerating structures at high frequency (12GHz) which are likely to achieve 100 MV/m gradient. Due to conventional high frequency RF sources do not provide sufficient RF power for 100MV/m gradient, CLIC relies upon a two-beam-acceleration concept: The 12GHz RF power is generated by a high current electron beam (Drive Beam) running parallel to the main beam with deceleration in special Power Extraction Structures (PETS) and the generated RF power is transferred to the main beam. In order to obtain very high RF power at 12GHz frequency, injected beam into PETS should have 2.37GeV energy, 101A pulse current and pulse length around 240ns. Drive beam accelerator (DBA) accelerates the beam up to 2.37GeV in almost fully-loaded structures and the pulse after DBA contains more than 70000 bunches, has a length around 140μs and 4.2A pulse current. After some modifications in delay loop and in combiner rings the beam has 101A pulse current and 240ns pulse length. In this study simulations of some transverse beam parameters for different options for the lattice of the DBA are presented.

• K. Zengin
  Ankara University, Faculty of Sciences, Tandogan/Ankara

The Turkish Accelerator Complex (TAC) is a project for accelerator based fundamental and applied researches supported by Turkish State Planning Organization (DPT). The proposed complex is consisted of 1 GeV electron linac and 3.56 GeV positron ring for a charm factory and a few GeV proton linac. Apart from the particle factory, it is also planned to produce synchrotron radiation from positron ring. In this study the lattice structure design of the positron storage ring is made to produce the third generation synchroton light. It has been studied with different lattice structures (DBA, TBA, DDBA etc.) for TAC. It has been compared lattice structures and tried to find the best structure for lowest emittance.

• V. Sajaev
  ANL, Argonne

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

An energy recovery linac (ERL) is one of the candidates for an upgrade of the Advanced Photon Source (APS). In addition to the APS ring and full-energy linac, our design also includes a large turn-around arc that could accommodate new x-ray beamlines as well. In total, the beam trajectory length would be close to 3 km. The ERL lattice has strong focusing to limit emittance growth, and it includes strong sextupoles to keep beam energy spread under control and minimize beam losses. As in storage rings, trajectory errors in sextupoles will result in lattice perturbations that would affect delivered x-ray beam properties. In storage rings, the response matrix fit method is widely used to measure and correct linear lattice errors. Here, we explore the application of the method to the linear lattice correction and coupling correction of an ERL.

• R.T. Dowd, M.J. Boland, G. LeBlanc, Y.E. Tan
  ASCo, Clayton, Victoria

Emittance coupling in the Australian Synchrotron storage ring is currently controlled using a total of 28 skew quadrupoles. The LOCO method was used to calculate the skew quadrupole settings, using measured vertical dispersion and transverse coupling. This information is used to create a calibrated model of the machine, which is then used to calculate the required skew quadrupole settings needed to minimise coupling. This method has thus far achieved encouraging results for achieving ultra low (<2pm) vertical emittance. In this study we seek to explore the validity of the LOCO model based on empirical measurements and possible improvements of this method.

• Y.E. Tan, D.R.T. Appadoo, M.J. Boland, R.T. Dowd
  ASCo, Clayton, Victoria

Generating short bunches for time resolved studies or the generation of THz radiation has been done at many other light sources and is of increasing interest in the user community. Light sources not designed with ps bunchs can usually tune the lattice to reduce ps bunchs without much difficulty, sometimes referred to as a Low Alpha mode. At the Australian light source a low alpha configuration has been investigated. The results looking into the 'shaping' of the momentum compaction factor, beam stability and current limitations will be presented.

• L. Liu, R.H.A. Farias, X.R. Resende, P.F. Tavares
  LNLS, Campinas

The UVX electron storage ring at the Brazilian Synchrotron Light Laboratory (LNLS) was recently equipped with active current shunt circuits that allow for individual variation of the quadrupole magnet strengths. This allows us to apply the widely used technique of beam-based alignment (BBA) to calibrate the electrical center offset of the BPMs with respect to the magnetic center of the closest quadrupole. In this report we present the BBA experimental results and an analysis of the resolution of the method in the case of the LNLS UVX storage ring.

• X.R. Resende, R.H.A. Farias, L. Liu, M.B. Plotegher, P.F. Tavares
  LNLS, Campinas

The synchrotron machine at the Brazilian Synchrotron Light Laboratory (LNLS) is a storage ring for 1.37 GeV electrons composed of six DBA cells whose lengths add up to around 93 meters of circumference. There are 18 horizontal and 24 vertical correctors available in the ring for correcting the orbit as measured at 24 BPMs. In the past, stored beams have been delivered which successfully fulfilled user’s stability and emittance demands. This has been accomplished by fine tuning the machine using mostly measured beam parameters. The ongoing commissioning of the a new undulator beamline, which is expected to become the most demanding one, puts pressure in the direction of improving existing models of the ring optics in order to envisage ways of improving beam quality. In this paper we discuss preliminary tests with LOCO* at the LNLS. We report on the impact of the calibration of the machine based on LOCO calculations through the analysis of standard experiments and optics parameters such as beta-beat reduction, improvement of life-time and so on.

*LOCO in the Beam Dynamics Newsletter, 44, ICFA, December 2007.

• K.A. Brown, L. A. Ahrens, R. Bonati, D.M. Gassner, J.W. Glenn, H. Huang, J. Morris, S.M. Nida, V. Schoefer, N. Tsoupas, K. Zeno
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

The Booster to AGS (BtA) transfer line was designed to match both ions and protons into the AGS lattice. For proton beam operation the only constraint on the optics is to define a match to the AGS lattice. For ions operation there are constraints introduced by a stripping foil in the upstream part of the transfer line. For polarized proton operation there is the complication that the lattice to match into in the AGS is distorted by the presence of two partial snake magnets. In the 2008 polarized proton run it was observed that there was an optical injection mismatch. Beam experiments were conducted that showed disagreement with the model. In addition, these studies revealed some minor problems with the instrumentation in the line. A new model and more reliable measurements of the transfer line magnet currents have been implemented. Another series of experiments were conducted to test these modifications and to collect a more complete set of data to allow better understanding of the beam dynamics during the transfer and better understanding of the instrumentation. In this paper we will present the results of these experiments and comparison to the new model of the BtA.

• Y. Li, S. Krinsky, M. Rehak
  BNL, Upton, Long Island, New York

Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886

In this paper, we discuss an algorithm for constructing a numerical linear optics model for dipole magnets from a 3D field map. The difference between the numerical model and K. Brown’s analytic approach is investigated and clarified. It was found that the optics distortion due to the dipoles’ fringe focusing must be properly taken into account to accurately determine the chromaticities. In NSLS-II, there are normal dipoles with 35-mm gap and dipoles for infrared sources with 90-mm gap. This linear model of the dipole magnets is applied to the NSLS-II lattice design to match optics parameters between the DBA cells having dipoles with different gaps.

• S. Bai, J. Gao, X.W. Zhu
  IHEP Beijing, Beijing
• A.S. Aryshev
  JAI, Egham, Surrey
• P. Bambade, T. Okugi
  KEK, Ibaraki
• Y. Kamiya
  ICEPP, Tokyo
• D.J. McCormick, M. Woodley
  SLAC, Menlo Park, California
• M. Oroku, T. Yamanaka
  University of Tokyo, Tokyo

Funding: NSFC 10525525 and 10775154. CNRS-IN2P3 and ANR.

The ATF2 project is the final focus system prototype for ILC and CLIC linear collider projects, with a purpose to reach a 37nm vertical beam size at the interaction point. We report on techniques developed based on simulation studies to adjust the horizontal and vertical beam waists independently in the presence of errors, at two different IP locations where the beam size can be measured with different accuracies. During initial commissioning, we will start with larger than nominal β-functions at the IP, to reduce the effects from higher-order optical aberrations and thereby simplify the optical corrections needed. The first measurements in such intermediate β-configurations are reported.

• D. Wang, J. Gao
  IHEP Beijing, Beijing
• D. Schulte, F. Stulle
  CERN, Geneva

A new design of the 6.6GeV Booster linac for CLIC which is based on the FODO lattice is presented in this note. Particle tracking studies using PLACET [1] are performed in order to estimate the single-bunch and multi-bunch emittance growth. First, the studies of optics are introduced. Then, the sing-bunch effects and multi-bunch effects are studied in the last two part of this note.

• G. Benedetti, D. Einfeld, J. Marcos, M. Muñoz, M. Pont
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The ALBA booster is a 100 MeV-3 GeV ramping synchrotron, with large circumference of 249.6 m and low emittance of 9nm*rad, cycling at 3 Hz. The lattice consists of a 4-fold symmetric modified FODO lattice with defocusing gradient dipoles. Magnetic measurements on all magnets have been performed: the studies and lattice settings to recover the design optics preserving good machine performances, such as the lattice flexibility, the low beta functions and large dynamic aperture at high chromaticities, are presented.

• J.R. Thompson, G.H. Hoffstaetter
  CLASSE, Ithaca, New York

The production of ultra-short x-rays in Cornell's Energy Recovery Linac (ERL) requires electron bunch lengths of less than 100fs with minimal transverse emittance growth and energy spread. Because the linac consists of two sections separated by an arc, CSR forces limit the bunch length in the linac, and bunch compression has to be installed after acceleration. Creation of such short bunches requires a second order bunch compression scheme with correction of the third order dispersion. In this paper, we discuss possible bunch compression systems and explore the benefits of each using the tracking program TAO including CSR forces. Overall, we find that a FODO compressor utilizing dipole, quadrupole and sextupole magnets can achieve the design goals of the short pulse mode.

