• L. R. Evans
  

• M. Eriksson
  
• M. Berglund, M. Brandin, D. Kumbaro, P. Lilja, L.-J. Lindgren, L. Malmgren, M. Sjostrom, S. Thorin, E. J. Wallen, S. Werin
  MAX-lab, Lund
• H. Tarawneh
  SESAME, Amman

• S. Ozaki
  
• J. Bengtsson, S. L. Kramer, S. Krinsky, V. Litvinenko
  BNL, Upton, Long Island, New York

• M.-H. Wang
  
• H.-P. Chang, H. C. Chao, P. J. Chou, C.-C. Kuo
  NSRRC, Hsinchu
• S.-Y. Lee, F. Wang
  IUCF, Bloomington, Indiana

• R. Kersevan
  
• L. Goirand
  ESRF, Grenoble

• H. Soltner
  
• M. Pabst, R. Tolle
  FZJ, Julich

• D. Zangrando
  
• D. Castronovo, M. Svandrlik, R. Visintini
  ELETTRA, Basovizza, Trieste

• C. K. Allen
  
• H. Ikeda
  Visual Information Center, Inc., Ibaraki-ken
• M. Ikegami
  KEK, Ibaraki
• T. Ohkawa
  JAEA, Ibaraki-ken
• H. Sako, G. B. Shen
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• A. Ueno
  JAEA/LINAC, Ibaraki-ken

The XAL application development environment has been installed as a part of the control system for the Japan Proton Accelerator Research Center (J-PARC). XAL was initially developed at SNS and has been described at length in previous conference proceedings (e.g., Chu et. al. APAC07, Galambos et. al. PAC05, etc.). The fundamental tenet of XAL is to provide a consistent, high-level programming interface, along with a set of high-level application tools, all of which are independent of the underlying machine hardware. Control applications can be built that run at any accelerator site where XAL is installed. Of course each site typically has specific needs not supported by XAL and the framework was designed with this in mind: each institution can upgrade XAL which then is accessible to all users. We outline the upgrades and enhancements to the XAL online model necessary for accurate simulation of the J-PARC linac. For example, we have added permanent magnet quadrupoles and additional space charge capabilities such as off-centered and rotated beams and bending magnets with space charge. We present the physics models for the upgrades as well as the software architecture supporting them.

• M. M. Shehab
  
• G. Vignola
  SESAME, Amman

• E. Al-Dmour
  
• D. Einfeld, M. Q. Quispe
  ALBA, Bellaterra (Cerdanyola del Valles)

• K. Artoos
  
• S. Bartolome-Jimenez, O. Capatina, J. M. Chevalley, K. Foraz, M. Guinchard, C. Hauviller, K. Kershaw, S. Prodon, I. Ruehl, G. Trinquart, S. Weisz
  CERN, Geneva
• P. Ponsot
  DBS, Saint Genis-Pouilly

• A. Poncet
  
• P. Cruikshank, V. Parma, P. M. Strubin, J.-P. G. Tock, D. Tommasini
  CERN, Geneva

• E. Todesco
  
• F. Borgnolutti
  CERN, Geneva
• A. Mailfert
  ENSEM, Vandoeuvre les Nancy

Studies for the LHC luminosity upgrade showed the need for quadrupoles with apertures much larger than the present baseline (70 mm). In this paper we focus on the design issues of a 130 mm aperture quadrupole. We first consider the Nb-Ti option, presenting the magnetic design with the LHC dipole cable. We study the Lorentz forces and we discuss the field quality constraints. For the Nb3Sn option we sketch two designs, the first based on the LARP 10 mm cable, and the second one on a 15 mm cable. The issue of the stress induced by the Lorentz forces, which is critical for the Nb3Sn, is discussed using both scaling laws and finite element models.

• T. Tortschanoff
  
• R. Burgmer, H.-U. Klein, D. Krischel, B. Schellong, P. Schmidt
  ACCEL, Bergisch Gladbach
• M. Durante, A. Payn, J.-M. Rifflet, F. Simon
  CEA, Gif-sur-Yvette
• M. Modena, Y. Papaphilippou, L. Rossi, K. M. Schirm
  CERN, Geneva

• E. Y. Wildner
  
• M. Bajko, P. Bestmann, S. D. Fartoukh, J. B. Jeanneret, D. P. Missiaen, D. Tommasini
  CERN, Geneva

• E. Y. Wildner
  
• N. Emelianenko
  CERN, Geneva

• E. Y. Wildner
  
• C. Vollinger
  CERN, Geneva

• S. A. Kahn
  
• M. Alsharo'a, R. P. Johnson
  Muons, Inc, Batavia
• V. Kashikhin, V. S. Kashikhin, K. Yonehara, A. V. Zlobin
  Fermilab, Batavia, Illinois

A helical cooling channel consisting of a pressurized gas absorber imbedded in a magnetic channel that provides superimposed solenoidal, helical dipole and helical quadrupole fields has shown considerable promise in providing six-dimensional cooling of muon beams. The analysis of this muon cooling technique with both analytic and simulation studies has shown significant reduction of muon phase space. A particular channel that has been simulated is divided into four segments each with progressively stronger fields and smaller apertures to reduce the equilibrium emittance so that more cooling can occur. The fields in the helical channel are sufficiently large that the conductor for segments 1 and 2 can be Nb3Sn and the conductor for segments 3 and 4 may need to be high temperature superconductor. This paper will describe the magnetic specifications for the channel and two conceptual designs on how to implement the magnetic channel.

• D. J. Harding
  
• J. DiMarco, C. C. Drennan, V. S. Kashikhin, S. Kotelnikov, J. R. Lackey, A. Makarov, A. Makulski, R. Nehring, D. F. Orris, E. Prebys, P. Schlabach, G. Velev, D. G.C. Walbridge
  Fermilab, Batavia, Illinois

To better control the beam position, tune, and chromaticity in the Fermilab Booster synchrotron, a new package of six corrector elements has been designed, incorporating both normal and skew orientations of dipole, quadrupole, and sextupole magnets. The devices are under construction and installation at 48 locations is planned. The density of elements and the rapid slew rate have posed special challenges. The magnet construction is presented along with DC measurements of the magnetic field.

• V. S. Kashikhin
  
• R. P. Johnson, S. A. Kahn, T. J. Roberts
  Muons, Inc, Batavia
• V. Kashikhin, M. J. Lamm, G. Romanov, K. Yonehara, A. V. Zlobin
  Fermilab, Batavia, Illinois

MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a Helical Cooling Channel (HCC) for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components which diminish as the beam loses energy as it slows down in a liquid helium absorber inside the magnets. Two superconducting magnet system designs are described which use quite different approaches to providing the needed fields. Additional magnets that provide emittance matching between the HCC and upstream and downstream spectrometers are also described as are the results of G4Beamline simulations of the beam cooling behaviour of the complete magnet and absorber system.

• V. Kashikhin
  
• A. V. Zlobin
  Fermilab, Batavia, Illinois

After LHC operates for several years at nominal parameters it will need an upgrade to higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is a straightforward step in this direction. One of the approaches being considered for the new LHC IRs is a "dipole-first: option with two separation dipoles placed in front of the focusing quadrupoles. It reduces the number of parasitic collisions with respect to the "quadrupole-first" option and allows independent field error corrections for each beam. Most of key magnet designs for the "dipole-first" option including high-field large-aperture dipoles (D1) and 2-in-1 quadrupoles have already been studied and reported. This paper focuses on design studies of the 2-in-1 separation dipole (D2) located between D1 and the quadrupoles. High operation field of the same polarity in large adjacent apertures imposes limitations on the maximum field, field quality and mechanics for this magnet. This paper analyses possible D2 magnet designs based on Nb3Sn superconductor and compares them in terms of the aperture size, maximum field, field quality and Lorents forces in the coil.

• E. Prebys
  
• C. C. Drennan, D. J. Harding, V. S. Kashikhin, J. R. Lackey, A. Makarov, W. Pellico
  Fermilab, Batavia, Illinois

The Fermilab neutrino program places unprecedented demands on the lab's 8 GeV Booster synchrotron, which has not changed significantly since it was built almost 35 years ago. In particular, the existing corrector system is not adequate to control beam position and tune throughout the acceleration system, and provides limited compensation for higher order resonances. We present an ambitious ongoing project to build and install a set of 48 corrector packages, each containing horizontal and vertical dipoles, normal and skew quadrupoles, and normal and skew sextupoles. Space limitations in the machine have motivated a unique design, which utilizes custom wound coils around a 12 pole laminated core. Each of the 288 discrete multipole elements in the system will have a dedicated power supply, the output current of which is controlled by an individual programmable ramp. This provides for great flexibility in the system, but also presents a challenge in terms of designing the control hardware and software in such a way that the system can be operated in the most efficacious way.

• I. Terechkine
  
• V. Kashikhin, T. M. Page, M. Tartaglia, J. C. Tompkins
  Fermilab, Batavia, Illinois

• G. Velev
  
• J. DiMarco, D. J. Harding, V. S. Kashikhin, M. J. Lamm, P. Schlabach, M. Tartaglia, J. C. Tompkins
  Fermilab, Batavia, Illinois

A method for measurement of rapidly changing magnetic fields has been developed and applied to the testing of new room temperature corrector packages designed for the Fermilab Booster Synchrotron. The method is based on fast digitization of a slowly rotating tangential coil probe, with analysis combining the measured coil voltages across a set of successive magnet current cycles. This paper presents results on the field quality measured for normal and skew dipole, quadrupole, and sextupole magnets in several of these corrector packages.

• A. V. Zlobin
  
• G. Ambrosio, N. Andreev, E. Barzi, R. Bossert, R. H. Carcagno, G. Chlachidze, J. DiMarco, SF. Feher, V. Kashikhin, V. S. Kashikhin, M. J. Lamm, A. Nobrega, I. Novitski, D. F. Orris, Y. M. Pischalnikov, P. Schlabach, C. Sylvester, M. Tartaglia, J. C. Tompkins, D. Turrioni, G. Velev, R. Yamada
  Fermilab, Batavia, Illinois

Accelerator magnets based on Nb3Sn superconductor advances magnet operation fields above 10T and increases the coil temperature margin. Development of a new accelerator magnet technology includes the demonstration of main magnet parameters (maximum field, quench performance, field quality, etc.) and their reproducibility using short models, and then the demonstration of technology scale up using long coils. Fermilab is working on the development of Nb3Sn accelerator magnets using shell-type dipole coils and react-and-wind method. As a part of the first phase of technology development Fermilab built and tested six 1-m long dipole models and several dipole mirror configurations. The last three dipoles and two mirrors reached their design fields of 10^-11 T. Reproducibility of magnet field quality was demonstrated by all six short models. The technology scale up phase has started by building 2m and 4m dipole coils and testing them in a mirror configuration. This effort complements the Nb3Sn scale up work being performed in the framework of US LHC Accelerator Research Program (LARP). The status and main results of the Nb3Sn accelerator magnet development at Fermilab are reported.

• C. Wu
  
• E. Abed, G. Bai, B. L. Beaudoin, S. Bernal, I. Haber, R. A. Kishek, P. G. O'Shea, M. Reiser, D. Stratakis, D. F. Sutter, K. Tian, M. Walter
  UMD, College Park, Maryland

Beam based alignment and control has been a critical issue for many accelerators. In this paper, we've developed a new approach that can correct the beam orbit using a systematic quad-scan method, where there is an insufficient number of beam position monitors. In this approach, we've proposed a calibrated response matrix. This matrix takes consideration of the different sensitivities of different quadrupoles in the lattice. With the calibrated response matrix, we can greatly enhance our ability to control the beam centroid motion and reduce the control effort.

