• J. Seeman
  
• Y. Cai, M. K. Sullivan, U. Wienands
  SLAC, Menlo Park, California

For the PEP-II Operation Staff: PEP-II is an asymmetric e⁺e^- collider operating at the Upsilon 4S and has recently set several performance records. The luminosity has reached 1.2x10³⁴/cm²/s and has delivered an integrated luminosity of 910/pb in one day. PEP-II operates in continuous injection mode for both beams boosting the integrated luminosity. The peak positron current has reached 3.0 A of positrons and 1.9 A of electrons in 1732 bunches. The total integrated luminosity since turn on in 1999 has reached over 410/fb. This paper reviews the present performance issues of PEP-II and also the planned increase of luminosity in the near future to over 2 x 10³⁴/cm²/s.

• 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

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

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

• A. Daly
  
• C. W. Appelbee, D. Bayley
  STFC/RAL/ISIS, Chilton, Didcot, Oxon

• N. Marks
  
• B. J.A. Shepherd
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

• 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.

• M. Benedikt
  
• W. Bartmann, C. Carli, B. Goddard, S. Hancock, J. M. Jowett, Y. Papaphilippou
  CERN, Geneva

• M. A. Furman
  
• C. M. Celata, M. Kireeff Covo, K. G. Sonnad, J.-L. Vay, M. Venturini
  LBNL, Berkeley, California
• R. H. Cohen, A. Friedman, D. P. Grote, A. W. Molvik
  LLNL, Livermore, California
• P. Stoltz
  Tech-X, Boulder, Colorado

We present recent advances in the modeling of beam-electron-cloud dynamics, including surface effects such as secondary electron emission, gas desorption, etc, and volumetric effects such as ionization of residual gas and charge-exchange reactions. Simulations for the HCX facility with the code WARP/POSINST will be described and their validity demonstrated by benchmarks against measurements. The code models a wide range of physical processes and uses a number of novel techniques, including a large-timestep electron mover that smoothly interpolates between direct orbit calculation and guiding-center drift equations, and a new computational technique, based on a Lorentz transformation to a moving frame, that allows the cost of a fully 3D simulation to be reduced to that of a quasi-static approximation.

• L. Yang
  
• X. Huang
  SLAC, Menlo Park, California
• S.-Y. Lee
  IUCF, Bloomington, Indiana
• B. Podobedov
  BNL, Upton, Long Island, New York

The Orbit Response Matrix (ORM) has been successfully used extensively in accelerator modeling. However, in many cases, the existing codes can not find a correct model. We develop a new code that solve the convergence and coupling problems. We test our code by carrying out systematic study of accelerator models. Effects measurement errors and the completeness of information will be addressed in this study. Possible inclusion of phase information will be discussed.

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

The Paul Trap Simulator Experiment is a compact laboratory Paul trap that simulates a long, thin charged-particle bunch coasting through a kilometers-long magnetic alternating-gradient (AG) transport system by putting the physicist in the beam's frame-of-reference. The transverse dynamics of particles in both systems are described by the same sets of equations, including all nonlinear space-charge effects. The time-dependent quadrupolar electric fields created by the confinement electrodes of a linear Paul trap correspond to the axially-dependent magnetic fields applied in the AG system. Results are presented from experiments in which the lattice period and strength are changed over the course of the experiment to transversely compress a beam with an initial depressed-tune of 0.9. Instantaneous and smooth changes are considered. Emphasis is placed on determining the conditions that minimize the emittance growth and the number of halo particles produced after the beam compression. The results of PIC simulations performed with the WARP code agree well with the experimental data. Initial results from a newly installed laser-induced fluorescence diagnostic will also be discussed.

• D. Xiang
  
• Y.-C. Du, W.-H. Huang, R. K. Li, Y. Lin, C.-X. Tang, L. X. Yan
  TUB, Beijing
• J. H. Park, S. J. Park
  PAL, Pohang, Kyungbuk

There are growing interests in generation, preservation and applications of high brightness electron beam. With the rapid development in the techniques for emittance compensation and laser shaping, we are approaching the limit-the uncorrelated thermal emittance. In this paper, we report the measurements of thermal emittance for Cu and Mg. The measurement is conducted in a field-free region. The energy spectrum and angular distribution of the electrons are measured immediately after its emission and further used to reconstruct the initial phase space and the corresponding thermal emittance. We also show how cathode surface roughness* and laser incidence angle as well as its polarization state** affect the quantum efficiency and thermal emittance.

*X. Z. He, High energy physics and nuclear physics,28(2004)1007.**Dao Xiang,et al, NIM A,562(2006)48.

• 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

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

• I. P.S. Martin
  
• R. Bartolini, R. T. Fielder, E. C. Longhi, B. Singh
  Diamond, Oxfordshire

• M. Borland
  
• L. Emery
  ANL, Argonne, Illinois

The Advanced Photon Source (APS) is a 7-GeV storage ring light source that has been in operation for over a decade. Over time, the performance of the APS has been increased by reduction of the emittance from 8 nm to 3.1 nm and by the use of top-up mode. We continue to explore options for improving the performance further. This paper discusses the possible improvements in emittance that could result from the use of damping wigglers. We also discuss rf and space requirements.

• 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.

• V. P. Suller
  
• M. G. Fedurin
  BNL, Upton, Long Island, New York
• P. Jines, D. J. Launey, T. A. Miller, Y. Wang
  LSU/CAMD, Baton Rouge, Louisiana

• H. Nishimura
  
• S. Marks, D. Robin, D. Schlueter, C. Steier, W. Wan
  LBNL, Berkeley, California

The possibility exists of achieving significantly lower emittances in an electron storage ring by increasing its horizontal betatron tune. However, existing magnet locations and strengths in a given ring may be inadequate to implement such an operational mode. For example, the ALS storage ring could lower its emittance to one third of the current value by increasing the horizontal tune from 14.25 to 16.25. However, this would come with the cost of large chromaticities that could not be corrected with our existing sextupole magnets. We discuss such operational issues and possible options in this paper.

• D. Robin
  
• W. Wan
  LBNL, Berkeley, California

The triple bend achromat cell of the ALS has been shown to be very flexible and compact. It has been operated in a low emittance mode and a low momentum compaction mode. In fact the lattice can be operated in a large range of different stable modes. Until recently most of these recently discovered modes had not been explored or even known about. Many of these modes have potentially attractive features as compared with the present operational mode. In this paper we take a step back and look at the general stability limits of the lattice. We employ a technique we call GLASS that allows us to rapidly scan and find all possible stable modes and then characterize their associated properties. In this paper we illustrate how the GLASS technique gives a global and comprehensive vision of the capabilities of the lattice.

