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

Recent developments in the performance of superconductors and the design of high-field superconducting dipoles have opened the possibility to extend dipole field strength to ~25 Tesla in the arc dipoles of a future hadron collider. Design issues are presented for a concept of a Tripler upgrade of LHC, in which a second dual ring would be installed over the LHC ring in the same tunnel. Proton beams from LHC would be transferred to the Tripler midway through the LHC cycle and accelerated to ~20 TeV/beam for collisions. A number of obvious issues are explored. Synchrotron radiation power would be 80 times greater, but the critical energy would come as soft X-rays rather than hard UV, and so could be absorbed locally on ~150 K photon stops following each dipole so that total refrigeration power could perhaps be no more than that for LHC. Synchrotron damping would be dramatically enhanced in the Tripler compared to LHC, with damping times of ~one hour. Alternatives for beam transfer and low-beta insertions will be discussed. Like LHC, the Tripler would access new mass scales primarily through gluon fusion. The Tripler should reach about twice the mass scale attainable with LHC.

• V.H. Ranjbar
  Fermilab, Batavia, Illinois

The Transverse turn-by-turn evolution of a bunch slice are examined considering chromatic and impedence effects. A quasi-analytical approximation is developed using perturbative expansion of Hills equation with a wake field. This approximation is compared to turn-by-turn measurements taken in the Tevatron and from this linear and second order chomaticity, and Impedence are calculated as well as beam stability thresholds.

• F. Schmidt
  CERN, Geneva

• M. Takao, M. Masaki, J. Schimizu, K. Soutome, S. Takano, H. Tanaka
  JASRI/SPring-8, Hyogo

• L. Liu, P.F. Tavares
  LNLS, Campinas

• G.H. Gillespie, W. Hill
  G.H. Gillespie Associates, Inc., Del Mar, California
• G. Coutrakon, J. Hubbard, E. Sanders
  LLU/MC, Loma Linda, California

• B.X. Yang, M. Borland, W. Guo, K.C. Harkay, V. Sajaev
  ANL, Argonne, Illinois

We present experimental studies of synchro-betatron-coupled electron beam motion in the Advanced Photon Source storage ring. We used a vertical kicker to start the beam motion. When the vertical chromaticity is nonzero, electrons with different initial synchrotron phases have slightly different betatron frequencies from the synchronous particle, resulting in a dramatic progression of bunch-shape distortion. Depending on the chromaticity and the time following the kick, images ranging from a simple vertical tilt in the bunch to more complicated twists and bends are seen with a visible light streak camera. Turn-by-turn beam position monitor data were taken as well. We found that the experimental observations are well described by the synchro-betatron-coupled equations of motion. We are investigating the potential of using the tilted bunch to generate picosecond x-ray pulses. Also note that the fast increase in vertical beam size after the kick is dominated by the internal synchro-betatron-coupled motion of the electron bunch. Experimentally this increase could be easily confused with decoherence of vertical motion if the bunch is only imaged head-on.

• M. Muñoz, D. Einfeld
  CELLS, Bellaterra (Cerdanyola del Vallès)

• L.-H. Chang, M.-C. Lin, C. Wang, M.-S. Yeh
  NSRRC, Hsinchu

• P. Wesolowski, I. Birkel, E. Huttel, A.-S. Müller, M. Pont, F. Pérez
  FZK, Karlsruhe

• H.-S. Kang, J. Choi, M.-H. Chun, K.M. Ha, J.Y. Huang, Y.-C. Kim, E.-H. Lee, T.-Y. Lee, W.W. Lee, J.-H. Suh
  PAL, Pohang, Kyungbuk

A slow global orbit feedback (SOFB) is routinely operating in the usual user service operation at PLS. The orbit feedback uses 22 correctors in each plane which have 20-bit capability for the vertical plane and 16-bit capability for the horizontal plane, and the feedback speed is 4 seconds. The orbit stability in RMS was maintained below 1 mm in both planes for one hour and 3 mm for a 12-hour operation. The BPM chamber movement due to the change of synchrotron radiation heat load mainly limits the SOFB performance. The intensity dependence of BPM electronics is well compensated by a look-up table of BPM.