• P. M. McIntyre
  
• A. D. McInturff, A. Sattarov
  Texas A&M University, College Station, Texas

The block coil geometry utilized in recent high-field dipole development has significant benefit for applications requiring rapid cycling, since it intrinsically suppresses coupling currents between strands. A conceptual design for a 6 Tesla dipole has been studied for such applications, in which the intra-strand losses are minimized by using bronze-process Nb3Sn superconducting wire developed for ITER. That conductor provides isolated fine filaments and optimum matrix resistance between filaments. The block-coil geometry further accommodates placement of He cooling channels inside the coil, so that heat from radiation and from AC losses can be removed with minimum temperature rise in the coil. The design could be operated with supercritical helium cooling, and should make it possible to operate with a continuous ramp rate of 5-10 T/s.

• V. Popov
  
• M. D. Busch, S. M. Hartman, S. F. Mikhailov, O. Oakeley, P. W. Wallace, Y. K. Wu
  FEL/Duke University, Durham, North Carolina

A booster synchrotron has been recently commissioned at Duke University as part of the High Intensity Gamma-ray Source (HIGS) upgrade. All dipole and quadrupole magnets are fed by the same power supply in order to facilitate synchronization. A 500kW retired thyristor controlled power supply has been completely rebuilt to provide high accuracy ramping of current in the range between 150A and 700A in a 1.3 sec repetition cycle. Reproducibility of current at extraction energy is better than 0.1% for entire operational range of energy. Conflict of a fast ramping operation and a magnet protection in the case of emergency shutdown was resolved using additional thyristor switches. All trim power supplies involved in ramp have been matched with the main power supply for the time response and voltage range. The injection and extraction schemes require rapidly ramping Y-correctors. The required peak power about 4 kW in these correctors is provided by a combining a low voltage DC power supply and a pulse boosting circuit. We present the challenges of designing and developing booster power supply system. And also we report measured performance and operational experience in this paper.

• C. Goodzeit
  
• M. J. Ball, R. B. Meinke
  Advanced Magnet Lab., Inc, Melbourne, Florida

This work is partially supported under U. S. Department of Energy grant : DoE SBIR DE-FG02-06ER 84492

• A. C. de Lira
  
• P. Bellomo, K. Luchini, D. Macnair
  SLAC, Menlo Park, California

The LCLS injector at SLAC requires 100+ dc-magnet power supply systems for its operation. Power supplies are divided into two main groups: intermediate rack-mounted type for output powers up to 20 kW at 375 A, and bipolar units rated 6 A, 12 A, and 30 A for corrector magnets and small quadrupoles. The intermediate power supplies are controlled by a 20-bit Ethernet power supply controller, specially developed at SLAC to be used in this project. The bipolar units are controlled via 12-bit DACs and ADCs housed in a VME crate. EPICS is the controls interface to all systems. For all systems, stability requirements are better than 10⁰⁰ ppm. The Power Conversion Department at SLAC, in close cooperation with the LCLS Controls group, was responsible for defining the major characteristics of the power supply systems, their specification, procurement, installation, and commissioning. In this paper we describe the main characteristics of the power supply systems for the LCLS injector, including results from their successful commissioning early this year.

• G. H. Biallas
  
• N. T. Belcher
  The College of William and Mary, Williamsburg
• D. Douglas, T. Hiatt, K. Jordan
  Jefferson Lab, Newport News, Virginia

Two styles of Panofsky Quadrupoles with integral corrector dipole windings are in use in the electron beam line of the Free Electron Laser at Jefferson Lab. We combined the functions into single magnets, adding hundreds of Gauss-cm dipole corrector capability to existing quadrupoles because space is at a premium along the beam line. Superposing high quality dipole corrector field on a high quality, weak (600 to 1'000 Gauss) quadrupole is possible because the parallel slab iron yoke of the Panofsky Quadrupole acts as a window frame style dipole yoke. The dipole field is formed when two current sources, designed and made at Jlab, add and subtract current from the two opposite quadrupole current sheet windings parallel to the dipole field direction. The current sources also drive auxiliary coils at the yoke's inner corners that improve the dipole field. Magnet measurements yielded the control system field maps that characterize the two types of fields. Details of field analysis using OPERA, construction methods, wiring details, magnet measurements and the current sources are presented.

• D. Bruno
  
• G. Ganetis, G. Heppner, W. Louie, J. Sandberg, C. Schultheiss
  BNL, Upton, Long Island, New York

The two rings in the Relativistic Heavy Ion Collider (RHIC) require a total of 933 power supplies to supply current to highly inductive superconducting magnets. Failure statistics for the RHIC power supplies will be presented for the last three RHIC runs. The failures of the power supplies will be analyzed. The statistics associated with the power supply failures will be presented. Comparisons of the failure statistics for the last three RHIC runs will be shown. Improvements that have increased power supply availability will be discussed. Further improvements to increase the availability of the power supplies will also be discussed.

• W. Meng
  
• G. Ganetis, A. K. Jain, D. Kayran, V. Litvinenko, C. Longo, G. J. Mahler, E. Pozdeyev, J. E. Tuozzolo
  BNL, Upton, Long Island, New York

In this paper we describe unique features of magnets for R&D ERL, which is under construction in Collider-Accelerator Department, BNL. The R&D ERL serves as a test-bed future BNL ERLs, such as electron-cooler-ERL for RHIC and 20 GeV ERL for future electron-hadron, eRHIC. We present selected designs of various dipole and quadrupole magnets, which are used in Z-bend merging systems and the returning loop, 3-D simulations of the fields in these magnets, particle tracking and analysis of magnet's influence on the beam parameters. We discuss an uncommon method of setting requirements on the quality of magnetic field and transferring them into measurable parameters as well as into manufacturing tolerances. We compare selected simulation with results magnetic measurements.

• W. Zhang
  
• I. Marneris, J. Sandberg
  BNL, Upton, Long Island, New York

Large accelerator main magnet system consists of hundreds, even thousands, of dipole magnets. They are linked together under selected configurations to provide highly uniform dipole fields when powered. Distributed capacitance, insulation resistance, coil resistance, magnet inductance, and coupling inductance of upper and lower pancakes make each magnet a complex network. When all dipole magnets are chained together in a circle, they become a coupled pair of very high order complex ladder networks. In this study, a network of more than thousand inductive, capacitive or resistive elements are used to model an actual system. The circuit is a large scale network. Its equivalent polynomial form has several hundred degrees. Analysis of this high order circuit and simulation of the response of any or all components is often computationally infeasible. We present methods to use frequency decomposition approach to effectively simulate and analyze magnet configuration and power supply topologies.

• W. Zhang
  
• I. Marneris, J. Sandberg
  BNL, Upton, Long Island, New York

A main magnet chain forms a pair of transmission lines. Pulse-reflection-caused voltage and current differentiation throughout the magnet chain can have adverse effect on main magnet field quality. This effect is associated with magnet system configuration, coupling efficiency, and parasitic parameters. A better understanding of this phenomenon will help us in new design and existing system upgrade. In this paper, we exam the transmission line effect due to different input functions as well as configuration, coupling, and other parameters.

• F. Zimmermann
  

The EU CARE-HHH and US-LARP programmes for an LHC upgrade aim at increasing the LHC luminosity by a factor of 10 around the year 2015. The upgrade plan envisages rebuilding the interaction regions (IRs) and modifying the beam parameters. In addition to advanced low-beta quadrupoles, the future IRs may accommodate other novel elements such slim s.c. dipoles or quadrupoles embedded deep inside the detectors, global low-angle crab cavities, and wire compensators of long-range beam-beam effects. Important constraints on the upgrade path are the maximum acceptable number of detector pile-up events, favoring many closely spaced bunches, and the heat load on the cold-magnet beam screens, pointing towards fewer and more intense bunches. In addition, the upgrade of the LHC ring proper should be complemented by an upgrade of the injector complex. I will present preferred luminosity upgrade scenarios for the LHC IRs and beam parameters, sketch accompanying injector enhancements, and comment on a longer-term LHC energy upgrade.

• X. Huang
  
• S.-Y. Lee
  IUCF, Bloomington, Indiana
• K. Y. Ng
  Fermilab, Batavia, Illinois

We systematically measured the emittance evolution of a fast cycling proton accelerator on a turn-by-turn basis under various beam intensities via an ionization profile monitor (IPM). The vertical emittance growth rate was derived and phenomenologically analyzed. The transverse and longitudinal components in the horizontal beam size were separated by making use of their different evolution behaviors. The quadrupole mode beam size oscillation after transition crossing is also studied and explained. We found a considerable space-charge-induced emittance growth rate component in the vertical plane but not as much for the horizontal plane. We carried out multiparticle simulations to understand the mechanism of space-charge-induced emittance growth. The major sources of emittance growth were found to be the random skew-quadrupole and dipole field errors in the presence of large space-charge tune spread.

PRSTAB 9, 014202 (2006)

• P. Emma
  
• K. L.F. Bane, Y. T. Ding, J. C. Frisch, Z. Huang, H. Loos, G. V. Stupakov, J. Wu
  SLAC, Menlo Park, California
• E. Prat
  DESY, Hamburg
• F. Sannibale, K. G. Sonnad, M. S. Zolotorev
  LBNL, Berkeley, California

The Linac Coherent Light Source (LCLS) is a SASE x-ray free-electron laser project presently under construction at SLAC. The injector section from RF photocathode gun through the first bunch compressor chicane was installed during the Fall of 2006. The first bunch compressor chicane is located at 250 MeV and nominally compresses a 1-nC electron bunch from an rms length of about 1 mm to 0.2 mm. The degree of compression is highly adjustable using RF phasing and also chicane magnetic field variations. Transverse phase space and bunch length diagnostics are located immediately after the chicane. We present measurements and simulations of the longitudinal and transverse phase space after the chicane in various beam conditions, including extreme compression where coherent radiation effects are expected to be striking.

• Z. Li
  
• V. Akcelik, A. E. Candel, L. Ge, A. C. Kabel, K. Ko, L. Lee, C.-K. Ng, E. E. Prudencio, G. L. Schussman, R. Uplenchwar, L. Xiao
  SLAC, Menlo Park, California

Under the support of the U. S. DOE SciDAC program, SLAC has been developing a suite of 3D parallel finite-element codes aimed at high-accuracy, high-fidelity electromagnetic and beam physics simulations for the design and optimization of next-generation particle accelerators. Running on the latest supercomputers, these codes have made great strides in advancing the state of the art in applied math and computer science at the petascale that enable the integrated modeling of electromagnetics, self-consistent Particle-In-Cell (PIC) particle dynamics as well as thermal, mechanical, and multi-physics effects. This paper will present 3D results of trapped mode calculations in an ILC cryomodule and the modeling of the ILC Sheet Beam klystron, shape determination of superconducting RF (SCRF) cavities and multipacting studies of SCRF HOM couplers, as well as 2D and preliminary 3D PIC simulation results of the LCLS RF gun.