• C. Song
  
• G. Hoffstaetter
  CLASSE, Ithaca

Multi-pass, multi-bunch beam-breakup (BBU) can limit the current in linac-based recirculating accelerators. We have therefore made the computation of the transverse and longitudinal BBU-threshold current available in Cornell's main optics design and beam simulation library BMAD. The coupling of horizontal and vertical motion as well as time of flight effects are automatically contained. Subsequently we present a detailed simulation study of transverse and longitudinal BBU in the proposed 5GeV Energy Recovery Linac light source at Cornell University, including the use of frequency randomization, polarized cavities and optical manipulations to improve the threshold current.

• X. Huang
  

* M. Borland, APS Report LS-287

• X. Huang
  
• W. J. Corbett, Y. Nosochkov, J. A. Safranek, J. J. Sebek, A. Terebilo
  SLAC, Menlo Park, California

• I. Pinayev
  
• J. Rose, T. V. Shaftan, L.-H. Yu
  BNL, Upton, Long Island, New York

• B. Podobedov
  
• L. Yang
  IUCF, Bloomington, Indiana

• T. V. Shaftan
  
• J. Beebe-Wang, J. Bengtsson, G. Ganetis, W. Guo, R. Heese, H.-C. Hseuh, E. D. Johnson, V. Litvinenko, A. U. Luccio, W. Meng, S. Ozaki, I. Pinayev, S. Pjerov, D. Raparia, J. Rose, S. Sharma, J. Skaritka, C. Stelmach, N. Tsoupas, D. Wang, L.-H. Yu
  BNL, Upton, Long Island, New York

We present conceptual design of the NSLS-II injection system. The injection system consists of low-energy linac, booster and transport lines. We review the requirements on the injection system imposed by the storage ring design and means of meeting these requirements. We discuss main parameters and layout of the injection system components.

• S. R. Koscielniak
  

Linear-field non-scaling FFAGs are proposed for multi-GeV muon acceleration and order hundred MeV/u proton or carbon medical applications. The periodic lattices, which have large momentum acceptance (factor >3), employ cells comprised of combined function magnets. In one implementation, rectangular-shaped quadrupoles are used, with the dipole component generated by off-setting the magnet centre. This feature, coupled with the large radial aperture, gives rise to orbits with large displacement and/or divergence from the quadrupole centre. The angles may be so large that there is a partial interchange of longitudinal and radial momenta. We examine two methods to devise maps (through the body field) that are third order in radial coordinate and higher order in momentum. The WKBJ approximation is concluded to be no better than the usual linear transfer matrix. A Green's function approach is carried through to non-linear mappings for the dynamical variables, which are coupled. The first partial derivative of this map (relates to tune variation) produces a linear transfer matrix which must have unity determinant. For the FFAG application, the map is comparable with numerical integration.

• T. Planche
  
• B. Autin, J. Fourrier, E. Froidefond, J. Pasternak
  LPSC, Grenoble
• J. L. Lancelot, D. Neuveglise
  Sigmaphi, Vannes
• F. Meot
  CEA, Gif-sur-Yvette

2-D and 3-D magnetic calculation tools and methods have been developed at SIGMAPHI, in collaboration with IN2P3/LPSC, to design spiral FFAG magnets. These tools are currently being used for RACCAM spiral scaling FFAG magnet design. In the particular case of a spiral gap shaped magnet, a careful magnetic design has to be realized in order to keep both vertical and horizontal tunes constant during acceleration process. Promising results, obtained from tracking in 3-D field maps, demonstrate the efficiency of the horizontal and vertical tune adjustment methods presented in this paper.

• J. Pasternak
  
• B. Autin
  CERN, Geneva
• J. Fourrier, E. Froidefond
  LPSC, Grenoble
• F. Meot
  CEA, Gif-sur-Yvette
• D. Neuveglise, T. Planche
  Sigmaphi, Vannes

• C. Omet
  
• D. Hoffmann, P. J. Spiller
  GSI, Darmstadt

Beam loss caused by charge changing process in connection with dynamic vacuum effects may limit the maximum number of accelerated heavy ions with low charge states in the existing synchrotron SIS18 and the planned SIS100/SIS300 of the FAIR project. With the aim to stabilize the vacuum dynamics and to control ionization beam loss, a substantial upgrade program has been defined for SIS18 and is presently realized. For SIS100, a new lattice design concept has been developed, where each lattice cell acts as a charge seperator and thereby enables the local control of beam loss. Simulation, conducted with the code STRAHLSIM, of the time dependent evolution of beam loss, dynamic residual gas pressure and the effect of the proposed dedicated ion catcher systems will be presented.

• 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

• Y. Ohnishi
  
• M. E. Biagini, P. Raimondi
  INFN/LNF, Frascati (Roma)
• Y. Cai, J. Seeman, M. K. Sullivan, U. Wienands
  SLAC, Menlo Park, California
• A. Wolski
  Liverpool University, Science Faculty, Liverpool

* P. Raimondi, "New Developments for SuperB Factories", Invited talk, this Conference

• B. Jones
  
• D. J. Adams, C. M. Warsop
  STFC/RAL/ISIS, Chilton, Didcot, Oxon

• P. N. Ostroumov
  
• B. Mustapha, J. A. Nolen
  ANL, Argonne, Illinois

The Advanced Exotic Beam Laboratory (AEBL) being developed at ANL consists of an 833 MV heavy-ion driver linac capable of producing uranium ions up to 200 MeV/u and protons to 580 MeV with 400 kW beam power. We have designed all accelerator components including a two charge state LEBT, an RFQ, a MEBT, a superconducting linac, a stripper section and beam switchyard. We present the results of an optimized linac design and end-to-end simulations which include possible machine errors.