• V. Balandin, N. Golubeva
  DESY, Hamburg

The aim of the FLASH facility linac is to create electron bunches of small transverse emittance and high current for the FLASH free-electron laser at DESY. Available operational experience indicates that in order to optimize SASE signal at different wavelengths or to fine-tune the FEL wavelength, empirical adjustment of the machine parameters is required and, therefore, the sensitivity of the beamline to small changes in the beam energy and in the magnet settings becomes one of the important issues which affects the final performance. In this article the transverse optics of the FLASH beamline with low sensitivity to changes in beam energy and quadrupole settings is presented. This optics is in operation since spring 2006 and has shown a superior performance with respect to the previous setup of the transverse focusing.

• B. Singh, R.T. Fielder, E.C. Longhi, I.P.S. Martin, C. Rau, U.H. Wagner
  Diamond, Oxfordshire
• R. Bartolini
  JAI, Oxford

A proposal has been developed to modify a long insertion straight (~11.4 m long) of the DIAMOND storage ring. Additional quadrupoles provide two sections with small vertical beta-function values, in order to accommodate two canted in-vacuum undulators for the imaging and coherence branches of the I13 beam line. A further requirement was to provide a horizontal focussing of the emitted undulator radiation by means of a positive alpha-x in the second section. This optic is obtained using a small relaxation in the “pi–trick”, approximately preserving the on-momentum nonlinear dynamics of the ring. The effects of the optic on beam dynamics (i.e. beam lifetime, injection etc.) and possible compensation schemes are presented.

• C. Carli, M. Aiba, M. Chanel, B. Goddard, M. Martini, W.J.M. Weterings
  CERN, Geneva

The motivation for the construction of CERN Linac4 is to improve the performance of the PSB by raising the injection energy and implementing a new H^- charge exchange multiturn injection scheme. Strategies to design the H^- charge exchange injection hardware and, in particular, to mitigate perturbations of the lattice will be reported and the proposed geometry described.

• S.D. Fartoukh
  CERN, Geneva

As for the final focus systems of linear colliders, the chromatic aberrations induced by low-beta insertions can seriously limit the performance of circular colliders. The impact is two-fold: (1) a substantial off-momentum beta-beating wave travelling all around of the ring leading to a net reduction of the mechanical aperture of the low-beta quadrupoles but also impacting on the hierarchy of the collimator and protection devices of the machine, (2) a huge non-linear chromaticity, essentially Q’’ and Q’’’, which, when combined with the geometric non-linear imperfection of the machine could substantially reduce the momentum acceptance of the ring by sending slightly off-momentum particles towards non-linear resonances. These effects will be analyzed and illustrated in the framework of the LHC insertions upgrade and a strategy for correction will be developed, requiring a deep modification of the LHC overall optics.

• K. Fuchsberger, S.D. Fartoukh, B. Goddard, O.R. Jones, V. Kain, M. Meddahi, V. Mertens, J. Wenninger
  CERN, Geneva

The 3 km long TI 8 transfer line is used to transfer 450 GeV proton and ion beams from the SPS to LHC collider. As part of a detailed optics investigation program the chromaticity of the transfer line was measured. Kick response data of the transfer line was recorded for various extraction energy offsets in the SPS. The quadrupolar and sextupolar field errors over the whole transfer line dipoles, a systematic error of the main quadrupole strengths and the initial momentum error were estimated by a fit. Using the updated model, the chromaticity of the line was then calculated.

• M. Meddahi, I.V. Agapov, K. Fuchsberger, B. Goddard, W. Herr, V. Kain, V. Mertens, D.P. Missiaen, T. Risselada, J.A. Uythoven, J. Wenninger
  CERN, Geneva
• E. Gianfelice-Wendt
  Fermilab, Batavia

Funding: Work partly supported by Fermilab, operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy

Through May to September 2008, further beam commissioning of the SPS to LHC transfer lines was performed. For the first time, optics and dispersion measurements were also taken in the last part of the lines, and into the LHC. Extensive trajectory and optics studies were conducted, in parallel with hardware checks. In particular dispersion measurements and their comparison with the beam line model were analysed in detail and led to propose the addition of a “dispersion-free” steering algorithm in the existing trajectory correction program.

• C. Heßler, M. Eshraqi, B. Goddard, A.M. Lombardi, M. Meddahi
  CERN, Geneva

The proposed new CERN injector chain LINAC4, SPL, PS2 will require the construction of new beam transfer lines. A preliminary design has been performed for the 4 GeV SPL to PS2 H^- transfer line. The constraints, beam parameters and geometry requirements are summarised and a possible layout proposed, together with the magnet specifications. First considerations on longitudinal beam dynamics and on beam loss limitations from H^- lifetime are presented.

• Y. Papaphilippou, J. Barranco, W. Bartmann, M. Benedikt, C. Carli
  CERN, Geneva
• R. De Maria, S. Peggs, D. Trbojevic
  BNL, Upton, Long Island, New York

The effect of magnet misalignments in the beam orbit and linear optics functions are reviewed and correction schemes are applied to the negative momentum compaction lattices of PS2. Chromaticity correction schemes are also proposed and tested with respect to off-momentum optics properties. The impact of the correction schemes in the dynamic aperture of the different lattices is finally evaluated.

• Y. Papaphilippou, J. Barranco, W. Bartmann, M. Benedikt, C. Carli, B. Goddard
  CERN, Geneva
• R. De Maria, S. Peggs, D. Trbojevic
  BNL, Upton, Long Island, New York

In view of the CERN Proton Synchrotron proposed replacement with a new ring (PS2), a detailed optics design as been undertaken following the evaluation of several lattice options. The basic arc module consists of cells providing negative momentum compaction. The straight section is formed with a combination of FODO and quadrupole triplet cells, to accommodate the injection and extraction systems, in particular the H^- injection elements. The arc is matched to the straight section with a dispersion suppressor and matching module. Different lattices are compared with respect to their linear optics functions, tuning flexibility and geometrical acceptance properties.

• D. Schulte
  CERN, Geneva

In the main linac of the compact linear collider (CLIC) the beam induced wakefield and dispersive effects will be strong. In the paper the reference beam-based alignment procedure for the new CLIC parameters is specified and the resulting tolerances for static imperfections are detailed.

• D. Schulte, R. Tomás
  CERN, Geneva

In the compact linear collider (CLIC) the tolerances on dynamic imperfections are tight in the main linac. In particular the limited beam delivery system bandwidth requires very good RF phase and amplitude stability. Transverse motion of the beam line components is also of concern. The resulting tolerances are detailed in the paper.

• Y. Alexahin, E. Gianfelice-Wendt
  Fermilab, Batavia

Funding: Work supported by Fermilab, operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy

Recent advances in the HTS magnet technology and ionization cooling theory have re-launched the interest of the physics community in the realization of a high energy, high luminosity Muon Collider (MC). The large muon energy spread requires large momentum acceptance and the required luminosity calls for beta* in the mm range. To avoid luminosity degradation due to the hour-glass effect, the bunch length must be comparatively small. To keep the needed RF voltage inside feasible limits the momentum compaction factor must be as small as possible. Under these circumstances chromatic effects correction, energy acceptance, dynamic aperture and longitudinal motion stability are main issues of a MC design. In this paper we give an overview of various lattice designs toward a high luminosity, large energy acceptance MC currently under study at Fermilab.

• Y. Alexahin, E. Gianfelice-Wendt
  Fermilab, Batavia

Funding: Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.

Muon collider is a promising candidate for the next energy frontier machine. In order to obtain peak luminosity of the order of 10³5/cm²/s in the TeV energy range the beta function at the interaction point should be smaller than 1cm. To obtain correspondingly small bunch length with a reasonable RF voltage (within 1GV) the momentum compaction factor should be smaller than 10^-4 in the momentum range ~1%. The lattice design must also provide sufficient dynamic aperture for ~20 microns normalized beam emittance and minimum possible circumference. Together these requirements present a challenge which has never been met before. We offer a solution to this problem which has the following distinctive features: i) chromatic compensation achieved with sextupoles and dispersion generating dipoles placed near the IR quadrupoles (not in a special section), ii) low value of momentum compaction factor obtained by balancing positive contribution from the arcs with negative contribution from the suppressors of the generated in the IR dispersion. Theoretical aspects and various options will be discussed.

• M. Apollonio
  Imperial College of Science and Technology, Department of Physics, London

The Muon Ionisation Cooling Experiment (MICE) at RAL will be the first apparatus to study muon cooling at high precision. Muons are produced along a transport beamline in a super-conducting solenoid via pion decay. The final beam emittance is generated by tuning the quadrupoles for beam size matching. The beam angular divergence is matched in a variable-thickness diffuser, which is a re-entrant mechanism inside the first solenoid, automatically changeable in few minutes from 0 to 4X0. The initial normalized emittance of the beam (few mm rad) will be inflated up to 10 mm rad in order to cover the (e_N,P) matrix required by the experiment. Details of beamline tuning are presented.