• E. G. Stern
  
• J. F. Amundson, P. Spentzouris, A. Valishev
  Fermilab, Batavia, Illinois
• J. Qiang, R. D. Ryne
  LBNL, Berkeley, California

• L. O. Dallin
  
• D. Bodnarchuk, T. Summers
  CLS, Saskatoon, Saskatchewan

• G. Wuestefeld
  
• R. Follath, A. Meseck
  BESSY GmbH, Berlin

The cascaded High Gain Harmonic Generation (HGHG) scheme proposed for the BESSY-FEL contains an inherent potential for providing jitter free radiation pulses for pump and probe experiments. In an HGHG stage an energy modulation is imprinted to the electron beam by a seeding radiation. A dispersive section converts this energy modulation to a spatial modulation which is optimized for a particular harmonic. The subsequent radiator is optimized for this harmonics and generates radiation with high power which is used as seeding radiation for the next stage. After passage through the modulator, the seeding radiation become redundant and can be separated from the prebunched electrons using a deflecting dispersive chicane. This radiation and the final FEL output will have a fixed temporal separation as the first one is the driving seeding radiation for the second one. Using the planned test facility for HGHG scheme at BESSY as an example, we present simulation studies for a sequences of two jitter free pump and probe pulses including the deflecting chicane and a suitable beam line.

• J. S. Sekutowicz
  
• M. Ferrario
  INFN/LNF, Frascati (Roma)
• J. Iversen, D. Klinke, D. Kostin, W.-D. Moller, A. Muhs
  DESY, Hamburg
• P. Kneisel
  Jefferson Lab, Newport News, Virginia
• K. Ko, Z. Li, L. Xiao
  SLAC, Menlo Park, California
• R. S. Lefferts, A. R. Lipski
  SBUNSL, Stony Brook, New York
• T. Rao, J. Smedley
  BNL, Upton, Long Island, New York
• P. Strzyzewski
  The Andrzej Soltan Institute for Nuclear Studies, Centre Swierk, Swierk/Otwock

• S. Khan
  
• G. Angelova, V. G. Ziemann
  UU/ISV, Uppsala
• J. Boedewadt, A. Winter
  Uni HH, Hamburg
• M. Hamberg, N. X. Javahiraly, M. Larsson, P. Salen, P. van der Meulen
  FYSIKUM, AlbaNova, Stockholm University, Stockholm
• A. Meseck
  BESSY GmbH, Berlin
• E. Saldin, H. Schlarb, B. Schmidt, E. Schneidmiller, M. V. Yurkov
  DESY, Hamburg

* E. Saldin, E. Schneidmiller, M. Yurkov, NIM A 539 (2005), 499

• M. Svandrlik
  
• S. Bassanese, A. Carniel, K. Casarin, D. Castronovo, P. Craievich, G. D'Auria, R. De Monte, P. Delgiusto, S. Di Mitri, A. Fabris, R. Fabris, M. Ferianis, F. Giacuzzo, F. Iazzourene, G. L. Loda, M. Lonza, F. M. Mazzolini, D. M. Molaro, G. Pangon, C. Pasotti, G. Penco, L. Pivetta, L. Rumiz, C. Scafuri, G. Tromba, A. Vascotto, R. Visintini, D. Zangrando
  ELETTRA, Basovizza, Trieste
• L. Picardi, C. Ronsivalle
  ENEA C. R. Frascati, Frascati (Roma)

• M. Sawamura
  
• T. Furuya, S. Sakanaka, T. Suwada, T. Takahashi, K. Umemori
  KEK, Ibaraki
• H. Sakai, K. Shinoe
  ISSP/SRL, Chiba

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

• D. Einfeld
  
• M. Belgroune, G. Benedetti, M. L. Lopes, J. Marcos, M. Munoz, M. Pont
  ALBA, Bellaterra (Cerdanyola del Valles)

• C.-C. Kuo
  
• H.-P. Chang, H. C. Chao, P. J. Chou, W. T. Liu, G.-H. Luo, H.-J. Tsai, M.-H. Wang
  NSRRC, Hsinchu

• V. Sajaev
  
• M. Borland, A. Xiao
  ANL, Argonne, Illinois

APS has recently held a round of discussions on upgrade options for the APS storage ring. Several options were discussed that included both storage ring and energy-recovery linac options. Here we present a storage ring lattice that fits into the APS tunnel and has a number of significant improvements over the existing storage ring. The present APS lattice has 40-fold symmetry with each sector having one 5-m-long straight section for insertion device (ID) placement. Each sector also provides one beamline for radiation from the bending magnet. The upgrade lattice preserves locations of the existing insertion devices but provides for increased ID straight section length to accommodate 8-m-long insertion devices. This lattice also decreases emittance by a factor of two down to 1.6 nm rad. And last but not least, it provides two additional 2.1-m-long ID straight sections per sector with one of these straight sections being parallel to the existing bending magnet beamline. We also present dynamic aperture optimization, lifetime calculations, and other nonlinear-dynamics-related simulations.

• N. Sereno
  
• M. Borland, H. W. Friedsam
  ANL, Argonne, Illinois

In the recent past, the Advanced Photon Source (APS) was asked by the U. S. Department of Energy to explore a revolutionary upgrade based on emerging energy recovery linac (ERL) technology. In an ERL, the energy of the 7-GeV, 100-mA beam is recovered after the beam passes through user beamlines by decelerating the beam back through the same superconducting linac cavities that accelerated it. The main constraint on this upgrade is that the existing APS beamlines not be disturbed. This requires that the APS storage ring be used as a single-pass transport line in the overall ERL beamline layout. A natural place to locate the ERL is inside the existing APS storage ring ‘‘infield'' area, which has unoccupied space south of the existing APS injector complex. Other important constraints include minimal disturbance of existing building structures and injector beamlines. The existing injector complex would be preserved so that existing operation can be continued through and even possibly beyond ERL commissioning. In this paper, we describe a layout that satisfies these constraints. We also estimate the amount of emittance increase the beam will experience before ring injection.

• G. J. Waldschmidt
  
• R. M. Lill, L. H. Morrison
  ANL, Argonne, Illinois

A high-resolution X-band cavity beam position monitor (BPM) has been developed for the LCLS in order to achieve micron-level accuracy of the beam position using a dipole mode cavity and a monopole mode reference cavity. The rf properties of the BPM will be discussed in this paper including output power, tuning, and issues of manufacturing. In addition, methods will be presented for improving the isolation of the output ports to differentiate between horizontal/vertical beam motion and to reject extraneous modes from affecting the output signal. The predicted simulation results will be compared to data collected from low-power experimental tests.

• G. Andonian
  
• R. B. Agustsson, A. M. Cook, M. P. Dunning, E. Hemsing, A. Y. Murokh, S. Reiche, J. B. Rosenzweig
  UCLA, Los Angeles, California
• M. Babzien, K. Kusche, R. Malone, V. Yakimenko
  BNL, Upton, Long Island, New York

• J. D.A. Smith
  
• C. J. Glasman
  UMAN, Manchester

* C. Beard and R. M. Jones, EUROTeV-Report-2006-103** C. Beard and J. Smith, EPAC06 Proc. MOPLS070

• S. R. Koscielniak
  
• C. Johnstone
  Fermilab, Batavia, Illinois

The linear-field non-scaling FFAG lattices originally proposed for multi-GeV muon acceleration are now being modified for application to order 100 MeV/u proton or carbon medical applications. The momentum range is large and the chromatic tune variation is significant. In the medical case, the time of flight variation is immaterial but the issue of resonance crossing is more acute owing to the much lower rate of energy gain. Magnets with non-normal entry/exit faces are considered as means to reduce the tune variation. Thus one is motivated to study fringe fields and their effects. We make a brief study of dipole and quadrupole magnets with normal and rotated entry/exit faces. For the artificial case of a cosine-squared fall off in the quadrupole field, analytic results are obtained which though approximate are superior to numerical integration. This property is achieved by insisting that the error in the equation of motion is zero and the determinant is unity at the entry, exit and centre of the fringe field.

• P. J. Spiller
  
• U. B. Blell, H. Eickhoff, E. Fischer, E. Floch, P. Hulsmann, J. E. Kaugerts, M. Kauschke, H. Klingbeil, H. G. Koenig, A. Kraemer, D. Kramer, U. Laier, G. Moritz, C. Omet, N. Pyka, H. Ramakers, H. Reich-sprenger, M. Schwickert, J. Stadlmann
  GSI, Darmstadt
• A. D. Kovalenko
  JINR, Dubna, Moscow Region

• J. Stadlmann
  
• K. Blasche, B. Franczak, F. Hagenbuck, C. Omet, N. Pyka, S. Ratschow, P. J. Spiller
  GSI, Darmstadt
• A. D. Kovalenko
  JINR, Dubna, Moscow Region

• R. Tolle
  
• T. Bergmark, S. Johnson, T. Johnson, T. Lofnes, G. Norman, T. Peterson
  Uppsala University, Uppsala
• K. Bongardt, J. Dietrich, F. M. Esser, O. Felden, R. Greven, G. Hansen, F. Klehr, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, A. Raccanelli, M. Schmitt, Y. Senichev, E. Senicheva, R. Stassen, H. Stockhorst
  FZJ, Julich
• B. Gålnander, D. Reistad
  TSL, Uppsala
• F. Hinterberger
  Universität Bonn, Helmholtz-Institut für Strahlen- und Kernphysik, Bonn
• K. Rathsman
  UU/ISV, Uppsala
• M. Steck
  GSI, Darmstadt

• S. Tomassini
  
• D. Alesini, A. Beatrici, A. Clozza, E. Di Pasquale, G. Fontana, F. Marcellini, G. Mazzitelli, M. Paris, P. Raimondi, C. Sanelli, G. Sensolini, F. Sgamma, M. Troiani, M. Zobov, A. Zolla
  INFN/LNF, Frascati (Roma)
• M. E. Esposito
  Rome University La Sapienza, Roma

* DAPHNE Upgrade Team, "DAPHNE Upgrade for Siddharta run", DAPHNE Tech. Note G-68, Dec. 2006.

• M. DiCastro
  
• L. Bottura, L. Deniau, N. J. Sammut, S. Sanfilippo, D. Sernelius, W. Venturini Delsolaro
  CERN, Geneva

• W. J.M. Weterings
  
• G. Bellodi, J. Borburgh, T. Fowler, F. Gerigk, B. Goddard, K. Hanke, M. Martini, L. Sermeus
  CERN, Geneva

• N. M. Gelfand
  

Measurements of the tune on the front porch of the Tevatron* showed a drift of the tune which tracked the time dependence of the sextupole moment in the dipoles. Calculations using survey data to calculate the closed orbit failed to reproduce the observed tune shifts. The feed down of these sextupole moments generates a quadrupole field at the ends of the dipoles. It is suggested, based on calculations, that the change in the sextupole moment of the dipoles also produces a change in the strength of the strength of the zero length quadrupole incorporated in the end of the dipoles and that this change can account for the observed tune drifts.

*Tevatron Chromaticity and Tune Drift and Snapshot Studies Report, G. Annala, P. Bauer, M. Martens, D. Still, G. Velev, Beams-doc-1236 (Jan. 5,2005)

• D. E. Johnson
  
• A. Z. Chen, I. Rakhno
  Fermilab, Batavia, Illinois

A 8 GeV H^- superconducting linac has been proposed as an alternative injector for the Main Injector to support a 2 MW Neutrino program. An injection absorber is required to accept protons generated after the secondary stripping foil which will intercept the un-stripped H^- and H0 particles after the MI primary foil injection point. The motivations underlying the choice of a compact internal absorber over an external absorber will be discussed. We show that using a high-Z material (tungsten) for the inner shielding allows the construction a compact absorber that can take a very intense beam and fits within the existing enclosure. The absorber requirements and a shielding design and the results of energy deposition calculations are presented.