• J.-P. Carneiro
  
• D. E. Johnson
  Fermilab, Batavia, Illinois

• W. Chou
  
• C. L. Bartelson, B. C. Brown, D. Capista, J. L. Crisp, J. DiMarco, J. Fitzgerald, H. D. Glass, D. J. Harding, B. Hendricks, D. E. Johnson, V. S. Kashikhin, I. Kourbanis, W. F. Robotham, T. Sager, M. Tartaglia, L. Valerio, R. C. Webber, M. Wendt, D. Wolff, M.-J. Yang
  Fermilab, Batavia, Illinois

A two-year Large Aperture Quadrupole (WQB) Project was completed in the summer of 2006 at Fermilab.* Nine WQBs were designed, fabricated and bench-tested by the Technical Division. Seven of them were installed in the Main Injector and the other two for spares. They perform well. The aperture increase meets the design goal and the perturbation to the lattice is minimal. The machine acceptance in the injection and extraction regions is increased from 40π to 60π mm-mrad. This paper gives a brief report of the operation and performance of these magnets. Details can be found in Ref**.

* D. Harding et al, "A Wide Aperture Quadrupole for the Fermilab Main Injector," this conference.
** W. Chou, Fermilab Beams-doc-#2479, http://beamdocs.fnal.gov/AD-public/DocDB/DocumentDatabase

• D. E. Johnson
  

• J. R. Lackey
  
• F. G. Garcia, M. Popovic, E. Prebys
  Fermilab, Batavia, Illinois

The operation and performance of the new, 15 Hz, H^- charge exchange injection system for the FNAL Booster is described. The new system installed in 2006 was necessary to allow injection into the Booster at up to 15 Hz. It was built using radiation hardened materials which will allow the Booster to reliably meet the high intensity and repetition rate requirements of the Fermilab's HEP program. The new design uses three orbit bump magnets (Orbmps) rather than the usual four and permits injection into the Booster without a septum magnet. Injection beam line modification and compensation for the quadrupole gradients of the Orbmp magnets is discussed.

• D. E. Johnson
  
• M. Xiao
  Fermilab, Batavia, Illinois

Upon the termination of the Fermilab Collider program, the current Recycler anti-proton storage ring will be converted to a proton pre-injector for the Main Injector synchrotron. This is scheduled to increase the beam power for the 120 GeV Neutrino program to upwards of 700KW. A transport line that can provide direct injection from the Booster to the Recycler while preserving direct injection from the Booster into the Main Injector and the 8 GeV Booster Neutrino program will be discussed,and its concept design will be presented.

• M. Xiao
  
• D. E. Johnson
  Fermilab, Batavia, Illinois

Upon the termination of the Fermilab Collider program, the current Recycler anti-proton storage ring will be converted to a proton pre-injector for the Main Injector synchrotron. This is scheduled to increase the beam power for the 120 GeV Neutrino program to upwards of 700KW. Due to momentum aperture restriction, a new transport line that extracts the beam from the Recycler at a dispersion free region to the main injector will be discussed, and its concept design will be presented.

• G. Yocky
  
• Y. Cai, F.-J. Decker, Y. Nosochkov, U. Wienands
  SLAC, Menlo Park, California
• P. Raimondi
  INFN/LNF, Frascati (Roma)

• A. G. Ruggiero
  
• J. G. Alessi, E. N. Beebe, A. I. Pikin, T. Roser, D. Trbojevic
  BNL, Upton, Long Island, New York

We explore the possibility of using two non-scaling FFAG with a smaller number of distributed RF cavities for a high power heavy ion driver. The pulsed heavy ion source would consist of an Electron Beam Ion Source (EBIS), fed continuously from a high charge state Electron Cyclotron Resonance (ECR) source. The Radio Frequency Quadrupole (RFQ) and a short 10 MeV/u linac would follow the ion source. Microseconds long heavy ion beam bunches from the EBIS would be injected in a single turn into a multi-pass small aperture non-scaling Fixed Field Alternating Gradient (FFAG) accelerator. The heavy ion maximum kinetic energy is assumed to be 400 MeV/u with a total of 400 kW power for uranium ion beams. Partially stripped heavy ions would be accelerated from 10 MeV/u to 67 MeV/u with a first non-scaling FFAG, while, after further stripping, a second non-scaling FFAG would accelerate from 67 to 400 MeV/u.

• X. Chang
  
• I. Ben-Zvi, A. Burrill, J. G. Grimes, T. Rao, Z. Segalov, J. Smedley
  BNL, Upton, Long Island, New York
• Q. Wu
  IUCF, Bloomington, Indiana

• C. W. Appelbee
  
• A. Daly
  STFC/RAL, Chilton, Didcot, Oxon
• A. Seville
  STFC/RAL/ISIS, Chilton, Didcot, Oxon

• L. Ristori
  
• G. Apollinari, I. G. Gonin, T. N. Khabiboulline, G. Romanov
  Fermilab, Batavia, Illinois

The proposed High Intensity Neutrino Source at Fermilab is based on an 8 GeV linear proton accelerator which consists of a normal-conducting and a superconducting section. The normal-conducting (warm) section is composed of an ion source, a radio frequency quadrupole, a medium energy beam transport and 16 normal-conducting crossbar H-type cavities that accelerate the beam from 2.5 MeV to 10 MeV (from β=0.0744 to β=0.1422). These warm cavities are separated by superconducting solenoids enclosed in individual cryostats. Beyond 10 MeV, the design uses superconducting spoke resonators to accelerate the beam up to 8 GeV. In this paper, we illustrate the completion of the first normal-conducting crossbar h-type cavity (β=0.0744) explaining in detail the mechanical engineering aspects related to the machining and brazing processes. The radio-frequency measurements and tuning performed at Fermilab on the resonator and the comparisons with the former simulations are also discussed.

• J. Z. Zhou
  
• C. Chen, B. M. Kardon
  MIT/PSFC, Cambridge, Massachusetts

A photonic band gap (PBG) higher-order-mode (HOM) coupler is proposed as an Alternative Configuration Design (ACD) for the HOM coupler for the International Linear Collider (ILC). The PBG HOM coupler uses a two-dimensional triangular PBG structure with good axial symmetry. Simulation studies of a PBG HOM coupler show that it maintains the operating mode at 1.3 GHz with . While a PBG HOM coupler provides superior damping for all the higher order modes in principle, detailed studies of the effectiveness of HOM damping are being carried out, and results will be discussed.

• J. Rose
  
• A. Blednykh, W. Guo, P. Mortazavi, N. A. Towne
  BNL, Upton, Long Island, New York

• 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.