• R.A. Bosch, K. Jacobs, K. J. Kleman
  UW-Madison/SRC, Madison, Wisconsin

• N.P. Abreu, N.P. Abreu
  UNICAMP, Campinas, São Paulo
• R.H.A. Farias, P.F. Tavares
  LNLS, Campinas

In the Brazilian Electron Storage Ring, we observed that modulating the phase of accelerating fields at twice the synchrotron frequency suppressed remarkably well a longitudinal coupled-bunch mode of the beam driven by one of the RF cavities. We present results of a set of systematic measurements, in single and multi-bunch mode, aimed at characterizing the effects of the modulation on the beam. We also compare those experiments with the results of tracking simulations.

• R. Wanzenberg, K. Balewski
  DESY, Hamburg

• I. Hwang, M. Yoon
  POSTECH, Pohang, Kyungbuk
• Y.J. Han, E.-S. Kim, J.S. Yang
  PAL, Pohang, Kyungbuk

• N. Mityanina
  BINP SB RAS, Novosibirsk

• N. Mityanina
  BINP SB RAS, Novosibirsk

• N. Mityanina
  BINP SB RAS, Novosibirsk

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

• C. Yao, Y.-C. Chae, N. Sereno, B.X. Yang
  ANL, Argonne, Illinois

The Advanced Photon Source (APS) particle accumulator ring (PAR) is a 325-MeV storage ring that collects and compresses linac pulse trains into a single bunch for booster injection. A vertical beam instability has been observed when only a single linac bunch is injected and the total beam charge is from 0.15 to 0.7 nC. The instability starts about 80 ms after the injection, lasts about 160 ms, and is highly reproducible. We performed spectral measurement and time-resolved imaging with both a gated-intensified camera and a streak camera in order to characterize this instability. Initial analysis of the data indicates that the instability is due to ion trapping. A stable lattice was established as result of the investigation. This report summarizes the experimental results and gives some preliminary analysis.

• A. Blednykh, S. Krinsky, B. Podobedov, J. Rose, N.A. Towne, J.-M. Wang
  BNL, Upton, Long Island, New York

• V. Balbekov
  Fermilab, Batavia, Illinois

Some results of theoretical investigations of transverse dipole instability of a rectangular bunch are reported in this paper. Such a form is characteristic of the bunch in a rectangular potential wall which is created by a barrier-shaped acceleration field. Similar regime is a major one for accumulating and cooling of antiproton beams in the Fermilab Recycler Ring. In this case, the known theory of transverse instability of a bunched beam is inapplicable directly both because of "unusual" form of phase trajectories and strong dependence of synchrotron frequency on energy. A series of equations, adequately describing the instability is derived in the paper. Exact analytical solution is obtained for space charge dominated impedance, and some approximate methods are proposed for arbitrary impedance. The theory is applied to the Fermilab Recycler Ring including a numerical simulation.

• T.-C. Fan, C.-S. Hwang, F.-Y. Lin
  NSRRC, Hsinchu

• C.-S. Hwang, C.-H. Chang, C.-K. Chang, H.-P. Chang, C.-T. Chen, H.-H. Chen, J. Chen, J.-R. Chen, Y.-C. Chien, T.-C. Fan, G.-Y. Hsiung, K.-T. Hsu, S-N. Hsu, M.-H. Huang, C.-C. Kuo, F.-Y. Lin
  NSRRC, Hsinchu

• H.-G. Lee, C.W. Chung, H.S. Han, Y.G. Jung, D.E. Kim, W.W. Lee, K.-H. Park, H.S. Suh
  PAL, Pohang, Kyungbuk

• S. Sasaki, C. Doose, E.R. Moog, M. Petra, I. Vasserman
  ANL, Argonne, Illinois
• N.V. Mokhov
  Fermilab, Batavia, Illinois