• Z. Liu
  IUCF, Bloomington, Indiana
• S.M. Cousineau, J.A. Holmes, M.A. Plum
  ORNL, Oak Ridge, Tennessee

Funding: Division of Materials Science, U.S. Department of Energy, under contract number DE-AC05-96OR22464 with UT-Battelle Corporation for Oak Ridge National Laboratory

In order to achieve a more robust and optimal performance, the difference between the real machine and its underlying model should be understood and eliminated. Discrepancies between the measuremed and predicted linear optics suggest possible errors of the focusing magnets and diagnostic devices. To find and correct those errors, a widely used method, orbit response matrix (ORM)* approach is applied to the SNS storage ring, which successfully brings the tune deviation from 3% to 0.1%, improves horizontal beta beating from 15% to 3%, and perfectly flattens the orbit. In this article, we discussed the progress and possible future improvements with the SNS ring optics correction.

*J. Safranek, "Experimental determination of storage ring optics using closed orbit response measurements", Nucl. Inst. and Meth. A388, (1997), pg. 27

• B. Nash, W. Guo
  BNL, Upton, Long Island, New York

Successful operation of NSLS-II requires sufficient dynamic aperture for injection, as well as momentum aperture for Touschek lifetime. We explore the dependence of momentum and dynamic aperture on higher-order multipole field errors in the quadrupoles and sextupoles. We add random and systematic multipole errors to the quadrupoles and sextupoles and compute the effect on dynamic aperture. We find that the strongest effect is at negative momentum, due to larger closed orbit excursions. Adding all the errors based on the NSLS-II specifications, we find adequate dynamic and momentum aperture.

• G. Wang, M. Bai, V. Litvinenko, T. Satogata
  BNL, Upton, Long Island, New York

Funding: Department of Energy

Precise measurements of optics from coherent betatron oscillations driven by ac dipoles have been demonstrated at RHIC and the Tevatron. For RHIC, the observed rms beta-beat is about 10%. Reduction of beta-beating is an essential component of performance optimization at high energy colliders. A scheme of optics correction was developed and tested in the RHIC 2008 run, using ac dipole optics for measurement and a few adjustable trim quadrupoles for correction. In this scheme, we first calculate the phase response matrix from the measured phase advance, and then apply a singular value decomposition (SVD) algorithm to the phase response matrix to find correction quadrupole strengths. We present both simulation and some preliminary experimental results of this correction.

• M. Muñoz, D. Einfeld, Z. Martí
  CELLS-ALBA Synchrotron, Cerdanyola del Vallès

The Spanish synchrotron light source ALBA is in the process of installation, with the large majority of components already manufactured and delivered. Among them, the magnets of the storage ring. As part of the acceptance process of the magnets, a campaign to measure the quality of them (magnetic length, effective bending and focusing, high order multipolar components) has been performed in-house and in the manufacturer. The results of this measures have been applied to the model of the storage ring, analyzing the effects in the performance (lifetime, dynamic aperture, orbit, etc). The results of the study confirm the quality of the magnet's design and manufacturing as well as the performance of the lattice.

• G.H. Gillespie, W. Hill
  G.H. Gillespie Associates, Inc., Del Mar, California
• J.F. DeFord, B. Held
  STAAR/AWR Corporation, Mequon

Funding: Work at G. H. Gillespie Associates, Inc. funded by the U.S. Department of Energy SBIR grant number DE-FG02-05ER84360

An automated procedure for the calculation of particle transfer maps using computed magnetic field data has been developed for several types of magnetic quadrupoles. The Automated Transfer Map Generator (ATMG) software used for these calculations combines the Analyst program and specialized modules of the Particle Beam Optics Laboratory (PBO Lab). Analyst's scripted solids capability is used to develop models of different magnet concepts. The geometry and material attributes for a given magnet concept are encapsulated by a small number of magnet parameters. Quadrupoles of the same basic concept can be simulated by using different values for the magnet parameters. The three-dimensional magnetic field solver (MS3p) of the Analyst program is used to obtain the fields. New PBO Lab modules are used to automate the field computation, and then calculate the transfer maps and matrices through third-order using the Venturini-Dragt method. Examples for three different types of magnetic quadrupole lenses are presented: electromagnetic air-core, electromagnetic iron-core, and rare-earth permanent magnet quadrupoles.

• A. Dolinskyy, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, C. Peschke, M. Steck
  GSI, Darmstadt

The FAIR Storage Rings (CR, RESR and NESR) are designed for efficient cooling, accumulation, deceleration and performing nuclear physics experiments with antiproton and rare isotopes beams. Tracking studies for all these rings have been performed to estimate the dynamic aperture and other properties of beam stability depending on the low and high field multipole components, fringe fields and field interference. The multipole limits have to be determined in order to provide a reasonable estimate of the stability boundary and needed correction of the low field multipoles. We report on quantitative studies of the effects of multipoles on the dynamic aperture of the rings, and show that the systematic multipole components in the present magnet designs are unlikely to impose a severe limitation.

• Y. Zhang, C.K. Allen, J. Galambos, J.A. Holmes, J. G. Wang
  ORNL, Oak Ridge, Tennessee

Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.

The Spallation Neutron Source (SNS) linac system is designed to deliver 1 GeV pulsed H^- beams up to 1.56 MW for neutron production. As beam power was increased from 10 kW to 660 kW in less than three years, beam loss in the accelerator systems – particularly in the superconducting linac (SCL), became more significant. In the previous studies, unexpected beam loss in the SCL was mainly attributed to longitudinal problems. However, our most recent simulations have focused on beam transverse effects. These include multipole components from magnet imperfections and dipole corrector windings of the linac quadrupoles. The effect of these multipoles coupled with other errors will be discussed.

• M. Dorf, R.C. Davidson, H. Qin, E. Startsev
  PPPL, Princeton, New Jersey

Funding: Research supported by the U.S. Department of Energy.

This paper reports on recent advances in the development of a numerical scheme for describing the quiescent loading of a quasi-equilibrium beam distribution matched to a periodic focusing lattice*. The scheme allows for matched-beam distribution formation by means of the adiabatic turn-on of the oscillating focusing field, and it is examined here for the cases of alternating-gradient quadrupole and periodic solenoidal lattices. Furthermore, various distributions are considered for the initial beam equilibrium. The self-similar evolution of the matched-beam density profile is observed for arbitrary choice of initial distribution function and lattice type. The numerical simulations are performed using the WARP particle-in-cell code.

* M.Dorf et al., Phys. Rev. ST Accel. Beams, submitted for publication(2009).

• H. Qin, R.C. Davidson
  PPPL, Princeton, New Jersey

Funding: Supported by the U.S. Department of Energy.

Courant-Snyder (CS) theory is generalized to the case of coupled transverse dynamics with two degree of freedom. The generalized theory has the same structure as the original CS theory for one degree of freedom. The four basic components of the original CS theory, i.e., the envelope equation, phase advance, transfer matrix, and the CS invariant, all have their counterparts, with remarkably similar formal expressions, in the generalized theory presented here. The unique feature of the generalized CS theory is the non-commutative nature of the theory. In the generalized theory, the envelope function is generalized into an envelope matrix, and the envelope equation becomes a matrix envelope equation with matrix operations that are not commutative. The generalized theory gives a new parameterization of the 4D symplectic transfer matrix that has the same structure as the parameterization of the 2D symplectic transfer matrix in the original CS theory.

• P.A. Piminov, A.V. Bogomyagkov, E.B. Levichev
  BINP SB RAS, Novosibirsk
• M.E. Biagini, P. Raimondi, M. Zobov
  INFN/LNF, Frascati (Roma)

A project of the SuperB Factory in Italy with the crab-waist collision scheme and extremely large luminosity addresses new challenges to the nonlinear beam dynamics study. Among these challenges are: low emittance lattice requiring strong sextupoles for chromatic correction, sub-mm vertical betatron function at the IP, crab sextupoles placed at both sides from the IP, etc. In this report we describe the results of the DA limiting sources analysis and optimization of the arrangement of the IR and Crab sextupoles and octupoles for the Low Energy Ring (LER).

• M.-A. Tordeux, P. Brunelle, A. Loulergue, A. Nadji, L.S. Nadolski
  SOLEIL, Gif-sur-Yvette

SOLEIL, the French 2.75 GeV third generation synchrotron light source, was commissioned 3 years ago. Thanks to beam-based measurements, the theoretical model of the storage ring lattice model has been improved. First, the quadrupole lengths in the hard edge model were finely tuned to get good agreement with the experimental measurements of betatron tunes for different optics. Second, the non-linear model was modified to better fit with beam-based on-momentum frequency map measurements. A thick sextupole model has been introduced in addition to the non-linear effect of the fringe field in quadrupoles. Simulated and measured tune shifts with transverse amplitudes are then compared. Finally a coupled machine model has been built thanks to crosstalk closed orbit acquisitions. A comparison with another model which is based on turn by turn beam position monitor data is presented. As a validation check, the coupling effect of the 10 m long HU640 undulator is evaluated through these coupled models.

• C.E. Mitchell
  UMD, College Park, Maryland

Funding: DOE grant DEFG02-96ER40949

Transfer maps for magnetic elements in storage and damping rings can depend sensitively on nonlinear fringe-field and high-order-multipole effects. The inclusion of these effects requires a detailed and realistic model of the interior and fringe magnetic fields, including their high spatial derivatives. A collection of surface fitting methods has been developed for extracting this information accurately from 3-dimensional magnetic field data on a grid, as provided by various 3-dimensional finite element field codes. The virtue of surface methods is that they exactly satisfy the Maxwell equations and are relatively insensitive to numerical noise in the data. These techniques can be used to compute, in Lie-algebraic form, realistic transfer maps for LHC final-focus quadrupoles and for the proposed ILC Damping Ring wigglers. An exactly-soluble but numerically challenging model field is used to provide a rigorous collection of performance benchmarks.