• E.-S. Kim
  

• B. Chung
  
• Y.-S. Cho
  KAERI, Daejon
• Y. Y. Lee
  BNL, Upton, Long Island, New York

The Proton Engineering Frontier Project (PEFP) is a research project to develop a 100 MeV, 20 mA pulsed proton linear accelerator to be used in basic/applied scientific R&D programs and industrial applications. The PEFP proposes the 1.0 GeV synchrotron accelerator as an extension of the PEFP linac, which is a 30 Hz rapid-cycling synchrotron (RCS) with the injection energy of 100 MeV. The target beam power is 87 kW at 1.0GeV in the first stage. The high intensity RCS is one of the important challenges for the spallation neutron source. The conceptual lattice design of the RCS as well as the simulations of an injection system is described in this paper.

• M. Alabau
  
• P. Bambade
  LAL, Orsay
• A. Faus-Golfe
  IFIC, Valencia
• A. Latina, D. Schulte
  CERN, Geneva

• F. Jackson
  
• R. J. Barlow, A. M. Toader
  UMAN, Manchester
• A. Latina, D. Schulte
  CERN, Geneva

• K. G. Panagiotidis
  
• A. Wolski
  Liverpool University, Science Faculty, Liverpool

• 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.

• R. P. Johnson
  
• C. M. Ankenbrandt, C. M. Bhat, M. Popovic
  Fermilab, Batavia, Illinois
• S. A. Bogacz, Y. S. Derbenev
  Jefferson Lab, Newport News, Virginia

The idea of coalescing multiple muon bunches at high energy to enhance the luminosity of a muon collider provides many advantages. It circumvents space-charge, beam loading, and wakefield problems of intense low-energy bunches while restoring the synergy between muon colliders and neutrino factories based on muon storage rings. A sampling of initial conceptual design work for a coalescing ring is presented here.

• A. Jansson
  
• V. Balbekov, D. R. Broemmelsiek, M. Hu, N. V. Mokhov, K. Yonehara
  Fermilab, Batavia, Illinois

Within the framework of the Fermilab Muon Collider Task Force, the possibility of developing a dedicated muon test beam for cooling experiments has been investigated. Cooling experiments can be performed in a very low intensity muon beam by tracking single particles through the cooling device. With sufficient muon intensity and large enough cooling decrement, a cooling demonstration experiment may also be performed without resolving single particle trajectories, but rather by measuring the average size and position of the beam. This allows simpler, and thus cheaper, detectors and readout electronics to be used. This paper discusses muon production using 400MeV protons from the linac, decay channel and beamline design, as well as the instrumentation required for such an experiment, in particular as applied to testing the Helical Cooling Channel (HCC) proposed by Muons Inc.

• D. V. Neuffer
  
• R. P. Johnson
  Muons, Inc, Batavia
• C. Y. Yoshikawa
  Fermilab, Batavia, Illinois

Common to various front end designs for a muon collider or neutrino factory are costly low frequency RF cavities used to bunch muons. In this paper we show that adding higher harmonic RF cavities to the bunching section of a muon capture channel can provide as good or better bunching efficiency than the case where only the fundamental is used. Since higher harmonic cavities are less expensive to build and operate, this approach implies significant cost savings.

• N. Solyak
  
• V. Ivanov, C. S. Mishra, K. Ranjan
  Fermilab, Batavia, Illinois

The proposed International Linear Collider (ILC) machine requires extremely small transverse emittances of the beam to achieve desired luminosity. A very precise alignment of the beamline elements, both in main linac and in beam delivery system, is required to limit the emittance growth. However, ground motion (GM) and technical noise continuously misaligns the elements and hence spoils the effect of alignment. It is thus very important to understand and analyze the effect of GM on the performance of ILC. Also, it is imperative to find an effective dynamic alignment procedure to preserve the transverse emittances in the presence of GM. In this paper we study the effect of GM and technical noise on the proposed ILC main linac. Initial alignment of the Linac is performed through one-to-one and dispersion free steering (DFS). We then study "Adaptive Alignment" method to mitigate the effects of GM and technical noise.

• A. Valishev
  
• N. Solyak
  Fermilab, Batavia, Illinois
• M. Woodley
  SLAC, Menlo Park, California

• I. Reichel
  

Designing a lattice with sufficient dynamic aperture for the ILC Damping Rings is very challenging as the lattice needs to provide a small equilibrium emittance and at the same time a large aperture for the injected beam including a large momentum acceptance. In addition outside constraints have forced layout changes in the damping ring. Some of the layout changes had an impact on the dynamic aperture. In order to better understand the changes in dynamic aperture, frequency maps are studied. Those studies can help in identifying the reason for the changed dynamic aperture and in finding a good location for the betatron tunes and determining an upper limit for the chromaticities. A summary of recent studies and suggestions improving the dynamic aperture by choosing a different tune are presented.

• R. A. Marsh
  
• M. A. Shapiro, R. J. Temkin
  MIT/PSFC, Cambridge, Massachusetts

High gradient structure design entails optimization of the gradient, while minimizing surface electric fields (associated with breakdown) and surface magnetic fields (associated with pulsed heating). Design studies are reported comparing metallic and dielectric PBG structures and standard disk-loaded waveguide. Operation in a higher order mode is considered. A variety of codes; HFSS, CST MWS, and Superfish have been used to compare and refine designs. Final design work is in preparation for a structure to be cold tested, tuned, and then processed to high gradient operation at the MIT HRC 17 GHz accelerator facility.

• M. A. Shapiro
  
• J. R. Sirigiri, R. J. Temkin
  MIT/PSFC, Cambridge, Massachusetts

We present the results of our recent research on 3D metal-wire lattices operating at microwave frequencies, with applications to advanced accelerator structures and radiation sources based on the Smith-Purcell effect. Bulk and surface electromagnetic waves supported by a diamond-like lattice are calculated using HFSS. The bulk modes are determined using primitive cell calculations. The surface mode is determined using the simulations of the stack of cells with the perfect-matching layer (PML) boundary.

• J. C. Smith
  
• P. Eliasson
  Uppsala University, Uppsala
• K. Kubo
  KEK, Ibaraki
• A. Latina, D. Schulte
  CERN, Geneva
• P. Lebrun, K. Ranjan
  Fermilab, Batavia, Illinois
• F. Poirier, N. J. Walker
  DESY, Hamburg
• P. Tenenbaum
  SLAC, Menlo Park, California

In an effort to compare beam dynamics and create a ‘‘benchmark'' for Dispersion Free Steering (DFS) a comparison was made between different International Linear Collider (ILC) simulation programs while performing DFS. This study consisted of three parts. First, a simple betatron oscillation was tracked through each code. Secondly, a set of component misalignments and corrector settings generated from one program was read into the other to confirm similar emittance dilution. Thirdly, given the same set of component misalignments DFS was performed independently in each program and the resulting emittance dilution was compared. Performance was found to agree exceptionally well in all three studies.