Radiation-induced magnetic field strength losses are seen in undulator permanent magnets in the two sectors with small-aperture (5 mm) vacuum chambers. Initially, simple retuning of the affected undulators could restore them to full operation. As the damage has accumulated, however, it has become necessary to disassemble the magnetic arrays and either replace magnet blocks or remagnetize and reinstall magnet blocks. Some of the damaged magnet blocks have been studied, and the demagnetization was found to be confined to a limited volume at the surface close to the electron beam. Models for the magnetic damage were calculated using RADIA* and were adjusted to reproduce the measurements. Results suggest that a small volume at the surface has acquired a weak magnetization in the opposite direction. Small magnet samples provided by NEOMAX and Shin-Etsu are being placed in the storage ring tunnel for irradiation exposure testing. Simulations of the radiation environment at the undulators have been performed.

*O. Chubar, P. Elleaume, J. Chavanne, J. Synchrotron Radiat. 5, 481 (1998).

• B. Diviacco, R. Bracco, C. Knapic, D. Millo, D.Z. Zangrando
  ELETTRA, Basovizza, Trieste
• O.V. Chubar, A. Dael, M. Massal
  SOLEIL, Gif-sur-Yvette
• Z. Martí
  LLS, Bellaterra (Cerdanyola del Vallès)

• E. Métral
  CERN, Geneva

• D. Teytelman
  SLAC, Menlo Park, California

Super B-factory designs under consideration expect to reach luminosities in the 10³⁵ - 10³⁶ range. The dramatic luminosity increase relative to the existing B-factories is achieved, in part, by raising the beam currents stored in the electron and positron rings. For such machines to succeed it is necessary to consider in the RF system design not only the gap voltage and beam power, but also the beam loading effects. The main effects are the synchronous phase transients due to the uneven ring filling patterns and the longitudinal coupled-bunch instabilities driven by the fundamental impedance of the RF cavities. A systematic approach to predicting such effects and for optimizing the RF system design will be presented. Existing as well as promising new techniques for reducing the effects of heavy beam loading will be described and illustrated with examples from the existing storage rings including PEP-II, KEKB, and DAFNE.

• M. Blaskiewicz
  BNL, Upton, Long Island, New York

A longitudinal stochastic cooling system for RHIC is under construction and partial commissioning is planned for the upcoming run. The state of the system and future plans are discussed.

• J. Wu, P. Emma, Z. Huang
  SLAC, Menlo Park, California

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, a longitudinal feedback system is required together with other diagnostics. In this paper, we study the possibility of using Coherent Synchrotron Radiation (CSR) from the chicane as the diagnostic tool for bunch length feedback. Calculations show that CSR is a good candidate, even for the non-Gaussian, double-horn longitudinal charge distribution. We further check the feasibility for low and high charge options, and also the possibility for detecting the microbunching.

• G. Moritz, J. Kaugerts
  GSI, Darmstadt
• B. Auchmann, S. Russenschuck, R. de Maria
  CERN, Geneva
• J. Escallier, G. Ganetis, A.K. Jain, A. Marone, J.F. Muratore, R.A. Thomas, P. Wanderer
  BNL, Upton, Long Island, New York
• M. Wilson
  Oxford Instruments, Accelerator Technology Group, Oxford, Oxon

• K.A. Marsh, C.E. Clayton, C. Huang, D.K. Johnson, C. Joshi, W. Lu, W.B. Mori, M. Zhou
  UCLA, Los Angeles, California
• C.D. Barnes, F.-J. Decker, M.J. Hogan, R.H. Iverson, P. Krejcik, C.L. O'Connell, R. Siemann, D.R. Walz
  SLAC, Menlo Park, California
• S. Deng, T.C. Katsouleas, P. Muggli, E. Oz
  USC, Los Angeles, California

An important aspect of plasma wake field accelerators (PWFA) is stable propagation of the drive beam. In the under dense regime, the drive beam creates an ion channel which acts on the beam as a strong thick focusing lens. The ion channel causes the beam to undergo multiple betatron oscillations along the length of the plasma. There are several advantages if the beam size can be matched to a constant radius. First, simulations have shown that instabilities such as hosing are reduced when the beam is matched. Second, synchrotron radiation losses are minimized when the beam is matched. Third, an initially matched beam will propagate with no significant change in beam size in spite of large energy loss or gain. Coupling to the plasma with a matched radius can be difficult in some cases. This paper shows how an appropriate density ramp at the plasma entrance can be useful for achieving a matched beam. Additionally, the density ramp is helpful in bringing a misaligned trailing beam onto the drive beam axis. A plasma source with boundary profiles useful for matching has been created for the PWFA experiments at SLAC.