• Y. Lee, P.-A. Duperrex, D.C. Kiselev, U. Muller
  PSI, Villigen

The Paul Scherrer Institute (PSI) operates a high power proton accelerator for the research projects in physical and medical sciences. Currently, a proton beam current of 2mA with a beam power of 1.2MW is routinely used. In the future, the ring cyclotron with new cavities will make a proton beam current of 3mA possible. The enhanced beam power will generate higher thermal and mechanical loads to different accelerator components. In this paper, a simulation based study of a new current monitor designed to sustain the 3mA beam operation is presented. The monitor is located behind the second graphite target and exposed to scattered particles and their secondaries. The thermal energy deposition in the current monitor has been calculated by the Monte-Carlo particle transport code MARS. The calculated power source has been used for the the coupled flow, heat and radiation simulations, for the prediction of the operating temperature. The effect of the newly introduced water cooling system and the surface blackening has been analyzed by using CFX. The thermal properties of the monitor system have been measured by laboratory experiments, and a simulation validation study is presented.

• W.J. Corbett, W.X. Cheng, A.S. Fisher, E. Irish
  SLAC, Menlo Park, California
• T.M. Mitsuhashi
  KEK, Ibaraki
• W.Y. Mok
  Life Imaging Technology, Palo Alto, California

Funding: Work sponsored by U.S. Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.

A two-slit interferometer has been installed in the SPEAR3 diagnostic beam line to measure vertical beam size at a dipole source point. The diagnostic beam line accepts unfocused, visible light in a 3.5 x 6.0 mrad aperture so that at the slit location 17 m from the source, the vertical extent of the beam is 100mm. For typical source sizes of sigy~15 um (0.1% emittance coupling) a slit separation of 80 mm produces fringe visibility of order V=0.5. Hence a significant plot of fringe visibility vs. slit separation can be generated to infer source size via Fourier transformation. In this paper we report on the interferometer construction, beam size measurement and potential deficiencies of the system, and compare with theoretical results.

• J. Fang, P. Li, P. Lu, Q. Luo, B. Sun, X.H. Wang
  USTC/NSRL, Hefei, Anhui

The strip-line beam position monitor can be used as a non-intercepting emittance measurement monitor. The most important part of emittance measurement is to pick up the quadrupole component. To improve the accuracy of measurement, the response of the strip-line BPM pickups will be mapped before it’s installed in the HLS LINAC. This paper introduce the calibration system of the BPM, which consists of a movable antenna and a RF signal source, simulating the beam , a BPM moving bench with its control system, and an electronics system. When the position calibration is done first, the offset between electronic center and mechanical one of the BPM and the position sensitivity are gotten. There are two methods for quadrupole component calibration: one is indirect evaluation method that estimates the sensitivity of quadrupole component by the factor of position second moment; the other is direct method by simulation of a Gaussian beam through together many Gaussian weighted grid points. The results of two methods are given and compared. The effect of antenna’s diameter upon the fitting size of simulate beam has also been analyzed.

• A. Seryi, J.W. Amann, P. Bellomo, B. Lam, D.J. McCormick, J. Nelson, J.M. Paterson, M.T.F. Pivi, T.O. Raubenheimer, C.M. Spencer, M.-H. Wang, G.R. White, W. Wittmer, M. Woodley, Y.T. Yan, F. Zhou
  SLAC, Menlo Park, California
• D. Angal-Kalinin, J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• R. Apsimon, B. Constance, C. Perry, J. Resta-López, C. Swinson
  JAI, Oxford
• S. Araki, A.S. Aryshev, H. Hayano, Y. Honda, K. Kubo, T. Kume, S. Kuroda, M. Masuzawa, T. Naito, T. Okugi, R. Sugahara, T. Tauchi, N. Terunuma, J. Urakawa, K. Yokoya
  KEK, Ibaraki
• S. Bai, J. Gao
  IHEP Beijing, Beijing
• P. Bambade, Y. Renier, C. Rimbault
  LAL, Orsay
• G.A. Blair, S.T. Boogert, V. Karataev, S. Molloy
  Royal Holloway, University of London, Surrey
• B. Bolzon, N. Geffroy, A. Jeremie
  IN2P3-LAPP, Annecy-le-Vieux
• P. Burrows
  OXFORDphysics, Oxford, Oxon
• G.B. Christian
  ATOMKI, Debrecen
• J.-P. Delahaye, D. Schulte, R. Tomás, F. Zimmermann
  CERN, Geneva
• E. Elsen
  DESY, Hamburg
• E. Gianfelice-Wendt, M.C. Ross, M. Wendt
  Fermilab, Batavia
• A. Heo, E.-S. Kim, H.-S. Kim
  Kyungpook National University, Daegu
• J.Y. Huang, W.H. Hwang, S.H. Kim, Y.J. Park
  PAL, Pohang, Kyungbuk
• Y. Iwashita, T. Sugimoto
  Kyoto ICR, Uji, Kyoto
• Y. Kamiya
  ICEPP, Tokyo
• S. Komamiya, M. Oroku, T.S. Suehara, T. Yamanaka
  University of Tokyo, Tokyo
• A. Lyapin
  UCL, London
• B. Parker
  BNL, Upton, Long Island, New York
• T. Sanuki
  Tohoku University, Graduate School of Science, Sendai
• A. Scarfe
  UMAN, Manchester
• T. Takahashi
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima
• A. Wolski
  Cockcroft Institute, Warrington, Cheshire

ATF2 is a final-focus test beam line that attempts to focus the low-emittance beam from the ATF damping ring to a beam size of about 37 nm, and at the same time to demonstrate nm beam stability, using numerous advanced beam diagnostics and feedback tools. The construction is well advanced and beam commissioning of ATF2 has started in the second half of 2008. ATF2 is constructed and commissioned by ATF international collaborations with strong US, Asian and European participation.

Slides

• S. Bettoni, E. Adli, R. Corsini, A.E. Dabrowski, S. Döbert, D. Manglunki, P.K. Skowronski, F. Tecker
  CERN, Geneva

The aim of the last CLIC test facility CTF3, built at CERN by an international collaboration, is to prove the main feasibility issues of the CLIC two-beam acceleration technology. The main points which CTF3 should demonstrate by 2010 are the generation of a very high current drive beam and its use to efficiently produce and transfer RF power to high-gradient accelerating structures. To prove the first point a delay loop and a combiner ring have been built, following a linac, in order to multiply the current by a factor two and four, respectively. The power generation and transfer and the high gradient acceleration are instead demonstrated in the CLIC experimental area (CLEX), where the drive beam is decelerated in special power extraction structures(PETS). In this paper we describe the results of the combination in the ring, properly working after the cure of the vertical instability which limited high current operation, and the commissioning of the new beam lines installed in the second half of 2008, including response matrix analysis and dispersion measurements used to validate the optics model. The results of the energy transfer will be also briefly described.

Slides

• K. Kubo, S. Kuroda, T. Okugi
  KEK, Ibaraki
• K.G. Panagiotidis, A. Wolski
  The University of Liverpool, Liverpool
• M. Woodley
  SLAC, Menlo Park, California

One of the goals of the Accelerator Test Facility (ATF) at KEK is to demonstrate ultra-low vertical emittance for linear colliders. Highly precise correction of the vertical dispersion and betatron coupling will be needed to achieve the target of 2 pm (which will be required for ILC). Optics correction and tuning must be supported by an accurate model, which can be developed from a variety of beam measurements, including orbit response to dipole kicks, beta functions at the quadrupoles, etc. Here, we report experimental data and the status of the model and low-emittance tuning.

Slides

• M. Lamont, R. Alemany-Fernandez, R. Bailey, P. Collier, B. Goddard, V. Kain, A. Macpherson, L. Ponce, S. Redaelli, W. Venturini Delsolaro, J. Wenninger
  CERN, Geneva

A series of LHC injection tests was performed in August and September 2008. The first saw beam injected into sector 23; the second into sectors 78 and 23; the third into sectors 78-67 and sectors 23-34-45. The fourth, into sectors 23-34-45, was performed the evening before the extended injection test on the 10th September which saw both beams brought around the full circumference of the LHC. The tests enabled the testing and debugging of a number of critical control and hardware systems; testing and validation of instrumentation with beam for the first time; deployment, and validation of a number of measurement procedures. Beam based measurements revealed a number of machine configuration issues that were rapidly resolved. The tests were undoubtedly an essential precursor to the successful start of LHC beam commissioning. This paper provides an outline of preparation for the tests, the machine configuration and summarizes the measurements made and individual system performance.

Slides

• Y. Renier, P. Bambade
  LAL, Orsay
• B. Bolzon
  IN2P3-LAPP, Annecy-le-Vieux
• T. Okugi
  KEK, Ibaraki
• A. Scarfe
  UMAN, Manchester
• G.R. White
  SLAC, Menlo Park, California

Funding: CNRS/IN2P3 ANR (Programme Blanc, Project ATF2-IN2P3-KEK, contract ANR-06-BLAN-0027)

The orbit in the ATF2 extraction line has to be accurately controlled to allow orbit and optics corrections to work well downstream. The Final Focus section contains points with large beta function values which amplify incoming beam jitter, and few correctors since the steering is performed using quadrupole movers, and so good orbit stability is required. It is also essential because some magnets are non-linear and can introduce position-dependent coupling of the motion between the two transverse planes. First experience monitoring the orbit in the extraction line during the ATF2 commissioning is described, along with a simulation of the planned steering algorithm.