• R. J. Noble
  
• E. R. Colby, B. M. Cowan, C. M.S. Sears, R. Siemann, J. E. Spencer
  SLAC, Menlo Park, California

Photonic bandgap (PBG) fibers with hollow core defects have been suggested for use as laser driven accelerator structures. The modes of a periodic PBG fiber lie in a set of allowed bands. A fiber with a central vacuum defect can support so-called defect modes with frequencies in the bandgap and electromagnetic fields confined spatially near the central defect. A defect mode suitable for relativistic particle acceleration must have a longitudinal electric field in the central defect and a phase velocity near the speed of light (SOL). We explore the design of the defect geometry to support well-confined accelerating modes in such PBG fibers. The details of the surface boundary separating the defect from the surrounding matrix are found to be the critical ingredients for optimizing the accelerating mode properties. We give examples of improved accelerating modes in fiber geometries with modified defect surfaces.

• 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.

• J. S. Berg
  
• S. R. Koscielniak
  TRIUMF, Vancouver
• S. Machida
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• A. G. Ruggiero
  BNL, Upton, Long Island, New York

EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). This paper describes the design of the EMMA lattice. We begin with a description of the experimental goals that impact the lattice design. We then describe what motivated the choice for the basic lattice parameters, such as the type of cells, the number of cells, and the RF frequency. We next list the different configurations that we wish to operate the machine in so as to accomplish our experimental goals. Finally, we enumerate the detailed lattice parameters, showing how these parameters result from the various lattice configurations.

• R. B. Palmer
  
• Y. Alexahin, D. V. Neuffer
  Fermilab, Batavia, Illinois
• J. S. Berg, R. C. Fernow, J. C. Gallardo, H. G. Kirk
  BNL, Upton, Long Island, New York
• S. A. Kahn
  Muons, Inc, Batavia
• D. J. Summers
  UMiss, University, Mississippi

We propose a complete scheme for cooling a muon beam for a muon collider. We first outline the parameters required for a multi-TeV muon collider. The cooling scheme starts with the front end of the Study 2a proposed Neutrino Factory. This yields bunch trains of both muon signs. Emittance exchange cooling in upward climbing helical lattices then reduces the longitudinal emittance until it becomes possible to combine the trains into single bunches, one of each sign. Further cooling is now possible in emittance exchange cooling rings. Final cooling to the required parameters is achieved in 50 T solenoids that use high temperature superconductor. Preliminary simulations of each element will be presented.

• D. Trbojevic
  

Muon acceleration for muon collider or neutrino factory is still in the stage where further improvements are likely as a result of further study. This report presents a design of the racetrack non-scaling Fixed Field Alternating Gradient (NS-FFAG) accelerator to allow fast muon acceleration in small number of turns. The racetrack design is made of four arcs: two arcs at opposite sides have a smaller radius and are made of closely packed combined function magnets, while two additional arcs with a very large radius are used for muon extraction, injection, and RF accelerating cavities. The ends of the large radii arcs are geometrically matched at the connections to the arcs with smaller radii. The dispersion and both horizontal and vertical amplitude functions are matched at the central energy.

• D. Trbojevic
  
• I. Ben-Zvi, J. S. Berg, M. Blaskiewicz, V. Litvinenko, W. W. MacKay, V. Ptitsyn, T. Roser, A. G. Ruggiero
  BNL, Upton, Long Island, New York

Acceleration of electrons up to 10 GeV for a future electron-ion collider eRHIC (Relativistic Heavy Ion Collider) could be performed with the energy recovery linac with multiple passes. An energy recovery scheme is required if a superconducting linac is used for acceleration. We report on an attempt to make a combination of a multi-pass linac with non-scaling Fixed Field Alternating Gradient (NS-FFAG) arcs. Two NS-FFAG arcs would allow electrons to pass through the same structure with different energies. The beam will be accelerated by the superconducting linac at the top of the sine function, and returned to the front of the linac by the non-scaling FFAG. This process is repeated until the total energy of 10 GeV is reached. After collisions the beam is brought back by the NS-FFAG and decelerated before being dumped.

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

• M. K. Craddock
  
• S. R. Koscielniak
  TRIUMF, Vancouver

• J. F. Cardona
  

It's been shown in previous conferences [*,**] that action and phase jump analysis is a promising method to measure normal quadrupole components, skew quadrupole components and even normal sextupole components. In this paper, the action and phase jump analysis is evaluated using new RHIC data.

*J. Cardona,et al, Procceedings of PAC 2005, Knoxville, Tennesse.**J. Cardona,et al, Procceedings of EPAC 2004, Lucerne, Switzerland.

• A. S. Parfenova
  
• G. Franchetti, I. Hofmann, C. Omet
  GSI, Darmstadt
• S.-Y. Lee
  IUCF, Bloomington, Indiana

• I. Hofmann
  
• G. Franchetti
  GSI, Darmstadt

• E. Prat
  
• W. Decking, T. Limberg, F. Loehl
  DESY, Hamburg
• K. Honkavaara
  Uni HH, Hamburg

• A. N. Chechenin
  
• Y. Senichev, N. E. Vasyukhin
  FZJ, Julich

• Y. Senichev
  

• C. Benedetti
  
• G. Franchetti, I. Hofmann
  GSI, Darmstadt
• S. Rambaldi, G. Turchetti
  Bologna University, Bologna

We present the upgrade of the MICROMAP beam dynamics simulation library to include a 2 1/2 D space charge modeling of a 3D bunch using local slices in z. We discuss the parallelization technique, the performances, several tests and comparison with existing well-established analytical/numerical results in order to validate the code. An application to the SIS100 synchrotron of the FAIR project at GSI is outlined.

• H. Ohgaki
  
• Y. Iwasaki, T. Tomimasu
  SAGA, Tosu
• S. Koda, Y. Takabayashi, K. Yoshida
  Saga Synchrotron Light Source, Industry Promotion Division, Saga City

• Y. Sun
  
• J. Gao
  IHEP Beijing, Beijing
• Z. Y. Guo
  PKU/IHIP, Beijing

*ypsun@ihep.ac.cn

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

A method of injection analysis of small electron storage ring is introduced, and several medium emittance lattices are proposed. By analyzing the injection, working point of the lattice is selected at the vicinity of half integer resonance lines, and emittance is around 60nmrad, the linear and nonlinear properties can be satisfied for injection and store.