• D. E. Johnson
  
• J. Beebe-Wang, C. J. Liaw, D. Raparia
  BNL, Upton, Long Island, New York

The technique for H^- charge exchange for multi-turn injection utilizing stripping foils in the energy range of a few hundred MeV has been used at many labs for decades and most recently up to 1 GeV at the SNS. Utilization the beam from the proposed Proton Driver* would permit the extension of this technique up to 8 GeV. The injection layout and required accelerator modifications are discussed. Results from transverse and longitudinal simulations are presented.

* W. G. Foster and J. A. MacLachlan, "A Multi-mission 8 GeV Injector Linac as a Fermilab Booster Replacement", Proc. Of LINAC-2002, Gyeongju, Korea, p.86.

• V. D. Shiltsev
  
• T. Kroyer, R. de Maria
  CERN, Geneva

• M. Walter
  
• G. Bai, B. L. Beaudoin, S. Bernal, D. W. Feldman, T. F. Godlove, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, M. Reiser, D. Stratakis, D. F. Sutter, J. C.T. Thangaraj, C. Wu
  UMD, College Park, Maryland

The University of Maryland Electron Ring (UMER) is a low energy, high current recirculator for beam physics research. The electron beam current is adjustable from 0.7 mA, an emittance dominated beam, to 100 mA, a strongly space charge dominated beam. UMER is addressing issues in beam physics relevant to many applications that require intense beams of high quality such as advanced concept accelerators, free electron lasers, spallation neutron sources, and future heavy-ion drivers for inertial fusion. The primary focus of this presentation is experimental results and improvements in multi-turn operation of the electron ring. Transport of a low current beam over 100 turns (3600 full lattice periods) has been achieved. Results of high current, space charge dominated multi-turn transport will also be presented.

• M. Walter
  
• G. Bai, B. L. Beaudoin, S. Bernal, D. W. Feldman, T. F. Godlove, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, M. Reiser, D. Stratakis, D. F. Sutter, J. C.T. Thangaraj, C. Wu
  UMD, College Park, Maryland

The University of Maryland Electron Ring (UMER) is a low energy, high current recirculator for beam physics research. The electron storage ring has been closed and recent operations have been focused on achieving multi-turn transport. An entire suite of terminal diagnostics is available for time-resolved phase space measurements of the beam. These diagnostics have been mounted and tested at several points on the ring before it was closed. UMER utilizes a unique injection scheme which uses the fringe fields of an offset quadrupole to assist a pulsed dipole in bending the beam into the ring. Similar concepts, along with more traditional electrostatic methods, are being considered for beam extraction. This presentation will focus on the recent efforts to design and deploy these major subsystems required for beam extraction.

• I. Baek
  
• G. Bollen, M. Hausmann, D. Lawton, R. M. Ronningen, A. Zeller
  NSCL, East Lansing, Michigan

To support pre-conceptual research and development for rare isotope beam production via projectile fragmentation at the Rare-Isotope Accelerator facility or similar next-generation exotic beam facilities, the interactions between primary beams and beryllium and liquid-lithium production targets in the fragment pre-separator area were simulated using the Monte-Carlo radiation transport code PHITS. The purpose of this simulation is to determine the magnitude of the radiation fields in the pre-separator area so that levels of hadron flux and energy deposition can be obtained. It was of particular interest to estimate the maximum radiation doses to magnet coils and other components such as the electromagnetic pump for a liquid-lithium loop, and to estimate component lifetimes. We will show a detailed geometry of the pre-separator area developed for these simulations. We will provide verification that trajectories of beams and fragments when transported in the PHITS simulations agree with results from standard ion-optics calculations. We will present estimates of radiation doses to pre-separator components and give estimates for component lifetimes.

• L. Wang
  
• F. Zimmermann
  CERN, Geneva

The ILC positron damping ring comprises hundreds of meters of wiggler sections, where many more photons than in the arcs are emitted, and with the smallest beam-pipe aperture of the ring. A significant electron-cloud density can therefore be accumulated via photo-emission and via beam-induced multipacting. In field-free regions the electron-cloud build up may be suppressed by adding weak solenoid fields, but the electron cloud remaining in the wigglers as well as in the arc dipole magnets can still drive single-bunch and multi-bunch beam instabilities. This paper studies the electron-cloud formation in an ILC wiggler section for various scenarios, as well as its character, and possible mitigation schemes.

• B. Han
  
• M. P. Stockli
  ORNL, Oak Ridge, Tennessee

Beam envelope calculations show that a solenoid-drift-(singlet quad)-(sector dipole)-(singlet quad)-drift-solenoid LEBT allows for transporting 65-kV, high-current H^- beams with smaller beam radii than the initially-explored (doublet quad)-drift-(double-focusing dipole)-drift-solenoid configuration. In addition, it appears that the new configuration is more robust because it allows for perfect matching of the final beam parameters for broad ranges of the parameters describing the lattice and the input beam. Such a LEBT with a dipole (switching-) magnet is required to assure meeting the 99% ion source availability requirement after upgrading the power of the Spallation Neutron Source. The SNS power upgrade will roughly double the neutron flux by increasing the proton beam energy from 1 to 1.3 GeV and by increasing the LINAC beam peak current from 38 to 59 mA. Because the RFQ losses increase with beam current and emittance, the RFQ input current needs to be increased from 41 to 67 mA if the normalized emittance can be maintained at 0.2 mm-mrad, or to 95 mA if the emittance increases to 0.35 mm-mrad.

• M. Bai
  
• A. U. Luccio, Y. Makdisi, P. H. Pile, T. Roser
  BNL, Upton, Long Island, New York

Full spin flip in the presence of full Siberian snake has been achieved by using an rf dipole or solenoid as spin flipper at IUCF and COSY. This technique requires one to change the snake configuration to move the spin tune away from half integer. However, this is not practical for an operational high energy polarized proton collider like RHIC where beam lifetime is sensitive to small betatron tune change. An new technique of achieving full spin flip with the spin tune staying at half integer is proposed. This paper presents the design of RHIC spin flipper along with simulation results.

• Y. Luo
  
• P. Cameron, A. Della Penna, T. Satogata, D. Trbojevic
  BNL, Upton, Long Island, New York

A beam-based method was proposed and applied to check the polarities of the arc sextupoles in the Relativistic Heavy Ion Collider (RHIC) with repetitive local horizontal bumps. Wrong sextupole polarities can be easily identified from mismatched signs and amplitudes of the horizontal and vertical tune shifts from bump to bump and/or from arc to arc. This check takes less than 2 hours for both RHIC Blue and Yellow rings. Tune shifts in both planes during this study were tracked with a high-resolution baseband tunemeter (BBQ) system. This method was successfully used to the sextupole polarity check in the RHIC run06.

• C.-F. Wu
  
• S. Dong, X. D. He, H. Lin, L. Wang
  USTC/NSRL, Hefei, Anhui

Some model cavities have been further developed and investigated for a X-band (f=9.37GHz) hybrid dielectric-iris-loaded accelerating structure based on the calculated results about the effect of the dimension tolerance on the RF properties. The dispersion curve fitted by using the measurement value is consistent with the one calculated. The r/Q values of the dipole modes have been calculated by the Mafia code. The theoretical results show that the r/Q values of dipole modes for the new accelerating structure are lower than those for the iris-load accelerating structure.

• P. Goudket
  
• C. D. Beard, P. A. McIntosh
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• G. Burt
  Cockcroft Institute, Lancaster University, Lancaster
• N. Chanlek, R. M. Jones
  UMAN, Manchester
• A. C. Dexter
  Cockcroft Institute, Warrington, Cheshire

In order to verify detailed impedance simulations, the modes in an aluminium model of the ILC crab cavity were investigated using a bead-pulling technique as well as a stretched-wire frequency domain measurement. The combination of these techniques allow for a comprehensive study of the modes of interest. For the wire measurement, a transverse alignment system was fabricated and rf components were carefully designed to minimize any potential impedance mismatches. The measurements are compared with direct simulations of the stretched-wire experiments using numerical electromagnetic field codes. High impedance modes of particular relevance to the ILC crab cavity are identified and characterized

• G. Burt
  
• C. D. Beard, P. Goudket, P. A. McIntosh
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• L. Bellantoni
  Fermilab, Batavia, Illinois
• R. G. Carter, A. C. Dexter, R. O. Jenkins
  Cockcroft Institute, Lancaster University, Lancaster

The ILC crab cavity will require the design of an appropriate power coupler. The beamloading in dipole cavities is considerably more variable than accelerating cavities, hence simulations have been performed to establish the required external Q. Simulations of a suitable coupler were then performed and were verified using a normal conducting prototype with variable coupler tips.

• I. R.R. Shinton
  
• R. M. Jones
  Cockcroft Institute, Warrington, Cheshire

• T. N. Khabiboulline
  
• I. G. Gonin, N. Solyak
  Fermilab, Batavia, Illinois

• Z. Li
  
• L. Ge, K. Ko, L. Lee, C.-K. Ng, G. L. Schussman, L. Xiao
  SLAC, Menlo Park, California
• T. Higo, Y. Morozumi, K. Saito
  KEK, Ibaraki
• P. Kneisel
  Jefferson Lab, Newport News, Virginia
• J. S. Sekutowicz
  DESY, Hamburg

The Low-Loss shape cavity design has been proposed as a possible alternative to the baseline TESLA cavity design for the ILC. The advantages of this design over the TESLA cavity are its lower cryogenic loss, and higher achievable gradient due to lower surface fields. High gradient prototypes for such designs have been tested at KEK (ICHIRO) and JLab (LL). However, issues related to HOM damping and multipacting (MP) still need to be addressed. Preliminary numerical studies of the prototype cavities have shown unacceptable damping for some higher-order dipole modes if the typical TESLA HOM couplers are directly adapted to the design. The resulting wakefield will dilute the beam emittance thus reduces the machine luminosity. Furthermore, high gradient tests on a 9-cell prototype at KEK have experienced MP barriers although a single LL cell had achieved a high gradient. From simulations, MP activities are found to occur in the end-groups of the cavity. In this paper, we will present the optimization results of the end-groups for the Low-Loss shape for effective HOM damping and alleviation of multipacting. Comparisons of simulation results with measurements will also be presented.

• L. Xiao
  
• C. Adolphsen, V. Akcelik, A. C. Kabel, K. Ko, L. Lee, Z. Li, C.-K. Ng
  SLAC, Menlo Park, California

The actual cell shape of the TESLA cavities differ from the ideal due to fabrication errors, the addition of stiffening rings and the frequency tuning process. Cavity imperfection shift the dipole mode frequencies and alter the Qext's from those computed for the idea cavity. A Qext increase could be problematic if its value exceeds the limit required for ILC beam stability. To study these effects, a cavity imperfection model was established using a mesh distortion method. The eigensolver Omega3P was then used to find the critical dimensions that contribute to the Qext spread and frequency shift by comparing predictions to TESLA cavity measurement data. Using the imperfection parameters obtained from these studies, artificial imperfection models were generated and the resulting wakefields were used as input to the beam tracking code Lucretia to study the effect on beam emittance. In this paper, we present the results of these studies and suggest tolerances for the cavity dimensions.