• C. Rimbault, P. Bambade
  LAL, Orsay
• S. Kuroda
  KEK, Ibaraki
• G.R. White, M. Woodley
  SLAC, Menlo Park, California

Funding: CNRS-IN2P3, ANR

The purpose of ATF2 is to deliver a beam with stable very small spotsizes as required for future linear colliders such as ILC or CLIC. To achieve that, precise controls of aberrations such as dispersion and coupling are necessary. Initially, coupling correction upstream of the final focus line of the ATF2 will be performed with only two skew quadrupoles (SQ) in the extraction line (EXT). We thus first examine the feasability of coupling correction in the EXT with those two SQ, considering several possible coupling error sources. The correction is first based on an algorithm of minimisation of vertical emittance with successive skew scans, implemented in the Flight Simulator code*. We will then investigate new methods to measure and extract the first order four coupling parameters of the beam matrix in order to perform a more direct and accurate coupling correction.

*G. White et al., "A flight simulator for ATF2…", TUPP016 EPAC08

• C.M. Gulliford, I.V. Bazarov, M.J. Forster, A.K. Kim
  CLASSE, Ithaca, New York

Commissioning of a new high brightness electron source for the Energy Recovery Linac at Cornell University is currently underway. Despite the fact that the beam dynamics in this portion of the accelerator is space-charge dominated, a fundamental understanding of the machine linear optics is crucial in that it determines the effectiveness of space-charge emittance compensation methods, as well as provides the means to achieving various beam parameters such as beam length and energy spread. Here we introduce a new numerical tool being used in the commissioning of the injector that provides linear optics matrix calculation using field maps for various optical elements.

• O.A. Anderson
  LBNL, Berkeley, California
• L.L. LoDestro
  LLNL, Livermore, California

Funding: Supported in part by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

In 1958, Courant and Snyder analyzed the problem of alternating-gradient beam transport and treated a model without focusing gaps or space charge.* We extend their work to include the effect of gaps (still neglecting space charge) and obtain exact solutions for the matched envelopes.** We assume a periodic lattice of quadrupole doublets. The focus sections have piecewise-constant field strength and equal lengths, but the zero-field drift sections have arbitrary length ratio. We obtain and show the exact envelope results as functions of z for various field strengths, occupancies (eta), and gap-length ratios. We show the peak envelope excursion as a function of field strength or phase advance (σ) for various cases. There is a broad σ range over which the minimum peak varies less than ± 1%. For eta = 1, this range is 64 to 98 degrees; for eta = 0.5, it is 62 to 96 degrees. In the lowest stable band, the optimum field strength rises by 37.6% when eta is reduced from 1.0 to 0.5 and rises by 76.0% if also one gap has zero length. In the second stable band, the higher field strength accentuates the remarkable compression effect predicted for the FD (gapless) model.**

*E.D. Courant and H.S. Snyder, Ann. Phys. 3, 1 (1958).
**The present work extends a recent envelope analysis carried out without gaps (O.A. Anderson and L.L. LoDestro, submitted to Phys. Rev. ST-AB).

• W. Wan, A. Zholents
  LBNL, Berkeley, California

Analytical formula of the 6X6 transfer matrix of a magnetic solenoid is derived. As an example, analytical and numerical study of a bunch compressor consists of such solenoids is presented.

• J.S. Kolski, R.J. Macek, R.C. McCrady
  LANL, Los Alamos, New Mexico
• J.S. Kolski
  IUCF, Bloomington, Indiana

Funding: US DOE #DE-AC52-06NA25396

Orbit response matrix techniques have been used in numerous electron storage rings to elucidate various optical properties of the machines. Such measurements in a long-pulse accumulator ring have unique complications. We present here the techniques and results of such a measurement at the Los Alamos Proton Storage Ring*. We also show the deficiencies in previous models of the ring and a comparison of the beta-functions as fit by the orbit response method to direct measurements by quadrupole magnet variations.

*LA-UR- 08-07694

• A.I. Papash
  MPI-K, Heidelberg
• C.P. Welsch
  Cockcroft Institute, Warrington, Cheshire

Funding: Work supported by the Helmholtz Association of National Research Centers (HGF) under contract number VH-NG-328 and GSI Helmholtzzentrum für Schwerionenforschung GmbH

In the future Facility for Low-energy Antiproton and Ion Research (FLAIR) at GSI, the Ultra-low energy electrostatic Storage Ring (USR) will provide cooled beams of antiprotons and possibly also highly charged ions down to energies of 20 keV/q. A large variety of the envisaged experiments demands a very flexible ring lattice to provide a beam with variable cross section, shape and time structure, ranging from ultra-short pulses to coasting beams. The preliminary design of the USR worked out in 2005 was not optimized in this respect and had to be reconsidered. In this contribution we present the final layout of the USR with a focus on its “split-achromat” geometry, the combined fast/slow extraction, and show the different modes of operation required for electron cooling, internal experiments, or beam extraction. We finally give a summary of the machine parameters and the layout of the optical elements.

• Y.K. Batygin
  NSCL, East Lansing, Michigan
• M. Woodley
  SLAC, Menlo Park, California

Determination of exact values of beam emittance is important for future linear collider. Beam emittance measurements technique is based on measurement of beam sizes at several beam profile stations in a quadrupole channel shifted between each other by a specific value of phase advance of betatron oscillations. Four-dimensional beam emittance measuremenst requires determination of ten values of the beam σ-matrix, while two-dimensional beam emittance measurements scheme requires determination of six values of σ-matrix. Measurement procedure is sensitive to variation of beam sizes at the beam profile stations, which might result in unstable determination of beam emittance. Paper discusses errors of beam emittance measurements as a function of errors in beam size measurement. Regions of stable and unstable beam emittance measurements are determined.

• M. Portillo, G. Bollen, S. Chouhan, O.K. Kester, G. Machicoane, J. Ottarson, S. Schwarz, A. Zeller
  NSCL, East Lansing, Michigan

Funding: This work was supported by Michigan State University and the National Science Foundation under grant PHY-0110253.

The NSCL at Michigan State University (MSU) is implementing a system called the ReA3 to reaccelerate rare isotope beams from projectile fragmentation to energies of about 3 MeV/u. The re-acceleration system uses an Electron Beam Ion Trap (EBIT) to provide a compact and cost efficient system. We discuss the design parameters for a m/q separator that is to be used to separate highly charged ions from an EBIT type charge breeder. The separator is designed to accept ions at 12 keV/u with mass to charge ratios in the range of m/q = 2.5 to 5 amu. The goal is to separate selected rare isotope species from any residual ions before injecting them into the ReA3 linear accelerator system. Using ray tracing simulations with SIMION*, as well as higher order map calculations with COSY INFINITY**, the performance of the separator has been evaluated in terms of the expected mass resolution and overall acceptance. The separator consists of a magnetic sector and a series of electrostatic devices to obtain a first order achromatic tune. For comparison, similar performance values will be derived as those for a similar separator constructed at REX-ISOLDE***.

*D.A. Dahl, Int. J. Mass Spectrom. Ion Processes 200, 3 (2000) .
**K. Makino and M. Berz, Nucl. Instr. and Meth. A 558, 346 (2005)
***R. Rao et. al., EPAC-98, Stockholm, Sweden, 2132-2134 (1998).

• M. Chung
  Fermilab, Batavia
• M. Chung, R.C. Davidson, P. Efthimion, E.P. Gilson, R. M. Majeski
  PPPL, Princeton, New Jersey

Funding: Research supported by the U.S. Department of Energy.

Understanding the effects of random errors in machine components such as quadrupole magnets and RF cavities is essential for the optimum design and stable operation of high-intensity accelerators. The effects of random errors have been studied theoretically, but systematic experimental studies have been somewhat limited due to the lack of dedicated experimental facilities. In this paper, based on the compelling physics analogy between intense beam propagation through a periodic focusing quadrupole magnet system and pure ion plasma confined in a linear Paul trap, experimental studies of random error effects have been performed using the Paul Trap Simulator Experiment (PTSX). It is shown that random errors in the quadrupole focusing strength continuously produce a non-thermal tail of trapped ions, and increases the rms radius and the transverse emittance almost linearly with the amplitude and duration of the noise. This result is consistent with 2D WARP PIC simulations. In particular, it is observed that random error effect can be further enhanced in the presence of beam mismatch.

• H. Qin, R.C. Davidson
  PPPL, Princeton, New Jersey

Funding: Supported by the U.S. Department of Energy.

For applications of high-intensity beams in heavy ion inertial confinement fusion and high energy density physics, solenoidal focusing lattice and transverse wobblers can be used to achieve uniform illumination of the target and for suppressing deleterious instabilities. A generalized self-consistent Kapchinskij-Vladimirskij solution of the nonlinear Vlasov-Maxwell equations is derived for high-intensity beams in a solenoidal focusing lattice with transverse wobblers. The cross-section of the beam is an ellipse with dynamical centroid, titling angle, and transverse dimensions that are determined from 5 envelope-like equations.