• T. Limberg, M. Dohlus
  DESY, Hamburg

• P.S. Yoon
  Rochester University, Rochester, New York
• C.L. Bohn
  Northern Illinois University, DeKalb, Illinois
• W. Chou
  Fermilab, Batavia, Illinois

Individual particle orbits in a beam will respond to both external focusing and accelerating forces as well as internal space-charge forces. The external forces will reflect unavoidable systematic and random machine errors, or imperfections, such as jitter in magnet and radio-frequency power supplies, as well as magnet translation and rotation alignment errors. The beam responds in a self-consistent fashion to these errors; they continually do work on the beam and thereby act as a constant source of energy input. Consequently, halo formation and emittnace growth can be induced, resulting in beam degradation and loss. We have upgraded the ORBIT-FNAL package and used it to compute effects of machine errors on emittance dilution and halo formation in the existing FNAL-Booster synchrotron. This package can be applied to study other synchrotrons and storage rings, as well.

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

The geometric impedance of small-gap undulator chambers is of paramount importance for modern light sources because it may drive transverse single bunch instabilities. Analytical expressions are derived for the transverse impedance assuming a slowly tapered vacuum chamber with a confocal elliptical cross-section. The analytical results are confirmed by numerical simulations with the GdfidL Electromagnetic Field simulator and they yield the correct asymptotic limits for both round and flat chambers.

• K.Y. Ng
  Fermilab, Batavia, Illinois

• D.R. Gillingham, T. M. Antonsen, P.G. O'Shea
  IREAP, College Park, Maryland

The radiation emitted by a pulsed electron beam as it travels on a circular trajectory inside a waveguide is calculated using a 3D simulation. Forward-propagating wave equations for the fields in the waveguide are calculated by a perturbation of the Maxwell equations where the radius of curvature is large compared to the dimensions of the waveguide. These are integrated self-consistently with the distribution of charge in the beam to provide the complete fields (electric and magnetic) for all times during the passage of the beam through the waveguide and therefore are applicable to sections of any length or combinations thereof. The distribution of electrons and their momentum are also modified self-consistently so that the results may be used to estimate the effect of the radiation on the beam quality (emittance and energy spread).

• G. Bassi, J.A. Ellison
  UNM, Albuquerque, New Mexico
• R.L. Warnock
  SLAC, Menlo Park, California

We study the influence of coherent synchrotron radiation (CSR) on particle bunches traveling on arbitrary planar orbits between parallel conducting plates (shielding). The time evolution of the phase space distribution is determined by solving the Vlasov-Maxwell equations in the time domain. This provides lower numerical noise than the macroparticle method, and allows the study of emittance degradation and microbunching in bunch compressors. We calculate the fields excited by the bunch in the lab frame using a formula simpler than that based on retarded potentials.* We have developed an algorithm for solving the Vlasov equation in the beam frame using arc length as the independent variable and our method of local characteristics (discretized Perron-Frobenius operator).We integrate in the interaction picture in the hope that we can adopt a fixed grid. The distribution function will be represented by B-splines, in a scheme preserving positivity and normalization of the distribution. The transformation between lab and beam frame is carefully treated. Here we report on our implementation of the algorithm for a chicane bunch compressor with linear energy chirp and take steps to treat the nonlinear case.

*"Vlasov Treatment of Coherent Synchrotron Radiation from Arbitrary Planar Orbits" to be published in the Proceedings of ICAP04, St. Petersburg, R. Warnock, G. Bassi and J. A. Ellison.