LIU Zu-Ping, Li Wei-Min. Progress of the NSRL Phase Two Project. In proceedings of the Second Asia Particle Accelerator Conference, Beijing, China, 2001, 235-238

• 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.

• F. Schmidt
  
• E. Forest
  KEK, Ibaraki
• P. K. Skowronski
  CERN, Geneva

• N. Sereno
  
• M. Borland
  ANL, Argonne, Illinois

In recent years, we have explored various upgrade options for the Advanced Photon Source (APS) storage ring that would provide the user community higher brightness. Increased brightness would be accomplished by reducing the emittance of the storage ring as well as increasing the stored beam current from 100 mA to 200 mA. Two upgrade lattices were developed that reduce the effective beam emittance to 1 nm from the present 2.7 nm. These lattices have reduced dynamic aperture compared to the present ring lattice, which may require a reduced emittance booster to minimize injection losses. This paper describes injection tracking simulations that explore how high the booster emittance can be and still have no losses at injection for the 1-nm ring upgrade lattices. An alternative booster lattice is presented with reduced emittance compared to the present booster lattice (65 nm). The proposed low-emittance booster lattice would add pole-face windings to the existing booster dipoles and hence would not require replacement of the existing booster magnets.

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

We present a triple-bend lattice design that uses the current APS tunnel. The new lattice has a 1 nm-rad effective emittance at 7 GeV. A forty-period symmetric optics is presented. For the benefit of some X-ray user experiments, an optics with four special straight sections of one-third the beam size of normal sections was investigated as well. The associated nonlinear optical difficulties are addressed and simulation results are presented.

• A. Xiao
  
• L. Emery
  ANL, Argonne, Illinois

We present a lattice design based on the theoretical-minimum-emittance (TME) cell for the International Linear Collider (ILC0 6.6-km 5-GeV damping ring. Several areas are discussed: momentum compaction, lattice layout, injection and extraction, circumference adjusters, phase adjuster, and dynamic aperture calculation with multipole errors.

• Y. Alexahin
  
• E. Gianfelice-Wendt
  Fermilab, Batavia, Illinois
• V. V. Kapin
  MEPhI, Moscow
• F. Schmidt
  CERN, Geneva

Turn-by-turn BPM data provide immediate information on the coupledoptics functions at BPM locations. In the case of small deviations from the known (design) uncoupled optics some cognizance of the sources of perturbation, BPM calibration errors and tilts can also be inferred without detailed lattice modelling. In practical situations, however, fitting the lattice model with the help of some optics code would lead to more reliable results. We present an algorithm for coupled optics reconstruction from TBT data on the basis of MAD-X and give examples of its application for the Fermilab Tevatron and Booster accelerators.

• P. Snopok
  
• M. Berz
  MSU, East Lansing, Michigan
• C. Johnstone
  Fermilab, Batavia, Illinois

• J.-F. Ostiguy
  
• L. Michelotti
  Fermilab, Batavia, Illinois

CHEF is both a framework and an interactive application emphasizing accelerator optics calculations. The framework supports, using a common infrastructure, multiple domains of applications: e.g. nonlinear analysis, perturbation theory, and tracking. Its underlying philosophy is to provide infrastructure with minimum hidden implicit assumptions, general enough to facilitate both routine and specialized computational tasks and to minimize duplication of necessary, complex bookkeeping tasks. CHEF was already described in recent conferences. In this paper we present a status report on the most recent developments, including issues related to its application to high energy linacs.

• M.-J. Yang
  

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

The Kapchinskij-Vladimirskij equations describe the evolution of the beam envelopes in a periodic system of quadrupole focusing cells and are widely used to help predict the performance of such systems. Being nonlinear, they are usually solved by numerical integration. There have been numerous papers describing approximate solutions with varying degrees of accuracy. We have found an exact solution for a matched beam in the limit of zero space charge. The model is FODO with a full occupancy, piecewise-constant focusing function. Our explicit result for the envelope a(z) is exact for phase advances up to 180 degrees and all other values except multiples of 180 degrees. The peak envelope size is minimized at 90 degrees. The higher stable bands require larger, very accurate, field strengths while producing significantly larger envelope excursions.

• C. Xu
  
• C. K. Allen
  LANL, Los Alamos, New Mexico
• E. Schuster
  Lehigh University, Bethlehem, Pennsylvania

• D. R. Dechow
  
• D. T. Abell, P. Stoltz
  Tech-X, Boulder, Colorado
• J. F. Amundson
  Fermilab, Batavia, Illinois
• L. Curfman McInnes, B. Norris
  ANL, Argonne, Illinois

A component-based beam dynamics application for modeling collective effects in particle accelerators has been developed. The Common Component Architecture (CCA) software infrastructure was used to compose a new Python-steered accelerator simulation from a set of services provided by two separate beam dynamics packages (Synergia and MaryLie/Impact) and two high-performance computer science packages (PETSc and FFTW). The development of the proof-of-concept application was accomplished via the following tasks:

1. addressing multilanguage interoperability in the MaryLie/Impact code with Babel;
2. creating components by making the selected software objects adhere to the Common Component Architecture protocol;
3. assemblying the components with a newly developed, Component Builder gui; and
4. characterizing the performance of the space charge (Poisson) solver that was originally used in Synergia 1.0 versus the PETSc-based space charge solver that has been developed for Synergia2.

• D. A. Dimitrov
  
• I. Ben-Zvi, X. Chang, T. Rao, J. Smedley, Q. Wu
  BNL, Upton, Long Island, New York
• D. L. Bruhwiler, R. Busby, J. R. Cary
  Tech-X, Boulder, Colorado

The work at Tech-X Corp. is supported by the U. S. Department of Energy under a Phase I SBIR grant.

• 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.

• B. W. Buckley
  
• G. Hoffstaetter
  CLASSE, Ithaca

One of the main concerns in the design of a high energy Energy Recovery Linac x-ray source is the preservation of beam emittance. Discussed is one possible source of emittance dilution due to transverse electromagnetic fields in the accelerating cavities of the linac caused by the power coupler geometry. This has already been found to be a significant effect in Cornell's ERL injector cavities if only one coupler per cavity is chosen. Here we present results of simulations for Cornell's main ERL linac with three possible coupler configurations and compare them with regards to total normalized emittance growth after one complete pass through the linac. We explain why the sign of the phase between the transverse kick and the accelerating force alternates each cavity, which leads to a cancellation of the emittance growth to acceptable values. We also investigate the effect of cavity detuning on the coupler-kick effect.