• T.W. Koeth
  Rutgers University, The State University of New Jersey, Piscataway, New Jersey
• H.T. Edwards, A.S. Johnson, A.H. Lumpkin, J. Ruan, Y.-E. Sun, R. Thurman-Keup
  Fermilab, Batavia
• R.P. Fliller
  BNL, Upton, Long Island, New York

A transverse to longitudinal emittance exchange experiment is installed at the Fermilab A0 Photoinjector. We report on the completed measurement of emittance exchange transport matrix as well as the ongoing program to directly measure the emittance exchange. Both the transverse and longitudinal input beam parameters are being explored in order to achieve direct emittance exchange with minimal dilution effects

• L.G. Liu
  SSRF, Shanghai

Funding: SSRF

The ssrf is a 3rd generation light source under commissioning. The commissioning of the storage ring has progressed very well so far. The periodicity and symmetry of the linear optics in a real storage ring is important, however maybe be broken by various errors, such as field errors, manufactured errors. A distorted linear optics can excite stronger nonlinear resonances, which will reduce the storage ring dynamic aperture and make the storage ring suffer from low injection efficiency and short beam lifetime. Therefore, it is necessary to restore the designed periodicity or symmetry of the linear optics based on measured closed orbit distortion. The calibration procedure can be done by using LOCO (the Linear Optics from Closed Orbit). After fitting the measured response matrix by the model one, the linear optics of the storage ring is calibrated. And different operation modes have been also measured and calibrated.

• C. Kwankasem, S. Chunjarean
  SLRI, Nakhon Ratchasima

For the SIAM Photon Source, we propose to establish a storage ring model based on quadrupole fitting of the measured betatron functions. By fitting of quadrupole field strength parameters to measured values of the betatron function, a series of problems at the SIAM Photon Source could be determined. For example, the problem of turn-to turn electrical coil shorts was detected and solved by replacing the new quadrupole coils. Subsequently, we could identify a quadrupole calibration error due to conflicting information on the number of turns per coil. Other causes regarding the beam dynamics model such as high field saturation effects, power supply calibration error, and proximity to nearby magnets have been taken into account to establish accurate quadrupole calibration factors. The establishment of an accurate model is essential for beam dynamics predictions, closed orbit correction, response matrix determination for LOCO, low emittance operation, and optics correction for high filed insertion devices.

• K.G. Panagiotidis
  The University of Liverpool, Liverpool
• K.G. Panagiotidis, A. Wolski
  Cockcroft Institute, Warrington, Cheshire

The specified vertical emittance for the ILC damping rings is 2 pm. A major objective for the Accelerator Test Facility (ATF) at KEK is to demonstrate reliable operation in this low emittance regime. LOCO is a tool for identifying optics errors in storage rings, based on fitting a lattice model to the measured closed orbit response matrix. This technique can be used to determine corrections to minimise vertical dispersion and betatron coupling, and hence reduce the vertical emittance. So far, efforts to apply LOCO to the ATF to achieve 2 pm vertical emittance have met with limited success. This paper presents the results of simulations aiming to identify possible limitations in the technique. We consider the effects of varying parameters controlling the fit of the lattice model to the measured data, and investigate possible degeneracies (e.g. between skew quadrupole strengths and tilts of the corrector magnets) that may limit the quality of the correction achievable using this technique.

• G. Feng, W. Li, L. Liu, L. Wang, C.-F. Wu, H. Xu, S.C. Zhang
  USTC/NSRL, Hefei, Anhui

In order to meet the increasing requirements of synchrotron radiation users, a new plan of VUV and soft X-ray light source, named Hefei Advanced Light Source (HALS), is brought forward by National Synchrotron Radiation Laboratory (NSRL). This 1.5GeV storage ring with ultra low emittance 0.2nmrad consists of 18 combined FBA cells and the circumference is 388m. Strong enough quadrupoles and sextupoles must be needed for getting such low emittance lattice, which will lead beam close orbit distortions’ (COD) sensitivity to the field and alignment errors in magnets. Estimation of the COD from various error sources is investigated. Using orbit response matrix and singular value decomposition method, the distribution of beam position monitors and the location of correctors are reported in the paper. Simulation proves that COD can be corrected down to 60 microns level. In the same time the corrector strengths are weaker enough in the correction scheme.

• J.Z. Zhou, C. Chen, K.R. Samokhvalova
  MIT/PSFC, Cambridge, Massachusetts

Funding: This work was supported by the Department of Energy, Grant No. DE-FG02-95ER40919 and the Air Force Office of Scientific Research, Grant No. FA9550-06-1-0269.

An adiabatic warm-fluid equilibrium theory for a thermal charged-particle beam in an alternating gradient (AG) focusing field is presented. Warm-fluid equilibrium equations are solved in the paraxial approximation and the rms beam envelope equations and the self-consistent Poisson equation, governing the beam density and potential distributions, are derived. The theory predicts that the 4D rms thermal emittance of the beam is conserved, but the 2D rms thermal emittances are not constant. Although the presented rms beam envelope equations have the same form as the previously known rms beam envelope equations, the evolution of the rms emittances in the present theory is given by analytical expressions. The beam density is calculated numerically, and it does not have the simplest elliptical symmetry, but the constant density contours are ellipses whose aspect ratio decreases as the density decreases along the transverse displacement from the beam axis. For high-intensity beams, the beam density profile is flat in the center of the beam and falls off rapidly within a few Debye lengths, and the rate at which the density falls is approximately isotropic in the transverse directions.

• E. Startsev, R.C. Davidson, M. Dorf
  PPPL, Princeton, New Jersey

Funding: Research supported by the U. S. Department of Energy.

The transverse dynamics of an intense charged particle beam propagating through a periodic quadrupole focusing lattice is described by the nonlinear Vlasov-Maxwell system of equations where the propagating distance plays the role of time. To find matched-beam quasi-equilibrium distribution functions one need to determine a dynamical invariant for the beam particle moving in the combined external and self-fields. The standard approach for sufficiently small phase advance is to use the smooth focusing approximation, where particle dynamics is determined iteratively using the small parameter (vacuum phase advance)/(360 degrees) < 1 accurate to cubic order. In this paper, we present a perturbative Hamiltonian transformation method which is used to transform away the fast particle oscillations and obtain the average Hamiltonian accurate to 5th order in the expansion parameter. This average Hamiltonian, expressed in the original phase-space variables, is an approximate invariant of the original system, and can be used to determine self-consistent beam equilibria that are matched to the focusing channel.

• S.B. van der Geer
  Pulsar Physics, Eindhoven
• B.D. Muratori
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• M.J. de Loos, S.B. van der Geer
  TUE, Eindhoven

The required strengths of quadrupoles in a phase-space tomography section are significantly affected by the total charge per bunch. Finding settings at a high charge is challenging because of the non-linear nature of Coulomb interactions. This is further hindered by the inability to use thin-lens approximations and dependence on numerical simulations. Finally, one faces the problem that at some charge there simply is no solution at all. In this contribution we describe a simple procedure, implemented in the General Particle Tracer (GPT) code, which can be used to find optimal beamline settings in the presence of space-charge forces. The recipe 'transports' the settings for a zero-charge solution to those of the desired charge and it gives an indication what the maximum tolerable charge is.

• A. Fukasawa, H. Badakov, B.D. O'Shea, J.B. Rosenzweig
  UCLA, Los Angeles, California
• D. Alesini, L. Ficcadenti, B. Spataro
  INFN/LNF, Frascati (Roma)
• L. Palumbo
  Rome University La Sapienza, Roma

A hybrid photoinjector, which we present here, consists of a 6-cell traveling wave structure with a standard 1.6-cell RF gun attached to the one end and a 3-m long linac following for further acceleration. With this structure, no reflection observed at the input port. This enables to build the accelerator without a circulator which limits the power and the frequency of RF. From the beam dynamics point of view, the beam is produced as the normal RF guns and gets short by velocity bunching in the traveling wave section right after the gun. The peak current can reach more than 1 kA, with about 2 mm.mrad of the emittance at 20 MeV. We discuss more details about the beam dynamics as well as the RF structure.

• S. Bernal, B.L. Beaudoin, M. Cornacchia, K. Fiuza, I. Haber, R.A. Kishek, T.W. Koeth, P.G. O'Shea, C. F. Papadopoulos, M. Reiser, D.F. Sutter, C. Wu
  UMD, College Park, Maryland

Funding: This work is funded by the US Dept. of Energy Offices of High Energy Physics and High Energy Density Physics, and by the US Dept. of Defense Office of Naval Research and Joint Technology Office

The University of Maryland Electron Ring (UMER) can operate over a broader range of beam intensities than other circular machines. Naturally, transverse and longitudinal space charge effects limit the ability to store beams. In UMER, the resonance properties of the machine in the two regimes of operation, emittance- and space charge-dominated transport, differ significantly. We report on studies of linear betatron resonances in UMER from 0.6 mA to 80 mA beam current, corresponding to theoretical space charge incoherent tune shifts well over the Lasslet limit. The observations are related to existing theories as well as to computer simulations. We also describe the instrumentation and techniques used for tune measurements.