• J.C. Dooling, F.R. Brumwell, G.E. McMichael, S. Wang
  ANL, Argonne, Illinois

The Intense Pulsed Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS) accelerates 3.2x 10¹² protons from 50 MeV to 450 MeV in a single bunch (h=1) at 30 Hz. The rf frequency varies from 2.21 MHz to 5.14 MHz during the 14.2 ms acceleration interval. To maintain stability of the bunch, phase modulation is introduced to the rf at approximately twice the synchrotron frequency (synchrotron tune is 0.0014). This phase modulation causes a parametric quadrupole oscillation to develop in the bunch, and as this occurs, the bunch spectrum shows a significant increase in high frequency content. Without phase modulation, the beam experiences an instability which results in the loss of a large fraction of the charge 2-4 ms prior to extraction. It is unclear if the stability imparted to the beam by phase modulation comes from the quadrupole oscillation or from the high frequency excitation. A longitudinal tracking code is presently being modified to include amplitude and phase modulation of the bunch. The numerical analysis will be used to compare growth rates with those observed in the machine. The results of this analysis will be important as we introduce second harmonic rf with a new third cavity in the RCS later in 2005.

• V.H. Ranjbar
  Fermilab, Batavia, Illinois

Several papers*,** have suggested possibility of using varying chromaticity to damp the head-tail instability. We test this by cycling the chromaticity sextupole magnets in the Tevatron near the synchrotron frequency to see if the head-tail stability threshold is increased. Further we compare the turn-by-turn evolution of a bunch slice in the presence of varying chromaticity to a model previously developed.

*W.-H. Cheng, A. M. Sessler, and J. S. Wurtele, Phys. Rev. Lett. 78, 4565 (1997). **T. Nakamura in Proceedings of the 1995 IEEE Particle Accelerator Conference (IEEE, Dallas, 1995), Vol. 5, p. 3100.

• Y. Zhang
  IHEP Beijing, Beijing
• K. Ohmi
  KEK, Ibaraki

BEPC will be upgraded into BEPCII, and the luminosity will be about 100 times higher. We developed a three dimensional strong-strong PIC code to study the beam-beam effects in BEPCII. The transportation through the arc is the same as that in Hirata's weak-strong code. The beam-beam force is computed directly by solving the Poisson equation using the FACR method, and the boundary potential is computed by circular convolution. The finite bunch length effect is included by longitudinal slices. An interpolation scheme is used to reduce the required slice number in simulations. The standard message passing interface (MPI) is used to parallelize the code. The computing time increases linearly with (n+1), where n is the slice number. The calculated luminosity of BEPCII at the design operating point is less than the design value. The best area in the tune space is near (0.505,0.57) according to the survey, where the degradation of luminosity can be improved.

• K. Takayama, Y. Shimosaki, K. Torikai
  KEK, Ibaraki
• J. Wei
  BNL, Upton, Long Island, New York

*K.Takayama et al., submitted to Phys. Rev. Lett., http://www.arxiv.org/pdf/physics/0412006.

• S. Chouhan, D.A. Harder, G. Rakowsky, J. Skaritka, T. Tanabe
  BNL, Upton, Long Island, New York

In this work a new concept for the construction of planar variable polarization superconductive insertion device is presented. The construction of the device with 8 mm gap and magnetic period of 26 mm is described compared with permanent magnet insertion device with the same gap & period length, as well as with previously published concepts. Advantage of this design include: (1) electrical tunability for both right and left circular and elliptical, as well as linear vertical or horizontal, (2) it requires no compensation of unwanted vertical field component and (3) used only simple windings of superconductive wire in an interlaced pattern. As a first step towards the construction of full-length device we propose to build & test a short prototype that will serve as a proof of the concept for versatile variable polarization superconductor magnet.

• T. Scarvie, A. Biocca, N. Kelez, M.C. Martin, T. Nishimura, G.J. Portmann, F. Sannibale, E. Williams
  LBNL, Berkeley, California

Beamline BL 7.2 of the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory is a beam diagnostics system that uses the synchrotron radiation (SR) emitted by a dipole magnet. It consists of two branches, in the first one the x-ray portion of the SR is used in a pinhole camera system for measuring the transverse profile of the beam. The second branch is equipped with a x-ray BPM system and with a multipurpose port where the visible and the infrared part of the SR can be used for various applications such as bunch length measurements and IR coherent synchrotron radiation experiments. The pinhole system has been commissioned at the end of 2003 and since then is in successful operation. The installation of the second branch has been completed recently and the results of its commissioning are presented in this paper together with examples of beam measurements performed at BL 7.2.