• L. Xiao
  
• L. Bellantoni
  Fermilab, Batavia, Illinois
• G. Burt
  Cockcroft Institute, Lancaster University, Lancaster
• P. Goudket, P. A. McIntosh
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• K. Ko, Z. Li, C.-K. Ng, G. L. Schussman, A. Seryi, R. Uplenchwar
  SLAC, Menlo Park, California

The FNAL 9-cell 3.9GHz deflecting cavity designed for the CKM experiment was chosen as the baseline design for the ILC BDS crab cavity. Effective damping is required for the lower-order TM01 modes (LOM), the same-order TM11 modes (SOM) as well as the HOM modes to minimize the beam loading and beam centroid steering due to wakefields. Simulation results of the original CKM design using the eigensolver Omega3P showed that both the notch filters of the HOM/LOM couplers are very sensitive to the notch gap, and the damping of the unwanted modes is suboptimal for the ILC. To meet the ILC requirements, the couplers were redesigned to improve the damping and tuning sensitivity. With the new design, the damping of the LOM/SOM/HOM modes is significantly improved, the sensitivity of the notch filter for the HOM coupler is reduced by one order of magnitude and appears mechanically feasible, and the LOM coupler is simplified by aligning it on the same plane as the SOM coupler and by eliminating the notch filter. In this paper, we will present the coupler optimization and tolerance studies for the crab cavity.

• H. Wang
  
• F. Marhauser
  JLAB, Newport News, Virginia
• R. A. Rimmer
  Jefferson Lab, Newport News, Virginia

After initial cavity shape optimization* and cryomodule development** for an Ampere-class FEL, we have simulated the whole 5-cell high-current (HC) cavity structure with six waveguide couplers for HOM damping and fundamental power coupling. The time-domain wakefield method using MAFIA is primarily used for calculation of the broadband impedance. Microwave Studio and Omega-3P are also used for the calculation of external Q (Qext) of individual HOMs. A half scale (1497MHz) single-cell model and a 5-cell copper cavity including dummy HOM waveguide loads were fabricated. Details of measurement results on these prototypes including HOM Qext spectrum, bead-pull data, data analysis technique and comparison to the simulations will be presented.

* H. Wang et. al., "Elliptical Cavity Shape Optimization for Acceleration and HOM Damping," Proc. PAC 05, Knoxville TN, USA, 2005* R. A.Rimmer et al.; EPAC 2006, paper MOPCH182

• D. Kramer
  

In 2006, GSI, together with a large international science community, presented the FAIR Baseline Technical Report (FBTR) on an unprecedented accelerator Facility for Antiproton and Ion beams Research in Europe, located in Darmstadt (Germany). This facility is based on extensive discussions and a broad range of workshops and working group reports, organized by the international user communities over a period of several years enabling unique experimental possibilities in the fields of nuclear- and astrophysics, hadron-, plasma and atomic physics as well as on applied physics. Following an in-depth evaluation of the proposal by the German Wissenschaftsrat and its recommendation to realize the facility, the Federal Government gave conditional approval for construction of FAIR in 2003. Since then the project has gone through major steps of development and significant progress has been achieved with regard to the scientific-technical and political preparation of the project under the governance of an international committee structure. The current status of the project will be reviewed.

• M. E. Schulze
  
• E. O. Abeyta, P. Aragon, R. Archuleta, J. Barraza, D. Dalmas, C. Ekdahl, K. Esquibel, S. Eversole, R. J. Gallegos, J. Harrison, E. Jacquez, J. Johnson, P. S. Marroquin, B. T. McCuistian, N. Montoya, S. Nath, L. J. Rowton, R. D. Scarpetti, M. Schauer
  LANL, Los Alamos, New Mexico
• R. Anaya, G. J. Caporaso, F. W. Chambers, Y.-J. Chen, S. Falabella, G. Guethlein, J. F. McCarrick, B. A. Raymond, R. A. Richardson, J. A. Watson, J. T. Weir
  LLNL, Livermore, California
• H. Bender, W. Broste, C. Carlson, D. Frayer, D. Johnson, A. Tipton, C.-Y. Tom
  NSTec, Los Alamos, New Mexico
• T. C. Genoni, T. P. Hughes, C. H. Thoma
  Voss Scientific, Albuquerque, New Mexico

• S. Molloy
  
• N. Baboi, O. Hensler, R. Paparella, L. M. Petrosyan
  DESY, Hamburg
• N. E. Eddy, L. Piccoli, R. Rechenmacher, M. Wendt
  Fermilab, Batavia, Illinois
• J. C. Frisch, J. May, D. J. McCormick, M. C. Ross, T. J. Smith
  SLAC, Menlo Park, California
• O. Napoly, C. Simon
  CEA, Gif-sur-Yvette

It is well known that an electron beam excites Higher Order Modes (HOMs) as it passes through an accelerating cavity~[panofsky68]. The properties of the excited signal depend not only on the cavity geometry, but on the charge and trajectory of the beam. It is, therefore, possible to use these signals as a monitor of the beam's position. Electronics were installed on all forty cavities present in the FLASH~[flashref] linac in DESY. These electronics filter out a mode known to have a strong dependence on the beam's position, and mix this down to a frequency suitable for digitisation. An analysis technique based on Singular Value Decomposition (SVD) was developed to calculate the beam's trajectory from the output of the electronics. The entire system has been integrated into the FLASH control system.

• C. Piel
  
• K. Dunkel, C. Schulz
  ACCEL, Bergisch Gladbach

• A. Ferrari
  

Strong beam-beam effects at the interaction point of a high-energy e⁺e^- linear collider such as CLIC lead to an emittance growth for the outgoing beams, as well as to the production of beamstrahlung photons and e⁺e^- coherent pairs. We present a conceptual design of the post-collision line for CLIC at 3 TeV, which separates the various components of the outgoing beam in a vertical magnetic chicane and then transports them to their respective dump.

• S. P. Antipov
  
• M. E. Conde, W. Gai, R. Konecny, W. Liu, J. G. Power, Z. M. Yusof
  ANL, Argonne, Illinois
• L. K. Spentzouris
  Illinois Institute of Technology, Chicago, Illinois

Metamaterials (MTM) are artificial periodic structures made of small elements and designed to obtain specific electromagnetic properties. As long as the periodicity and the size of the elements are much smaller than the wavelength of interest, an artificial structure can be described by a permittivity and permeability, just like natural materials. Metamaterials can be customized to have the permittivity and permeability desired for a particular application. Waveguides loaded with metamaterials are of interest because the metamaterials can change the dispersion relation of the waveguide significantly. Slow backward waves, for example, can be produced in a LHM-loaded waveguide without corrugations. In this paper we present theoretical studies and computer modeling of waveguides loaded with 2D anisotropic metamaterials, including the dispersion relation for a MTM-loaded waveguide. The dispersion relation of a MTM-loaded waveguide has several interesting frequency bands which are described. It is shown theoretically that dipole mode suppression may be possible. Therefore, metamaterials can be used to suppress wakefields in accelerating structures.

• D. J. Newsham
  
• S. A. Bogacz, Y.-C. Chao, Y. S. Derbenev
  Jefferson Lab, Newport News, Virginia
• R. P. Johnson, R. Sah
  Muons, Inc, Batavia

Parametric-resonance ionization cooling (PIC) is a muon-cooling technique that is useful for low-emittance muon colliders. This method requires a well-tuned focusing channel that is free of chromatic and spherical aberrations. In order to be of practical use in a muon collider, it also necessary that the focusing channel be as short as possible to minimize muon loss due to decay. G4Beamline numerical simulations are presented of a compact PIC focusing channel in which spherical aberrations are minimized by using design symmetry.

• K. Yonehara
  
• R. J. Abrams, M. A.C. Cummings, R. P. Johnson, S. A. Kahn, T. J. Roberts
  Muons, Inc, Batavia
• D. R. Broemmelsiek, M. Hu, A. Jansson, V. D. Shiltsev
  Fermilab, Batavia, Illinois

MANX is an experiment to prove that effective six-dimensional (6D) muon beam cooling can be achieved a Helical Cooling Channel (HCC) using ionization-cooling with helical and solenoidal magnets in a novel configuration. The aim is to demonstrate that 6D muon beam cooling is understood well enough to plan intense neutrino factories and high-luminosity muon colliders. The experiment consists of the HCC magnets that envelop a liquid helium energy absorber, upstream and downstream instrumentation to measure the particle or beam parameters before and after cooling, and emittance matching sections between the detectors and the HCC. We describe and compare the experimental configuration for both single particle and beam profile measurement techniques based on G4Beamline simulations.

• M. Venturini
  
• M. A. Furman, J.-L. Vay
  LBNL, Berkeley, California
• M. T.F. Pivi
  SLAC, Menlo Park, California

Electron cloud build-up and related beam instabilities are a serious concern for the positron damping ring of the International Linear Collider (ILC). To mitigate the effect use of grooved vacuum-chamber walls is being actively investigated in addition to more conventional techniques like surface coating, scrubbing, and/or conditioning. Experimental and simulation studies have characterized the effectiveness of the grooved surface by means of an effective secondary emission yield (SEY), which has been measured to be significantly lower than the SEY of a smooth surface of the same material. However, some inconsistencies of the results, and the need to model the experimental testing of the grooved surface concept in more detail, have motivated us to simulate the grooved surfaces directly. Specifically, we have augmented the code POSINST by adding the option to simulate the electron-cloud build-up in the presence of a grooved surface geometry. By computing the accumulated e-cloud density and comparing it with the same quantity computed for a smooth surface, we infer an effective SEY, and we thereby make contact with the effective SEY estimates obtained from previous studies.

• D. B. Cline
  
• Y. Fukui
  SLAC, Menlo Park, California
• A. A. Garren
  LBNL, Berkeley, California

• A. M. Cook
  
• H. Badakov, R. J. England, J. B. Rosenzweig, R. Tikhoplav, G. Travish, O. Williams
  UCLA, Los Angeles, California
• A. Kanareykin
  Euclid TechLabs, LLC, Solon, Ohio
• M. C. Thompson
  LLNL, Livermore, California

Experimental work is planned to study the performance of a beam-driven cylindrical dielectric wakefield accelerating structure as a source of THz coherent Cerenkov radiation. For an appropriate choice of dielectric tube geometry and driving electron bunch parameters, the device operates in a single-mode regime, producing narrow-band radiation in the THz range. This source can potentially produce high power levels relative to currently available sources, with ~50 μJ radiated energy per pulse achievable using the electron beam currently in operation at the Neptune Advanced Accelerator Research Laboratory at UCLA (~13 MeV beam energy, ~200 μm RMS bunch length, ~500 pC bunch charge). Preparations underway for installation of the experiment are discussed.