• R.A. Kishek, B.L. Beaudoin, S. Bernal, M. Cornacchia, I. Haber, P.G. O'Shea, M. Reiser, D.F. Sutter, J.C.T. Thangaraj, C. Wu
  UMD, College Park, Maryland
• D. Stratakis
  BNL, Upton, Long Island, New York

Funding: This work is funded by the US Dept. of Energy Offices of High Energy Physics and High Energy Density Physics, and by the US Dept. of Defense Office of Naval Research and Joint Technology Office

Beam matching is critical for avoiding envelope mismatch oscillations that can lead to emittance growth and halo formation, especially if the beam has significant space charge. The University of Maryland Electron Ring (UMER) is a research storage ring that is designed for scaled studies that are applicable to many larger machines. Using 10 keV electron beams at relatively high current (0.6 – 100 mA), space charge forces are relatively strong. Matching of the UMER beam is rendered difficult by the space charge, the crowdedness of the lattice, and especially the unique injection scheme where an offset oversized quadrupole is shared between the ring and the injector. In this paper we discuss several schemes for optimizing the matching at injection, both analytical and beam-based, which we test using particle-in-cell simulations with the code, WARP. Comparison to UMER experimental data is provided where available.

• S. Franke, W. Ackermann, T. Weiland
  TEMF, TU Darmstadt, Darmstadt
• J. Enders, C. Heßler, Y. Poltoratska
  TU Darmstadt, Darmstadt

Funding: This work was supported by DFG through SFB 634.

Based on the moment approach a fast tracking code named V-Code has been implemented at TEMF. Instead of using the particle distribution itself this method applies a discrete set of moments of the particle distribution. The time evolution of each moment can be deduced from the Vlasov equation when all essential external forces are known. These forces are given by the Lorentz equation in combination with the distribution of electric and magnetic fields. For efficiency reasons the 3D fields in the vicinity of the bunch trajectory are reconstructed in V-Code from one-dimensional field components by means of proper multipole expansions for the individual beam line elements. The entire beam line is represented in the code as a successive alignment of separate independent beam line elements. The proximity of some beam forming elements may lead to overlapping fringe fields between consecutive elements. In order to simulate even such beam lines with the V-Code, its database of disjunctive beam line elements has to be enhanced to deal also with superposed fields. In this paper a summary of issues regarding the implementation complemented with simulation results will be provided.

• D. Schiller
  UCLA, Los Angeles, California
• S. Reiche
  PSI, Villigen

QUINDI has been developed to address the numerical challenge of calculating the radiation spectra from electron bunches in bending magnet systems. Since the introduction of QUINDI, many improvements and features have been added. QUINDI now supports a 3D model for bending magnets which includes fringing fields. A more modular approach has been achieved which allows better interoperability with other tracking and radiation codes. There have been many updates to the electric field calculation and spectrum processing, as well as to the post-processor, SpecGUI.

• R. Calaga
  BNL, Upton, Long Island, New York
• G. Arduini, E. Métral, G. Papotti, D. Quatraro, G. Rumolo, B. Salvant, R. Tomás
  CERN, Geneva

Funding: This work has been partially performed under the auspices of US department of energy

Measurements of transverse impedance in the SPS to track the evolution over the last few years show discrepancies compared to the analytical estimates of the major contributors. Recent measurements to localize the major sources of the transverse impedance using intensity dependent optics are presented. Some simulations using HEADTAIL to understand the limitations of the reconstruction and related numerical aspects are also discussed.

• E.N. Shaposhnikova, T. Bohl, H. Damerau, K. Hanke, T.P.R. Linnecar, B. Mikulec, J. Tan, J. Tuckmantel
  CERN, Geneva

First reference measurements of the longitudinal impedance were made with beam in the SPS machine in 1999 to quantify the results of the impedance reduction programme, completed in 2001. The 2001 data showed that the low-frequency inductive impedance had been reduced by a factor 2.5 and that bunch lengthening due to the microwave instability was absent up to the ultimate LHC bunch intensity. Measurements of the quadrupole frequency shift with intensity in the following years suggest a significant increase in impedance (which nevertheless remains below the 1999 level) due to the installation of eight extraction kickers for beam transfer to the LHC. Microwave instability is still not observed up to the maximum bunch intensities available from injector. The experimental results are compared with expectations based on the known longitudinal impedance of the different machine elements in the SPS.

• L.K. Spentzouris
  Illinois Institute of Technology, Chicago, Illinois
• D.O. McCarron
  IIT, Chicago, Illinois
• W. Pellico, P. Spentzouris, E.G. Stern, R.E. Tomlin
  Fermilab, Batavia

Funding: This work supported by NSF grant No. 0237162, and DOE SCIentific Discovery through Advanced Computing: Accelerator science and simulation DE-PS02-07ER07-09

The FNAL Booster is a combined-function proton synchrotron with a bunch intensity of ~6·10¹⁰ protons; significantly greater than expected in the original design. The injection energy is 400 MeV (gamma factor 1.4), low enough for space charge forces to play a role in beam dynamics. The magnets are used directly as vacuum tanks, so the laminated pole surfaces contribute significantly to impedance. A study of the transverse coupling dependence on beam intensity is presented here. Experimental results are being analyzed using Synergia, a high-fidelity, parallel, fully 3D modeling code that includes both space charge and impedance dynamics. Previously, Synergia has always shown good agreement with experimental data. Our initial studies show that the direct space charge contribution to beam dynamics is too small to account for the increase in the coupling seen experimentally, corroborating analytic results. Parametric studies of the impedance needed to match the measured coupling are being done. Agreement between simulation and experiment should provide an independent measure of the Booster impedance, which has been analytically modeled and calculated elsewhere.

• R.J. Macek, R.C. McCrady, L. Rybarcyk, T. Zaugg
  LANL, Los Alamos, New Mexico
• A. A. Browman
  TechSource, Santa Fe, New Mexico

Funding: Work supported, in part, by DOE SBIR Grant No. DE-FG02-04ER84105 and CRADA No. LA05C10535 between TechSource, Inc. and the Los Alamos National Laboratory.

Recent beam studies have focused on understanding the main sources and locations of electron clouds (EC) which drive the observed e-p instability at the Los Alamos Proton Storage Ring (PSR). Strong EC signals are observed in drift spaces and quadrupole magnets at PSR which together cover ~65% of the ring circumference. New results making use of two longitudinal barriers to isolate the drift space electron diagnostic provide definitive evidence that most of the drift space EC signal is “seeded” by electrons ejected longitudinally by ExB drifts from adjacent quadrupole magnets. This result can explain why weak solenoids and TiN coatings in several drifts spaces had no effect on the e-p instability threshold. Modeling of EC generation in 3D quadrupoles using a modified version of the POSINST code shows that a sizeable fraction of the electrons generated in the quadrupoles are ejected longitudinally into the adjacent drifts. The experimental findings and simulation results will be presented.

• E.P. Gilson, R.C. Davidson, M. Dorf, P. Efthimion, R. M. Majeski, E. Startsev
  PPPL, Princeton, New Jersey

Funding: Research supported by the U.S. Department of Energy.

The Paul Trap Simulator Experiment (PTSX) is a compact laboratory Paul trap that simulates a long, thin charged-particle bunch coasting through a kilometers-long magnetic alternating-gradient (AG) transport system by putting the physicist in the frame-of-reference of the beam. Results are presented from experiments in which the axial distribution function is modified by lowering the axial confinement barrier to allow particles in the tail of the axial distribution function to escape. Measurements of the axial energy distribution and the transverse density profile are taken to determine the effects of the modified distribution function on the charge bunch. It is observed that the reduced axial-trapping potential leads to an increase of the transverse effective temperature.

• S. Molloy, G.R. White, M. Woodley
  SLAC, Menlo Park, California

The Flight Simulator is a Matlab middleware layer which uses the Lucretia beam tracking engine and a lower level EPICS control system to allow the development of beam control and monitoring algorithms in a simulation environment that appears identical to the that of the control room. The goal of ATF2 is to test a novel compact final final focus optics design intended for use in future linear colliders. The newly designed extraction line and final focus system will be used to produce a 37nm vertical waist from the extracted beam. Alignment of the magnetic elements is of vital importance for this goal and it is expected that beam-based alignment (BBA) techniques will be necessary to achieve the necessary tolerances. This paper describes a package for the beam-based alignment of quadrupole and sextupole magnets in the ATF2 damping ring, extraction line, and final focus system. It brings together several common techniques for the alignment of magnetic elements, and has been implemented as a GUI-based tool that may be used on its own, or integrated with other routines. The design of this package is described, and simulation and beam results are shown.

• B.J.A. Shepherd, J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

The ALICE accelerator is a 35MeV energy recovery linac prototype at Daresbury in the U.K. Due to the highly experimental nature of the accelerator, there has been a strong influence of accelerator physicists in the high-level control software for the machine. Starting from the underlying EPICS-based control system, a suite of interactive commissioning software has been built using traditional software approaches, such as LabVIEW, as well as experimenting with interactive, rapid prototyping programming languages, such as Mathematica. Using the EPICS Channel Access protocols, the control system is flexible and extensible. A wide range of tools can be used to develop and debug high-level software, allowing machine physicists to use the most appropriate and familiar tools for software development.

• M.O.A. El Ghazaly
  KUK, Abha
• M.H. Al-Malki, M.O.A. El Ghazaly
  KACST, Riyadh
• A.I. Papash
  MPI-K, Heidelberg
• C.P. Welsch
  Cockcroft Institute, Warrington, Cheshire

A state-of-the-art fixed energy electrostatic storage ring that will allow for precision experiments with most different kinds of ions in the energy range of up to 30 keV will be constructed and operated at the National Center for Mathematic and Physics (NCMP) at the King Abdulaziz City for Science and Technology (KACST). The ring is planed to be the central machine of a unique and highly flexible experimental platform. The lattice design therefore has to cover the different experimental techniques that the ring will be equipped with, such as e.g. electron-ion crossed-beams and ion-laser/ion-ion/ion-neutral merged-beams techniques. This paper presents the technical and particle optical design of this novel machine, explains the particular challenges in its layout, and reports on the general project status.