• S.P. Møller, H. Bach, F. Bødker, T.G. Christiansen, A. Elkjaer, S. Friis-Nielsen, N. Hauge, J. Kristensen, L.K. Kruse, S.P. Møller, B.R. Nielsen
  Danfysik A/S, Jyllinge

• K. Beard, S.A. Bogacz, Y.S. Derbenev
  Jefferson Lab, Newport News, Virginia
• R.P. Johnson, K. Paul, T.J. Roberts
  Muons, Inc, Batavia
• K. Yonehara
  Illinois Institute of Technology, Chicago, Illinois

The technique of using a parametric resonance to allow better ionization cooling is being developed to create small beams so that high collider luminosity can be achieved with fewer muons. In the linear channel that is studied in this effort, a half integer resonance is induced such that the normal elliptical motion of particles in x-x' phase space becomes hyperbolic, with particles moving to smaller x and larger x' as they pass down the channel. Thin absorbers placed at the focal points of the channel then cool the angular divergence of the beam by the usual ionization cooling mechanism where each absorber is followed by RF cavities. Thus the phase space of the beam is compressed in transverse position by the dynamics of the resonance and its angular divergence is compressed by the ionization cooling mechanism. We report the first results of simulations of this process, including comparisons to theoretical cooling rates and studies of sensitivity to variations in absorber thickness and initial beam conditions.

• A.S. Fisher, A. Novokhatski, J.L. Turner, U. Wienands, G. Yocky
  SLAC, Menlo Park, California
• R. Holtzapple
  Alfred University, Alfred, New York

We measured the lengths of colliding e⁺e^- bunches in the PEP-II B Factory at SLAC using various techniques. First, at several RF voltages and with both single-bunch and multibunch beams, a synchroscan streak camera measured synchrotron emission through a narrow blue filter. With 3.8 MV of RF, the length of a single positron bunch was 12 mm at low current, rising to 13 mm at 1.5 mA and 14.8 mm at 3 mA. The electrons measured 12.2 mm with little current dependence. Both are longer than the expected low-current value of 10 mm (e+) and 11 mm (e-), derived from the energy spread and the measured synchrotron tune. We also determined the length from measurements between 2 and 13 GHz of the bunch spectrum on a BPM button. After correcting for the frequency dependence of cable attenuation, we then fit the measured spectrum to that of a Gaussian bunch. With 3.8 MV, the positrons measurement gave 13.2 mm at 1.5 mA/bunch in a full ring, in agreement with the streak camera, but we found 11.4 mm for the electrons at 16.7 MV and 1 mA/bunch, lower than the streak measurement.

• M.K. Sullivan, M.H. Donald, S. Ecklund, A. Novokhatski, J. Seeman, U. Wienands
  SLAC, Menlo Park, California
• M.E. Biagini
  INFN/LNF, Frascati (Roma)

The success of the two B-Factories (PEP-II and KEKB) has encouraged us to look at design parameters for a B-Factory with a 30-50 times increase in the luminosity of the present machines (L~1e36). In order to achieve this high luminosity, the beta y* values are reduced to 3-2 mm, the bunch spacing is minimized (0.6-0.3 m) and the bunch currents are increased. Total beam currents range from 5-25 A. The interaction region (IR) of these "SuperB" designs presents special challenges. Synchrotron radiation fans from local bending in shared magnets and from upstream sources pose difficulties due to the high power levels in these fans. High-order-mode(HOM)heating, effects that have been seen in the present B-factories, will become much more pronounced with the very short bunches and high beam currents. Masking the detector beam pipe from synchrotron radiation must take into account effects of HOM power generation. Backgrounds that are a function of the luminosity will become very important. We present an initial design of an IR with a crossing angle of ± 14 mrad and include a discussion of the constraints, requirements and concerns that go into designing an IR for these very high luminosity e⁺e^- machines.