• R. Arnold
  
• V. N. Duginov, S. A. Kostromin, N. A. Morozov
  JINR, Dubna, Moscow Region
• A. Fisher, C. Hast, Z. Szalata, M. Woods
  SLAC, Menlo Park, California
• H. J. Schreiber, M. Viti
  DESY Zeuthen, Zeuthen

• S. Molloy
  
• C. Adolphsen, K. L.F. Bane, J. C. Frisch, Z. Li, J. May, D. J. McCormick, T. J. Smith
  SLAC, Menlo Park, California
• N. Baboi
  DESY, Hamburg
• N. E. Eddy, L. Piccoli, R. Rechenmacher
  Fermilab, Batavia, Illinois
• R. M. Jones
  UMAN, Manchester

Higher Order Modes (HOMs) excited by the passage of the beam through an accelerating cavity depend on the properties of both the cavity and the beam. It is possible, therefore, to draw conclusions on the inner geometry of the cavities based on observations of the properties of the HOM spectrum. A data acquisition system based on two 20 GS/s, 6 GHz scopes has been set up at the FLASH facility, DESY, in order to measure a significant fraction of the HOM spectrum predicted to be generated by the TESLA cavities used for the acceleration of its beam. The HOMs from a particular cavity at FLASH were measured under a range of known beam conditions. The dipole modes have been identified in the data. 3D simulations of different manufacturing errors have been made, and it has been shown that these simulations can predict the measured modes.

• S. Seletskiy
  

[1] 'International Linear Collider Reference Design Report', April 2007
[2] Y Nosochkov, A. Seryi, Phys. Rev. ST Accel. Beams 8, 021001 (2005)
[3] B. Parker, A. Seryi, Phys. Rev. ST Accel. Beams 8, 041001 (2005)

• P. Schoessow
  
• S. P. Antipov, M. E. Conde, W. Gai, J. G. Power
  ANL, Argonne, Illinois
• E. Bagryanskaya
  International Tomography Center, SB RAS, Novosibirsk
• V. Gorelik, A. Kovshik, A. V. Tyukhtin, N. Yevlampieva
  Saint-Petersburg State University, Saint-Petersburg
• A. Kanareykin
  Euclid TechLabs, LLC, Solon, Ohio
• L. Schachter
  Technion, Haifa

The PASER is a new method for particle acceleration, in which energy from an active medium is transferred to a charged particle beam. The effect is similar to the action of a maser or laser with the stimulated emission of radiation being produced by the virtual photons in the electromagnetic field of the beam. We are developing a demonstration PASER device operating at X-band, based on the availability of a new class of active materials that exhibit photoinduced electron spin polarization. We will report on the status of active material development and measurements, numerical simulations, and preparations for microwave PASER experiments at the Argonne Wakefield Accelerator facility.

• D. J. Summers
  
• L. M. Cremaldi, R. Godang, B. R. Kipapa, H. E. Rice
  UMiss, University, Mississippi
• R. B. Palmer
  BNL, Upton, Long Island, New York

Muon acceleration from 30 to 750 GeV in 72 orbits using two rings in the 1000m radius Tevatron tunnel is explored. The first ring ramps at 400 Hz and accelerates muons from 30 to 400 GeV in 28 orbits using 14 GV of 1.3 GHz superconducting RF. The ring duplicates the Fermilab 400 GeV main ring FODO lattice, which had a 61m cell length. Muon survival is 80%. The second ring accelerates muons from 400 to 750 GeV in 44 orbits using 8 GV of 1.3 GHz superconducting RF. The 30 T/m main ring quadrupoles are lengthened 87% to 3.3m. The four main ring dipoles in each half cell are replaced by three dipoles which ramp at 550 Hz from -1.8T to +1.8T interleaved with two 8T fixed superconducting dipoles. The ramping and superconducting dipoles oppose each other at 400 GeV and act in unison at 750 GeV. Muon survival is 92%. Two mm copper wire, 0.28mm grain oriented silicon steel laminations, and a low duty cycle mitigate eddy current losses. Low emittance muon bunches allow small aperatures and permit magnets to ramp with a few thousand volts. Little civil construction is required. The tunnel exists.

• B. Parker
  
• M. Anerella, J. Escallier, P. He, A. K. Jain, A. Marone
  BNL, Upton, Long Island, New York
• Y. Nosochkov, A. Seryi
  SLAC, Menlo Park, California

A wide variety of superconducting magnets are needed in the ILC Beam Delivery System (BDS) to maximize luminosity and minimize experimental backgrounds. Compact final focus quadrupoles and multifunction correction coils are used with 14 mr total crossing angle to focus incoming beams to few nanometer spot sizes while focusing outgoing disrupted beams into a separate extraction beam line. Large aperture anti-solenoids correct deleterious nonlinear effects that arise due to the overlap of focusing fields with the main detector solenoid. Far from the interaction point (IP) sets of strong small aperture octupoles help minimize backgrounds at the IP due to beam halo particles while weak large aperture dipoles integrated with the experimental detector reduce backgrounds due to beamstrahlung pairs generated at the IP. The physics requirements and magnetic design solutions for these magnets are reviewed in this paper.

• D. Trbojevic
  
• R. C. Gupta, B. Parker
  BNL, Upton, Long Island, New York
• E. Keil
  CERN, Geneva
• A. Sessler
  LBNL, Berkeley, California

We report on improvements in the non-scaling Fixed Field Alternating Gradient (FFAG) gantry design. As we previously reported*, a major challenge of the carbon/proton cancer therapy facilities is isocentric gantry design. The weight of the isocentric gantry transport elements in the latest Heidelberg carbon/proton facility is 135 tons**. In this report we detail improvements to the previous non-scaling gantry design. We estimate that this non-scaling FFAG gantry would be almost hundred times lighter than traditional heavy ion gantries. Very strong focusing with small dispersion permits passage of different energies of carbon beams through the gantry's fixed magnetic field.*

• F. W. Jones
  
• E. Y. Wildner
  CERN, Geneva

• W. Ackermann
  
• J. Enders, C. Heßler, Y. Poltoratska
  TU Darmstadt, Darmstadt
• W. F.O. Muller, B. Steiner, T. Weiland
  TEMF, Darmstadt

Beam dynamics simulations for computationally large problems are challenging tasks. On the one hand, to accurately simulate the electromagnetic field distribution within the whole device and the surrounding environment it is essential to consider all necessary device components including even small geometry details, complicated material distributions and the field excitations. On the other hand, further computational effort has to be put into precise modeling of the injected particle beam for detailed beam dynamics simulations. Under linear conditions, it is possible to separate the field calculation of the device from the computation of the particles self-field which can result in the proper application of diverse numerical schemes for the individual field contributions. In the paper it is demonstrated how the static electric and magnetic fields of a Wien filter beam line element can be treated as applied external fields within the beam dynamics simulation tool V-Code under the assumption that the interaction of the particle beam with the surrounding materials can be neglected.

• T. Kanesue
  
• M. Okamura, D. Raparia, J. Ritter
  BNL, Upton, Long Island, New York
• J. Tamura
  Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo

• Y. H. Chin
  
• Y. Shobuda
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• K. Takata
  KEK, Ibaraki

• Y. Shobuda
  
• Y. H. Chin, K. Takata
  KEK, Ibaraki

• G. M. Wang, G. M. Wang
  JLAB, Newport News, Virginia
• Y.-C. Chao, P. Evtushenko, G. Neil
  Jefferson Lab, Newport News, Virginia
• J.-E. Chen, C. Liu, X. Y. Lu, K. Zhao
  PKU/IHIP, Beijing

We present work directed at examining the performance of various front end components of an ERL based light source. These include electron source, bunch compression, merger, and accelerating sections, with parameter space dictated by proposed facilities (at FSU and Beijing University). These facilities share enough common structural features to make the study applicable to both to a large extent. In this report we will discuss the 6D phase space evolution through the front end based on simulation, with reliable modeling of magnetic and superconducting RF fields. Discussion will be devoted to relative merits of alternative designs, robustness and operational scenarios.

• K. Y. Kim
  
• Y.-S. Cho, B. Chung, J.-H. Jang
  KAERI, Daejon

The proton engineering frontier project (PEFP) 100-MeV proton linac has two main beamline systems to extract and deliver the proton beam to the user. The one is designed to extract 20-MeV proton beams at the medium energy transport system of the linac and to deliver them to five target stations through a beam switching system. The other is able to extract 100-MeV proton beams at the end of the linac and to deliver them to another five target stations trough a beam distribution system. We have completed the detailed beam optics designs of the beamline system and performed intensive error analyses to set the marginal limits of engineering errors of the beamline components by using a dedicated beam transport code. The paper presents the error analysis results of the PEFP beamline systems along with their characteristics and beam optics designs.

• S. A. Kostromin
  

• W. Bruns
  
• D. Schulte, F. Zimmermann
  CERN, Geneva

The electrostatic Particle in Cell code 'Faktor2' is extended to 3D, and is parallelised. Results for electron cloud buildup in end regions of damping ring dipoles for next generation linear colliders are presented.

• A. Latina
  
• R. J. Barlow, A. Bungau
  UMAN, Manchester
• G. A. Blair
  Royal Holloway, University of London, Surrey
• G. Rumolo, D. Schulte
  CERN, Geneva
• J. D.A. Smith
  Lancaster University, Lancaster

• E. Todesco
  
• R. W. Assmann, J.-P. Koutchouk, E. Metral, G. Sterbini, F. Zimmermann, R. de Maria
  CERN, Geneva

• L. L. Bandura
  
• B. Erdelyi
  Northern Illinois University, DeKalb, Illinois
• J. A. Nolen
  ANL, Argonne, Illinois

An exotic beam facility for the production of rare isotopes requires investigation of higher order optical effects, while taking into account beam-material interactions. An important component of the fragment separator is the absorber wedge, which is necessary for isotope separation. The properties of the absorber, such as the type and shape of material used, determine the resolution and transmission of the fragment separator. Nuclear reactions such as the fission and fragmentation of radioactive isotopes within the target or absorber contribute to the phase space and isotopic distributions of the beam. We have computed these distributions for all isotopes emerging from the target or absorber by implementing a limited fission model from within COSY Infinity that uses polynomial interpolations. Higher order optical aberrations have been computed and successfully eliminated by the shaping of the absorber material. COSY allows us to find the parameters of the absorber that maximize the resolution and transmission of the fragment separator. In addition, beam purity tests have been performed. From our results we have determined an appropriate location for a dump of the primary beam.

• Y.-E. S. Sun
  
• K.-J. Kim, J. G. Power
  ANL, Argonne, Illinois
• P. Piot, M. M. Rihaoui
  Northern Illinois University, DeKalb, Illinois

Transverse-to-longitudinal emittance exchange can be achieved through certain arrangements of dipole magnets and dipole mode rf cavity. Theory on such schemes has been developed in the past several years. In this paper we report our numerical simulations on the emittance exchange using particle tracking codes. Photoelectron beams with energy less than 20 MeV are used, as our purpose of simulations is to study the feasibility of performing such emittance exchange at existing facilities of beam energy at this level. Parametric studies of the dipole magnets and cavity strengths, as well as initial beam parameters, are presented.

• R. Miyamoto
  
• A. Jansson, M. J. Syphers
  Fermilab, Batavia, Illinois
• S. E. Kopp
  The University of Texas at Austin, Austin, Texas

• M. J. Syphers
  
• R. Miyamoto
  The University of Texas at Austin, Austin, Texas

Until recently, values of the amplitude functions through the Interaction Regions of the Tevatron collider detectors have been inferred either by reconstructing event locations through the detector and mapping out the luminous region to deduce the beam emittance and amplitude function or by performing differential closed orbit measurements while varying steering magnets and producing detailed models of the synchrotron's optical properties which reproduce the observed orbital deviations. Both of these methods rely on often lengthy off-line analyses and sometimes many hours of experimental data to obtain a meaningful result. The new Tevatron Beam Position Monitor system, commissioned in 2005, has allowed unprecedented detail of turn-by-turn motion to be measured at the 20-micron level and for thousands of beam revolutions. Such measurements performed with a freely oscillating proton beam, excited by a kicker magnet, allow for the direct measurement of the amplitude function which is model independent. A simple measurement procedure, data analysis method, and typical results for the Tevatron experimental regions are presented.