• J. Shi
  
• G. Hoffstaetter
  CLASSE, Ithaca

A self-consistant simulation method is developed for the study of coherent synchrotron radiation effects by using a perturbation expansion of retarded radiation field and the particle-in-cell method. The perturbation expansion of the radiation field is based on the fact that the time dependance of a bunch particle distribution has typically two significantly different time scales, a fast time scale related to the linear dynamics and a slow time scale of the beam-size growth due to nonlinear perturbations. Since the scale of the retardation of the radiation field is usually much shorter than the slow time scale of the particle distribution, the retardation on the slow time scale of the particle distribution is treated perturbatively while the retardation on the fast time scale is removed by transformations associated the linear lattice. With this method, the particle-radiation interaction can be calculated in configuration space without memorizing the history of the particle distribution.

• W. M. Sharp
  
• R. H. Cohen, A. Friedman, D. P. Grote, A. W. Molvik
  LLNL, Livermore, California
• J. E. Coleman, P. K. Roy, P. A. Seidl, J.-L. Vay
  LBNL, Berkeley, California
• I. Haber
  UMD, College Park, Maryland

Contamination from electrons is a concern for solenoid-focused ion accelerators being developed for experiments in high-energy-density physics (HEDP). These electrons, produced directly by beam ions hitting lattice elements or indirectly by ionization of desorbed neutral gas, can potentially alter the beam dynamics, leading to a time-varying focal spot, increased emittance, halo, and possibly electron-ion instabilities. The electrostatic particle-in-cell code WARP is used to simulate electron-cloud studies on the solenoid-transport experiment (STX) at Lawrence Berkeley National Laboratory. We present self-consistent simulations of several STX configurations to show the evolution of the electron and ion-beam distributions first in idealized 2-D solenoid fields and then in the 3-D field values obtained from probes. Comparisons are made with experimental data, and several techniques to mitigate electron effects are demonstrated numerically.

• D. Schiller
  
• S. Reiche, M. Ruelas
  UCLA, Los Angeles, California

• F.-J. Decker
  
• Y. Nosochkov, M. K. Sullivan, G. Yocky
  SLAC, Menlo Park, California

Orbit bumps in sextupoles are routinely used for tuning the luminosity in the PEP-II B-Factory. Anti-symmetric bumps in a sextupole pair generate dispersion, while symmetric bumps induce a tune shift and beta beat. By coming two of these symmetric bumps with opposite signs where the second pair is 90 degree away, the tune shift cancels and the beta beat doubles. In the low energy ring (LER) we have four sextupole pairs per arc, where pair 1 and 3 are at the same betatron phase and pair 2 and 4are 90 degree away. By making two symmetric bumps with opposite sign in pair 1 and 3 the tune shift and the beta beat outside this region cancel, BUT the LER lifetime improved by a factor of three, losses by a factor of five, and the beam-beam background in the drift chamber of the BaBar detector by 20%. Simulations showed that the phase change at the second sextupole pair introduced by the beta beat can completely cancel the third order chromaticity.

• A. C. Kabel
  
• W. Fischer
  BNL, Upton, Long Island, New York
• T. Sen
  Fermilab, Batavia, Illinois

• M. T.F. Pivi
  

We present the features of CMAD, a newly developed self-consistent code which simulates both the electron cloud build-up and related beam instabilities. By means of parallel (Message Passing Interface - MPI) computation, the code tracks the beam in an existing (MAD-type) lattice and continuously resolve the interaction between the beam and the cloud at each element location, with different cloud distributions at each magnet location. CMAD simulates single-and coupled-bunch instability, allows tune shift, dynamic aperture and frequency map analysis and the determination of the secondary electron yield instability threshold. Preliminary results are presented.

• W. Wittmer
  

The PEP II lattices are unique in their detector solenoid field compensation scheme by utilizing a set of skew quadrupoles in the IR region and the adjacent arcs left and right from the IP. Additionally the design orbit through this region is nonzero. This combined with the strong local coupling wave makes it very difficult to calculate IP tuning knobs which are orthogonal and closed. The usual approach results either in non-closure, not being orthogonal or the change in magnet strength being too big. To find a solution the set of tuning quads had to be extended which resulted having more degrees of freedom than constrains. To find the optimal set of quadrupoles which creates a linear, orthogonal and closed knob and simultaneously minimizing the changes in magnet strength, the method using Singular Value Decomposition, Response Matrices and an Adapted Moore Penrose Method had to be extended. The results of these simulations are discussed below and the results of first implementation in the machine are shown.

• Y. T. Yan
  
• Y. Cai, W. S. Colocho, F.-J. Decker
  SLAC, Menlo Park, California

For optics measurement and modeling of the PEP-II electron (HER) and position (LER) storage rings, we have been doing well with MIA* which requires analyzing turn-by-turn Beam Position Monitor (BPM) data that are resonantly excited at the horizontal, vertical, and longitudinal tunes respectively. However, in anticipating that certain BPM buttons or even pins in the PEP-II IR region will be missing for the next run starting in January 2007, we have been developing a data validation process, hoping to reduce the effect due to the reduced BPM data accuracy on PEP-II optics measurement and modeling. Besides the routine process for ranking BPM noise level through data correlation among BPMs, allowing BPMs to have linear gains and linear cross couplings, we can also check BPM data symplecticity by comparing the invariant ratios. We may also work out nonlinear BPM data correction if needed. Results on PEP-II measurement will be presented.

* Y. T. Yan, et. al. EPAC06 Proceedings, WEPCH062, (2006)

• D. Douglas
  
• K. Beard, J. Eldred, P. Evtushenko, A. Jenkins, S. W. Moore, L. Osborne, D. W. Sexton, C. Tennant
  Jefferson Lab, Newport News, Virginia

Particle beam modeling in accelerators has been the focus of much effort (at great expense) since the 1950s. Several generations of tools have resulted from this process, each leveraging both the understanding provided by predecessors and the availability of increasingly powerful computer hardware. Nonetheless, the process remains on-going, in part due to innovations in accelerator design, construction, and operation that result in machines not easily described by existing tools. We discuss a novel response to this issue, which was encountered when Jefferson Lab began operation of its energy-recovering linacs. As such machines are not conveniently described using legacy software, a machine model was been built using Microsoft Excel. This interactive simulation can query data from the accelerator, use it to compute machine parameters, analyze difference orbit data, and evaluate beam properties. It can also derive new accelerator tunings and rapidly evaluate the impact of changes in machine configuration. As it is spreadsheet-based, it can be easily user-modified in response to changing requirements. Examples for the JLab IR Upgrade FEL are presented.