• J.-P. Carneiro, I.G. Gonin, N. Solyak, V.P. Yakovlev
  Fermilab, Batavia
• W. Hartung
  NSCL, East Lansing, Michigan
• B. Mustapha, P.N. Ostroumov
  ANL, Argonne

A superconducting cavity has been designed for acceleration of particles traveling at 81% the speed of light (beta = 0.81). The application of interest is an 8 GeV proton linac proposed for a Fermilab upgrade; at present, the cavity is to be used from 420 MeV to 1.3 GeV. The cavity is similar to the 805 MHz high-beta cavity developed for the SNS Linac, but the resonant frequency (1.3 GHz) and beam tube diameter (78 mm) are the same as for the beta = 1 cavities developed for the TESLA Test Facility. Four single-cell prototype cavities have been fabricated and tested. Two multi-cell prototypes have also been fabricated, but they have not yet been tested. The original concept was for an 8-cell cavity, but the final design and prototyping was done for 7 cells. An 11-cell cavity was proposed recently to allow the cryomodules for the beta = 0.81 cavity and downstream 9-cell beta = 1 cavities to be identical. The choice of number of cells per cavity affects the linac design in several ways. The impact of the number of cells in the 8 GeV linac design will be explored in this paper. Beam dynamics simulations from the ANL code TRACK will be presented.

• S.S. Kurennoy, J.F. O'Hara, E.R. Olivas, L. Rybarcyk
  LANL, Los Alamos, New Mexico

We are developing high-efficiency room-temperature RF accelerating structures based on inter-digital H-mode (IH) cavities and the transverse beam focusing with permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. Such IH-PMQ accelerating structures following a short RFQ can be used in the front end of ion linacs or in stand-alone applications such as a compact deuteron-beam accelerator up to the energy of several MeV. New results from our detailed electromagnetic 3-D modeling combined with beam dynamics simulations and thermal-stress analysis for a complete IH-PMQ accelerator tank, including the end-cell design, will be presented.

• D.C. Plostinar
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

Future projects like a neutrino factory or an advanced spallation neutron source require high power proton accelerators capable of producing beams in the multi-MW range. The quality of the beam delivered to the target is very much dictated by the accelerator front end and by the lower energy linac. Prompted by the Front End Test Stand (FETS) under construction at Rutherford Appleton Laboratory (RAL), a new 800 MeV H^- linac is being considered as part of a possible MW upgrade for ISIS. Preliminary simulations of high intensity beam dynamics and beam transport in the new linac suggest that a re-evaluation of the front end Medium Energy Beam Transport (MEBT) line is necessary. In this paper different optical designs for the 3 MeV MEBT line are presented and their impact on the subsequent Drift Tube Linac (DTL) section is being analysed.

• G.H. Rees
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

Features of a linac and ring for potential ISIS upgrades are outlined. Maximum parameters are 0.8 GeV, 0.5 MW for the H(-)linac and 3.2 GeV, 2 MW for the ring, both at 30 or 50 Hz. The linac is based on a 324 MHz frequency at low energies, having an ion source, LEBT, 3 MeV RFQ and MEBT, with A 74.8 MeV drift tube linac (DTL) and intermediate energy beam transport (IEBT). The MEBT chopper stage uses solenoid and triplet focusing, and both MEBT and IEBT have long sections for beam collimation. There are three options for the higher energies, a 648 MHz superconducting linac(ScL1, ScL2 and ScL3), a 648 MHz (CCL, ScL2 and ScL3), and a 324 MHz (ScLa) with a two-stage 972 MHz (ScLb and ScLc). The ScL1, CCL and ScLa are designed to accelerate the H(-) beam from 74.8 to ~200 MeV. The proton synchrotron design is based on a five superperiod lattice of doublet and triplet cells, and has a circumference of ~ 370 m.

• S. An, S.M. Wei, T.J. Zhang
  CIAE, Beijing
• K. Bongardt
  FZJ, Jülich

The 10 mA, 40keV H^- pulsed injection line for the CIAE 10 MeV CRM cyclotron has two main operation modes for bunched beams: delivering 5 mA CW beam or chopped pulse with more than 100uA. Chopped pulse is achieved by placing behind the 70.5 MHz bunching cavity a sinusoidal transverse deflecting cavity with frequency of 2.2 MHz, 1/32 of the bunching frequency. Particles outside the wanted ±3° phase width @ 2.2 MHz, corresponding to ±90° @ 70.5 MHz, are either absorbed in a 50cm drift after chopper or at round slit1, 1cm aperture. Time dependence of sinusoidal chopping field causes RMS emittance increase by a factor 3 and changes twiss parameter alpha by a factor 2 before the round slit1. Solenoid couples motion in transversal planes, but equalizes both RMS emittances. Particle tracking results are presented for the chopped pulse, showing longitudinal-transverse coupling in the deflector and equalization of RMS emittances in the solenoid. Optimised focusing strength leads to about 1 % transmission efficiency for the chopped pulse. The CRM inflector receives 2.4 ns long pulse at about 4.4 MHz repetition rate, 1/16 of the RF frequency.

• L. Picardi, C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)
• P. Panichelli, G. Prete, F.P. Romano, G. Valentini
  SPARKLE S.r.l., Casarano (Lecce)

SPARKLE company is setting up in the south of Italy (Casarano) a new cyclotron facility based on a 18 MeV, 150 uA IBA Cyclone 18/9. The aim is to create a multidisciplinary research site for the medical applications of accelerators. The main activity will be the production of standard and new radionuclides, by internal targets and one external beam line. Another opposite beam line has been reserved for low current proton irradiations for radiotherapy studies, and a linac booster between 18 and 24 MeV was designed and built to this end. The beam line, which focuses and matches the beam to the linac, includes a chopping system to synchronize the beam to the pulsed linac and to collect 99% of the beam not synchronous to the linac. The linac uses a 3 GHz SCDTL structure powered by a magnetron modulator system. In the paper we report an overview of the beam line, component design, and tests.

• D.J. Holder
  Cockcroft Institute, Warrington, Cheshire
• B.D. Muratori
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG currently under construction at Daresbury Laboratory. The energy recovery linac prototype ALICE will operate as its injector, at a reduced the energy of 10 to 20 MeV, compared to its nominal energy of 35 MeV. An injection line has been designed which consists of a dogleg to extract the beam from ALICE, a matching section, a tomography section and some additional dipoles and quadrupoles to transport and match the beam to the entrance of EMMA. This injection line serves both as a diagnostic to measure the properties of the beam being injected into EMMA and also a useful diagnostic tool for ALICE operation. This paper details the simulations undertaken of the electron beam passing through the matching and tomography sections of the EMMA injection line, including the effect of space charge. This will be an issue in the energy range at which this diagnostic is being operated when combined with high bunch charge. A number of different scenarios have been modelled and an attempt made to compensate for the effects of space charge in the matching and tomography sections.

• C.N. Davids, D. Peterson
  ANL, Argonne

Funding: This work was supported between the UChicago, Argonne, LLC and the Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

We have designed a compact high-resolution isobar separator for CARIBU* at the ATLAS accelerator facility at Argonne National Laboratory. Fission fragments from a 252Cf source are thermalized, cooled, and accelerated to 50 keV. The small longitudinal emittance of this cooled beam allows the use of pure magnetic dispersion for mass analysis. Using two 60° bending magnets, two electrostatic quadrupole doublets, and two electrostatic quadrupole singlets in a symmetric combination, a first-order mass resolution of 22,400 is calculated. Aberration correction up to 5th order is accomplished by means of two electrostatic hexapole singlets and a 48-rod electrostatic multipole lens with hexapole, octupole, decapole, and dodecapole components. The fields with critical tolerances are the quadrupole singlets (±1x10-3) and the hexapole component of the multipole (±2x10-3). Ion-optics calculations were performed using the program COSY INFINITY**. The resulting ion trajectories and mass spectra will be presented. All electrostatic elements have been constructed, and delivery of the magnets is expected in early 2009. A progress report on installation and commissioning will be presented.

*See invited talk by R. Pardo at this conference.
**Version 8.1, M. Berz et al., (2002).

• S.A. Litvinov, A. Dolinskyy, O.E. Gorda, F. Nolden, M. Steck
  GSI, Darmstadt

The main purpose of the Recuperated Experimental Storage Ring (RESR) in the FAIR project is the accumulation of antiprotons coming from the Collector Ring (CR), where they are stochastically pre-cooled. The accumulation scheme in the RESR foresees longitudinal stacking in combination with stochastic cooling. The stochastic cooling process strongly depends on the slip factor η of the ring. Presently, the RESR is designed to operate with small slip factor of 0.03. In order to increase the flexibility for optimized stochastic cooling a new alternative ion-optical mode with higher slip factor of 0.11 has been calculated in such a way, that the RESR can be operated with a fixed magnetic structure in both modes. The influence of the high-order chromaticity on the particle motion has been investigated and a chromaticity correction scheme is applied. The variation of the transition energy over the momentum acceptance was examined and the possibility of its correction is described.