• S. Bernal
  
• B. L. Beaudoin, R. A. Kishek, P. G. O'Shea, M. Reiser, D. F. Sutter
  UMD, College Park, Maryland

The University of Maryland Electron Ring (UMER) is designed for the transport of low energy (10 keV), high current (100 mA) electrons in a 72-magnetic-quadrupole lattice over an 11.5 m circumference. With these parameters, and a typical single-particle phase advance per period of 76 deg., space charge is extreme. However, high current is not necessary for establishing space charge dominated transport in UMER. In fact, low current (0.6 mA) beam transport in combination with longer full-lattice periods can yield strong space charge conditions. All 72 quadrupoles are needed, though, to yield beams with relatively small cross sections, as required for emittance-dominated transport. We present results of calculations and experiments that demonstrate the low-current, high space charge regime in UMER. We also discuss the use of Collins-type insertions for matching into the ring lattice.

• L. Wang
  

Grooved surface is proposed to reduce the secondary emission yield in a dipole and wiggler magnet of International Linear Collider. An analysis of the impedance of the grooved surface based on adaptive finite element is presented in this paper. The performance of the adaptive algorithms, based on an element-element h-refinement technique, is assessed. The features of the refinement indictors, adaptation criteria and error estimation parameters are discussed.

• R. Li
  

In this study, we analyze the longitudinal effective CSR force for an energy-chirped Gaussian bunch moving relativistically on a circular orbit. With the geometry of the bunch tilt in dispersive regions (as induced by the initial energy-chirp) included in the retardation relation, the longitudinal effective CSR force thus calculated displays a variety of behaviors depending on the level of bunch compression. The variety ranges from the suppression of the longitudinal CSR force, for an undercompressed thin bunch, to an enhancement of the CSR interaction above that for a projected bunch, in a duration of path length shortly after the bunch crosses over the full compression point. The amplitude and duration of the enhancement depends on the bunch and lattice parameters. During this enhancement, the longitudinal effective CSR force depends sensitively on the particle's transverse position in the bunch. The physical picture of this phenomenon will be discussed.

• J. A. Holmes
  
• M. R. Perkett
  Denison University, Granville, Ohio
• M. A. Plum, J.-G. Wang, Y. Zhang
  ORNL, Oak Ridge, Tennessee

Simulations of the transport of H⁰ and H^- beams to the SNS ring injection dump are carried out using the ORBIT code. During commissioning and early operations, beam losses in this region have been the highest in the accelerator and presented the most obvious hurdle to cross in achieving high intensity operation. Two tracking models are employed:

1. a piecewise continuous symplectic representation of the lattice elements in the injection chicane and dump line, and
2. particle tracking in full 3D magnetic fields, as obtained from OPERA code evaluations.

• J.-G. Wang
  

The SNS ring injection dump beam line has been suffering high beam losses since its commissioning. In order to understand the mechanisms of the beam losses, we have built a 3D simulation model consisting of three injection chicane dipoles and one injection dump septum. The magnetic field distributions and the 3D particle trajectories in the model are obtained. The study has clearly shown two design problems causing beam losses in the injection dump beam line. This paper reports our simulation model, particle trajectory calculations, beam losses due to small vertical aperture of the injection dump septum and inadequate focusing down stream. The remedy of the beam losses is also discussed.

• M. Blaskiewicz
  

A multipurpose coherent instability simulation code has been written, documented, and released for use. TRANFT (tran-eff-tee) uses fast Fourier transforms to model transverse wakefields, transverse detuning wakes and longitudinal wakefields in a computationally efficient way. Dual harmonic RF allows for the study of enhanced synchrotron frequency spread. When coupled with chromaticity, the theoretically challenging but highly practical post head-tail regime is open to study. Detuning wakes allow for transverse space charge forces in low energy hadron beams, and a switch allowing for radiation damping makes the code useful for electrons.

• R. P. Fliller
  
• D. A. Edwards, H. Edwards
  Fermilab, Batavia, Illinois
• K. C. Harkay, K.-J. Kim
  ANL, Argonne, Illinois
• T. W. Koeth
  Rutgers University, The State University of New Jersey, Piscataway, New Jersey

The A0 photoinjector is being reconfigured to test the principal of transverse to longitudinal emittance exchange as proposed by Emma et. al., Kim and Sessler, and others. The ability to perform such an exchange could have major advantages to FELs by reducing the transverse emittance. Several schemes to carry out the exchange are possible and will be reported separately. At the Fermilab A0 Photoinjector we are constructing a beamline to demonstrate this transverse to longitudinal emittance exchange. This beamline will consist of a dogleg, and a TM110 5 cell copper cavity followed by another dogleg. The beamline is designed to reuse the bunch compressor dipoles of the photoinjector, along with some existing diagnostics. Beamline layout and optics discussed along with inital data. Future possibilites of performing a similar experiment at the proposed NML facility at Fermilab are also discussed.

• H. Hahn
  
• L. R. Hammons, D. Naik
  BNL, Upton, Long Island, New York

An R&D facility for an Energy Recovery Linac (ERL) intended as part of the 'Electron-Cooling Xperiment' for RHIC is being constructed at this laboratory. The center piece of the project is the experimental 5-cell 703.75 MHz superconducting ECX cavity. Successful operation will depend on effective HOM suppression, and it is planned to achieve HOM damping exclusively with room temperature ferrite absorbers. A ferrite-lined pillbox model with dimensions reflecting the operational unit was assembled, and the cavity resonances and quality factors were determined from scattering coefficient measurements and were interpreted as surface impedance. Results from a 5-cell copper cavity with an attached ferrite absorber prototype are used for the prediction of the ECX cavity HOM damping. A rotational symmetric ferrite-lined pillbox was analyzed theoretically and compared with the simulation codesμWave Studio, GdfidL, and Superfish. Discrepancies of the resonance frequencies and Q-values were found, and steps to reach agreement are discussed.

• M. Conte
  
• A. U. Luccio, W. W. MacKay
  BNL, Upton, Long Island, New York
• M. Pusterla
  Univ. degli Studi di Padova, Padova

• J. C. Tompkins
  
• J. A. Clarke
  Cockcroft Institute, Warrington, Cheshire
• V. S. Kashikhin
  Fermilab, Batavia, Illinois
• M. A. Palmer
  CLASSE, Ithaca
• B. Parker
  BNL, Upton, Long Island, New York

• L. Bottura
  
• P. Bestmann, N. Catalan-Lasheras, S. D. Fartoukh, S. S. Gilardoni, M. Giovannozzi, J. B. Jeanneret, M. Karppinen, A. M. Lombardi, K. H. Mess, D. P. Missiaen, M. Modena, R. Ostojic, Y. Papaphilippou, P. Pugnat, S. Ramberger, S. Sanfilippo, W. Scandale, F. Schmidt, N. Siegel, A. P. Siemko, D. Tommasini, T. Tortschanoff, E. Y. Wildner
  CERN, Geneva

• V. Chohan
  
• N. Ali, P. Awale, S. Bahuguna, V. Chauhan, M. Y. Dixit, J. A. Gore, J. John, E. Kandaswamy, A. Kasbekar, P. Kashyap, C. P. Kulkarni, A. Laddha, S. Malhotra, M. Mascarenhas, J. K. Mishra, P. Motiwala, K. Nair, R. Narayanan, S. Padmakumar, A. Pagare, D. Peruppayikkad, S. Raghunathan, S. Rao, D. Roy, S. Sethumadhavan, S. Sharma, S. Shimjith, S. Singh, S. T. Sonnis, P. Surendran, A. Tikaria
  BARC, Mumbai
• U. Bhunia
  DAE/VECC, Calcutta
• G. H. Hemelsoet, F. Pirotte, K. Priestnall, E. Veyrunes
  CERN, Geneva
• A. Kasliwal
  RRCAT, Indore (M. P.)

• G. Moritz
  

• R. I. Saban
  
• R. Alemany-Fernandez, V. Baggiolini, A. Ballarino, E. Barbero-Soto, B. Bellesia, F. Bordry, D. Bozzini, M. P. Casas Lino, V. Chareyre, S. D. Claudet, G.-J. Coelingh, K. Dahlerup-Petersen, R. Denz, M. Gruwe, V. Kain, G. Kirby, M. Koratzinos, R. J. Lauckner, S. L.N. Le Naour, K. H. Mess, F. Millet, V. Montabonnet, D. Nisbet, B. Perea-Solano, M. Pojer, R. Principe, S. Redaelli, A. Rijllart, F. Rodriguez-Mateos, R. Schmidt, L. Serio, A. P. Siemko, M. Solfaroli Camillocci, H. Thiesen, W. Venturini Delsolaro, A. Vergara-Fernandez, A. P. Verweij, M. Zerlauth
  CERN, Geneva
• SF. Feher, R. H. Flora, R. Rabehl
  Fermilab, Batavia, Illinois

• A. Chance
  
• J. Payet
  CEA, Gif-sur-Yvette

The aim of the beta-beams is to produce highly energetic beams of pure electron neutrino and anti-neutrino, coming from beta-decays of the ¹⁸Ne¹⁰⁺ and ⁶He²⁺, both at γ=100, directed towards experimental halls situated in the Frejus tunnel. The high intensity ion beams are stored in a ring until the ions decay. The beta decay products have a magnetic rigidity different from the one of the parent ions and are differently deflected in the 6T superconducting dipoles. Consequently, all the injected ions are lost anywhere in the ring, generating a high level of irradiation. So, the dipole apertures need to be large enough to avoid the decay products hitting their walls, which may worsen the field quality. A study on its tolerances has been carried out. Since the decay ring has to accept the beam during a large number of turns, the chosen criteria is the size of the dynamic aperture that the multipolar defects in the dipoles may shrink. Tolerances on the systematic and random errors of these defects have been investigated. In order to relax the tolerances, a routine was written which enlarges automatically the dynamic aperture in presence of field errors.

• S. Khodyachykh
  
• D. Alesini, L. Ficcadenti
  INFN/LNF, Frascati (Roma)
• G. Asova, J. W. Baehr, C. H. Boulware, H.-J. Grabosch, M. Hanel, S. A. Korepanov, M. Krasilnikov, S. Lederer, A. Oppelt, B. Petrosyan, S. Rimjaem, J. Roensch, T. A. Scholz, L. Staykov, F. Stephan
  DESY Zeuthen, Zeuthen
• T. Garvey
  LAL, Orsay
• L. H. Hakobyan
  YerPhI, Yerevan
• D. J. Holder, B. D. Muratori
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• R. Richter
  BESSY GmbH, Berlin
• R. Spesyvtsev
  KhNU, Kharkov

The Photo-Injector Test Facility at DESY in Zeuthen (PITZ) is an electron accelerator which was built to develop and optimize high brightness electron sources suitable for SASE FEL operation. Currently, in parallel to the operation of the existing setup, a large extension of the facility and its research program is ongoing. The beam line which has a present length of about 13 meters will be extended up to about 21 meters within the next two years. Many additional diagnostics components will be added to the present layout. Two high-energy dispersive arms, an RF deflecting cavity and a phase space tomography module will extend the existing diagnostic system of the photo injector and will contribute to the full characterization of new electron sources. We will report on the latest developments of the beam diagnostics at PITZ.