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

The transverse compression and dynamics of intense charged particle beams, propagating through a periodic quadrupole lattice, play an important role in many accelerator physics applications. Typically, the compression can be achieved by means of increasing the focusing strength of the lattice along the beam propagation direction. However, beam propagation through the lattice transition region inevitably leads to a certain level of beam mismatch and halo formation. In this paper we present a detailed analysis of these phenomena using particle-in-cell (PIC) numerical simulations performed with the WARP code. A new definition of beam halo is proposed in this work that provides the opportunity to carry out a quantitative analysis of halo production by a beam mismatch.

• N. Barov
  
• S. Reiche
  UCLA, Los Angeles, California

Many simulation efforts make use of integrated numerical experiments, where the inputs and outputs of several accelerator codes are tied together. This is usually accomplished by writing custom scripts that launch the underlying programs and perform data format translation. We present a way to simplify this process by using a graphical user interface that allows one to describe the data flow in the style of the LabVIEW and Simulink environments. A module to support a new accelerator code involves writing data translators to/from a common format (SDDS or HDF5), and a function to generate an input file based on a standard way of specifying an accelerator lattice (such as Accelerator Markup Language, or AML).

• C. Montag
  

Polarized protons are injected into the Relativistic Heavy Ion Collider (RHIC) just above transition energy. When installation of a cold partial Siberian snake in the AGS required lowering the injection energy by Delta gamma=0.56, the transition energy in RHIC had to be lowered accordingly to ensure proper longitudinal matching. This paper presents lattice modifications implemented to lower the transition energy by ∆ γ_t=0.8.

• S. Prestemon
  
• S. Marks, D. Schlueter
  LBNL, Berkeley, California

• Ch. Skokos
  
• J. Laskar
  IMCCE, Paris
• Y. Papaphilippou
  CERN, Geneva

One of the main limitations for precise tune measurements using kicked turn-by-turn data is the beam decoherence, which can limit the available signal to a reduced number of turns. Applying Laskar's frequency analysis, on measurements from several beam position monitors, a fast and accurate determination of the real tune is possible. The efficiency of the method is demonstrated when applied in turn-by-turn data from the ESRF storage ring and CERN's Super Proton Synchrotron. Estimates from tracking simulations and analytical considerations are further compared with the experimental results.

• A. N. Chechenin
  
• Y. Senichev, N. E. Vasyukhin
  FZJ, Julich

• Y.-C. Chae
  
• Y. Wang, A. Xiao
  ANL, Argonne, Illinois

We recently studied a lattice achieving 1-nm emittance at the APS storage ring*. The successful design required very strong sextupoles in order to tune the machine to the desired positive chromaticity. A preliminary design of such magnets indicated saturation in the poles unless the vacuum chamber gets smaller by a factor of two compared to the existing APS chamber. Since the resistive wall impedance scales as 1/b3, where b is the radius of the chamber, we questioned how much current we can store in a single bunch at the 1-nm storage ring. In order to answer this question quantitatively, we calculated all wake potentials of impedance elements of the existing APS storage ring with the transverse dimension properly scaled but with the longitudinal dimension kept unchanged. With the newly calculated impedance of a smaller chamber, we estimated the single-bunch current limit. It turned out that the ring with a smaller chamber would not diminish the single-bunch current limit substantially. We present both wake potentials of 1-nm and the existing rings followed by the simulation results carried out for determining the accumulation limit to the ring.

* A. Xiao, "A 1-nm Lattice for the APS Storage Ring" these proceedings.

• A. H. Lumpkin
  
• W. Berg, N. Sereno, B. X. Yang, C. Yao
  ANL, Argonne, Illinois
• D. W. Rule
  NSWC, West Bethesda, Maryland

We have investigated the angular distribution patterns (far-field focus) of optical transition radiation (OTR) and optical diffraction radiation (ODR) generated by 7-GeV electron beams passing through and near an Al metal plane, respectively. The 70-μrad opening angles of the OTR patterns provide calibration factors for the system. Effects of the upstream quadrupole focusing strength on the patterns as well as polarization effects were observed. The OTR data are compared to an existing OTR single-foil model, while ODR profile results are compared to expressions for single-edge diffraction. ODR was studied with impact parameters of about 1.25 mm, close to the gamma λ?bar value of 1.4 mm for 628-nm radiation. We expect angle-pointing information along the x axis parallel to the mirror edge is available from the single-lobe ODR data as well as divergence information at the sub-100-μrad level. Experimental and model results will be presented.

• P. Snopok
  
• M. Berz
  MSU, East Lansing, Michigan
• C. Johnstone
  Fermilab, Batavia, Illinois

• M.-J. Yang
  
• J. L. Crisp, P. S. Prieto
  Fermilab, Batavia, Illinois

• K. L.F. Bane
  
• S. A. Heifets, Z. Li, C.-K. Ng, A. Novokhatski, G. V. Stupakov, R. L. Warnock
  SLAC, Menlo Park, California
• M. Venturini
  LBNL, Berkeley, California

One of the action items for the damping rings of the International Linear Collider (ILC) is to compute the broad-band impedance and, from it, the threshold to the microwave instability. For the ILC it is essential that the operating current be below threshold. Operating above threshold would mean that the longitudinal emittance of the beam would be increased. More seriously, above threshold there is the possibility of time dependent variation in beam properties (e.g. the "sawtooth" effect) that can greatly degrade collider performance. In this report, we present the status of our study including calculations of: an impedance budget, a pseudo-Green's function suitable for Haissinski equation and instability calculations, and instability calculations themselves.

• J. Bengtsson
  

In earlier work related to the NSLS-II project we have outlined a control theory approach for the dynamic aperture problem. In particular, an algorithm for the joint optimization of the Lie generator and the working point for the Poincare map. This time we report on how the Lie generator provides guidelines on acceptable magnitudes for e.g. the intrinsic nonlinear effects from insertion devices, and the nonlinear pseudo-invariant can be used to optimize the dynamic aperture. We also show how a polymorphic beam line class can be used to study the parameter dependance and rank conditions for control of optics and dynamic aperture.

bengtsson@bnl.gov