• L. Ficcadenti
  
• D. Alesini, G. Di Pirro, C. Vaccarezza
  INFN/LNF, Frascati (Roma)
• A. Mostacci, L. Palumbo
  Rome University La Sapienza, Roma
• J. B. Rosenzweig
  UCLA, Los Angeles, California

This work has been partially supported by the EU in the sixth framework program, Contract no. 011935 EUROFEL-DS1.

• M. Sawamura
  

• S. H. Shin
  
• Y. Honda, J. Urakawa
  KEK, Ibaraki
• E.-S. Kim, H.-S. Kim
  Kyungpook National University, Daegu

• H. Damerau
  
• S. Hancock, C. Rossi, E. N. Shaposhnikova, J. Tuckmantel, J.-L. Vallet
  CERN, Geneva
• M. Mehler
  GSI, Darmstadt

Longitudinal coupled bunch instabilities in the CERN PS represent a major limitation to the high brightness beam delivered for the LHC. To identify possible impedance sources for these instabilities, machine development studies have been carried out. The growth rates of coupled bunch modes have been measured, and modes have been identified using mountain range data. Growth rate estimations from coupled bunch mode theory are compared to these results. It is shown that the longitudinal impedance of the broad resonance curve of the main 10 MHz RF system can be identified as the most probable source. Possible methods to improve the beam stability are analyzed together with the performance of a damping system.

• A. Lyapin
  
• C. Adolphsen, R. Arnold, C. Hast, D. J. McCormick, Z. Szalata, M. Woods
  SLAC, Menlo Park, California
• S. T. Boogert, G. E. Boorman
  Royal Holloway, University of London, Surrey
• M. V. Chistiakova, Yu. G. Kolomensky, E. Petigura, M. Sadre-Bazzaz
  UCB, Berkeley, California
• V. N. Duginov, S. A. Kostromin, N. A. Morozov
  JINR, Dubna, Moscow Region
• F. Gournaris, B. Maiheu, D. J. Miller, M. Wing
  UCL, London
• M. Hildreth
  Notre Dame University, Notre Dame, Iowa
• H. J. Schreiber, M. Viti
  DESY Zeuthen, Zeuthen
• M. Slater, M. Thomson, D. R. Ward
  University of Cambridge, Cambridge

• R. M. Jones
  
• C. J. Glasman
  UMAN, Manchester

• L. Emery
  

The short-pulse X-ray project at the Advanced Photon Source (APS) uses three room-temperature nine-cell 2.815 GHz deflecting-mode cavities in a straight section. Undamped, these cavities' higher-order and lower-order resonator modes will cause multi-bunch instabilities in longitudinal and transverse planes for any bunch pattern of a 1'000mA store. Damping of these modes must be part of the design of the cavities. We report calculations of instability growth rates and tracking simulations that were essential in specifying the rf design of the damping structures. We used various operating bunch patterns and scanned levels of damping of the cavities. Because one of the operating bunch patterns is not symmetric, we used a normal mode analysis * implemented in the APS code clinchor. Our calculation included random sampling of resonator frequencies in a reasonable range. We found that staggering of frequencies is only effective for modes that could not be heavily damped.

* K. Thompson and R. Ruth, PAC 1989

• R. M. Lill
  
• L. H. Morrison, W. E. Norum, N. Sereno, G. J. Waldschmidt, D. R. Walters
  ANL, Argonne, Illinois
• S. Smith, T. Straumann
  SLAC, Menlo Park, California

In this paper we present the design of the beam position monitor (BPM) system for the LCLS undulator, which features a high resolution X-band cavity BPM. Each BPM has a TM010 monopole reference cavity and a TM110 dipole cavity designed to operate at a center frequency of 11.384 GHz. The signal processing electronics features a low-noise single-stage three-channel heterodyne receiver that has selectable gain and a phase locking local oscillator. We will discuss the system specifications, design, and prototype test results.

• R. Miyamoto
  
• A. Jansson, M. J. Syphers
  Fermilab, Batavia, Illinois
• S. E. Kopp
  The University of Texas at Austin, Austin, Texas

• M. M. Rihaoui
  
• C. L. Bohn, P. Piot
  Northern Illinois University, DeKalb, Illinois
• J. G. Power
  ANL, Argonne, Illinois

• B. Blind
  
• J. D. Gilpatrick
  LANL, Los Alamos, New Mexico

In order to characterize the beam-centroid jitter in transverse phase space, sets of position data of the 100-MeV H⁺ beam and 800-MeV H^- beam were taken in the transport lines of the Los Alamos Neutron Science Center (LANSCE) accelerator complex. Subsequent data evaluation produced initially puzzling inconsistencies in the phase-space plots from different pairs of beam-position monitors. It is shown that very small random measurement errors will produce systematic differences between plots that should nominally be identical. The actual beam-centroid jitter and the amount of random error in the measurements can be extracted from the data by performing simulations and determining the parameters for which the resulting plots are consistent with the results from the data. Examples will be shown.

• R. M. Jones
  
• G. Burt
  Cockcroft Institute, Lancaster University, Lancaster
• N. Chanlek, B. Spencer
  UMAN, Manchester
• P. Goudket
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

• H. Loos
  
• T. Borden, P. Emma, J. C. Frisch, J. Wu
  SLAC, Menlo Park, California

The ultra-short bunches of the electron beam for LCLS are generated in two 4-dipole bunch compressors located at energies of 250 MeV and 4.3 GeV. Although an absolute measurement of the bunch length can be done by using a transverse deflecting cavity in an interceptive mode, a non-interceptive single shot method is needed as a relative measurement of the bunch length used in the continuous feedback for beam energy and peak current. We report on the design and implementation of two monitors measuring the integrated power of coherent edge radiation from the last dipole in each chicane. The first monitor is installed in early 2007 and we compare its performance with the transverse cavity measurement and other techniques.

• A. Novokhatski
  
• S. DeBarger, S. Ecklund, N. Kurita, J. Seeman, M. K. Sullivan, S. P. Weathersby, U. Wienands
  SLAC, Menlo Park, California

A new Q2-bellows absorber will damp only transverse wake fields and will not produce additional beam losses due to Cherenkov radiation. The design is based on the results of the HOM analysis. Geometry of the slots and absorbing tiles was optimized to get maximum absorbing effect.

• L. Wang
  
• K. L.F. Bane, C. Chen, T. M. Himel, M. Munro, M. T.F. Pivi, T. O. Raubenheimer, G. V. Stupakov
  SLAC, Menlo Park, California

The development of an electron cloud in the vacuum chambers of high intensity positron and proton storage rings may limit machine performance. The suppression of electrons in a magnet is a challenge for the positron damping ring of the International Linear Collider (ILC) as well as the Large Hadron Collider. Simulation show that grooved surfaces can significantly reduce the electron yield in a magnet. Some of the secondary electrons emitted from the grooved surface return to the surface within a few gyrations, resulting in a low effective secondary electron yield (SEY) of below 1.0 A triangular surface is an effective, technologically attractive mitigation with a low SEY and a weak dependence on the scale of the corrugations and the external magnetic field. A chamber with triangular grooved surface is proposed for the dipole and wiggler sections of the ILC and will be tested in PEP-II in 2007. The strategy of electron cloud control in ILC and the optimization of the grooved chamber such as the SEY, impedance as well as the manufacturing of the chamber, are also discussed.

SLAC-PUB-11933 & NIMA in publication

• L. Wang
  
• Z. Li, A. Seryi
  SLAC, Menlo Park, California

The effects of the round edge beam hole on the frequency and wake field are studied using variational method, which allows for rounded iris disk hole without any approximation in shape treatment. The frequency and wake field of accelerating mode and dipole mode are studied for different edge radius cases, including the flat edge shape that is often used to approximately represent the actual structure geometry. The edge hole shape has weak effect on the frequency, but much effect on the wake field. Our study shows that the amounts of wake fields are not precise enough with the assumption of the flat edge beam hole instead of round edge.

• J. Wu
  
• A. Chao
  SLAC, Menlo Park, California
• J. R. Delayen
  Jefferson Lab, Newport News, Virginia

For accelerator projects with ultra short electron beam, beam dynamics study has to invoke the short-range wakefield. In this paper, we first obtain the short-range dipole mode resistive wall wakefield. Analytical approach is then developed to study the single bunch transverse beam dynamics due to this short-range resistive wall wake. The results are applied to the LCLS undulator and some other proposed accelerators.

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

The existence of multipolar components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. So, a realistic non-linear model is crucial for understanding the beam behavior and to achieve the ultimate performance in RHIC. A procedure is developed to build a non-linear model using the available multipolar component data obtained from measurements of RHIC magnets. We first discuss the measurements performed at different stages of manufacturing of the magnets in relation to their current state in RHIC. We then describe the procedure to implement these measurement data into tracking models, including the implementation of the multipole feed down effect due to the beam orbit offset from the magnet center. Finally, the field quality analysis in the RHIC interaction regions is presented.

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

• Y. Luo
  
• M. Bai, J. Bengtsson, R. Calaga, W. Fischer, N. Malitsky, F. C. Pilat, T. Satogata
  BNL, Upton, Long Island, New York

To further improve the polarized proton (pp) run collision luminosity in the Relativistic Heavy Ion Collider, correction of the horizontal two-third resonance is desirable to increase the available tune space. The third resonance driving term (RTD) is measured with the turn-by-turn (TBT) beam position monitor (BPM) data with AC dipole excitation. A first order RTD response matrix based on the optics model is used to on-line compensate the third resonance driving term h30000 while keeping other first order RTDs and first order chromaticities unchanged. The results of beam experiment and simulation correction are presented and discussed.

• Y. Luo
  
• W. Fischer, N. Malitsky, S. Tepikian, D. Trbojevic
  BNL, Upton, Long Island, New York

With 8 arc sextupole families in each RHIC ring, the nonlinear chromaticities can be corrected on-line by matching the off-momentum tunes onto the wanted off-momentum tunes with linear chromaticity only. The Newton method with singular value decomposition (SVD) technique is used for this multi-dimensional nonlinear optimization, where the off-momentum tune response matrix with respect to sextupole strength changes is adopted to simplify and fasten the on-line optimization process. The off-momentum tune response matrix can be calculated with the on-line accelerator optics model or directly measured with the real beam. This correction method will be verified and used in the coming RHIC run'07.

• Y. Luo
  
• M. Bai, J. Beebe-Wang, W. Fischer, A. K. Jain, C. Montag, T. Roser, S. Tepikian, D. Trbojevic
  BNL, Upton, Long Island, New York

To further improve the the polarized proton (pp) luminosity in the Relativistic Heavy Ion Collider, the beta functions at the two interaction points (IPs) will be reduced from 1.0 m to 0.9m in 2007. In addition, it is planned to increase the bunch intensity from 1.5*10¹¹ to 2.0*10¹¹. To accommodate these changes, the nonlinear chromaticities and the third resonance driving term should be corrected. In 2007, the number of the arc sextupole power supplies will be doubled from 12 to 24, which allows nonlinear chromaticity correction. With the updated field errors in the interaction regions (IRs), detailed dynamic aperture studies are carried out to optimize the nonlinear correction schemes, and increase the available tune space in collision.