• J. Beebe-Wang, C. Montag
  BNL, Upton, Long Island, New York
• A. Deshpande
  Stony Brook University, Stony Brook
• D.J. Rondeau
  Binghamton University, State University of New York, Binghamton, New York
• B. Surrow
  MIT, Cambridge, Massachusetts

The eRHIC currently under study at BNL consists of an electron storage ring added to the existing RHIC complex. The interaction region of this facility has to provide the required low-beta focusing while accommodating the synchrotron radiation generated by beam separation close to the interaction point. In the current design, the synchrotron radiation caused by 10GeV electrons bent by low-beta triplet magnets will be guided through the interaction region and dumped 5m downstream. However, it is unavoidable to stop a fraction of the photons at the septum where the electron and ion vacuum system are separated. In order to protect the septum and minimize the backward scattering of the synchrotron radiation, an absorber and collimation system will be employed. In this paper, we first present the overview of the current design of the eRHIC interaction region with special emphasis on the synchrotron radiation. Then the initial design of the absorber and collimation system, including their geometrical and physical properties, will be described. Finally, our initial investigation of synchrotron radiation in the eRHIC interaction region, especially a simulation of the backward scattering from the absorber, will be presented.

• C. Montag
  BNL, Upton, Long Island, New York
• S.A. Bogacz, Y.S. Derbenev, L. Merminga
  Jefferson Lab, Newport News, Virginia

The Electron-Light Ion Collider ELIC proposed by Jefferson Lab aims at very high luminosities for collisions of 150 GeV protons on 7 GeV electrons. To achieve these high luminosities, very strong low-beta focusing of low-emittance beams is required. Taking advantage of the unequal design proton beam emittances in the two transverse planes, an interaction region design based on superconducting quadrupole doublets has been deveoped. Compared with the original design, this scheme provides larger beam apertures at lower magnetic fields, while potentially doubling the luminosity.

• C. Montag, B. Parker, S. Tepikian
  BNL, Upton, Long Island, New York
• D. Wang
  MIT, Middleton, Massachusetts

To facilitate the study of collisions between 10 GeV polarized electrons and 100 GeV/u heavy ions or 250 GeV polarized protons at high luminosities, adding a 10 GeV electron storage ring to the existing RHIC complex has been proposed. The interaction region of this electron-ion collider eRHIC has to provide the required low-beta focusing, while simultaneously accomodating the synchrotron radiation fan generated by beam separation close to the interaction point, which is particularly challenging. The latest design status of the eRHIC interaction region is presented.

• K. Torikai, Y.A. Arakida, J. Kishiro, T. Kono, E. Nakamura, Y. Shimosaki, K. Takayama, T. Toyama, M. Wake
  KEK, Ibaraki

An induction cavity capable of operating at a repetition rate of 1MHz with a 50% duty has been built and employed for the first induction acceleration of a proton bunch from 500MeV to 8GeV in the KEK-PS.* In this experiment, an acceleration voltage of 4.7kV and an repetition frequency of 667kHz-882kHz were required. The installed induction device consists of three induction cells, each of which can generate a bipolar induction voltage of a maximum output voltage of 2 kV with a flat-top of 300ns and a 25ns rising/falling time. Electrical characteristics of the cavity itself, such as inductance, capacitance, and resistance, have been evaluated in three independent ways: (1) excitation due to a small signal from a network analyzer, (2) excitation by a proton beam as a primary driver, (3) excitation with a actual pulse modulator in an entire system. This paper will compare these results as well as theoretical design values. A general design procedure for an induction acceleration cavity will be given.

*K.Takayama et al., submitted to Phys. Rev. Lett. http://www.arxiv.org/pdf/physics/0412006.

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

Mafia code has been used to calculate the RF properties versus the geometric parameters and dielectric permittivity for the X-band (f=9.37GHz) hybrid dielectric-iris-loaded traveling accelerating structure. The simulation results show that when the range of the permittivity is about 5-9, the new structure may have lower ratio (about 1) of peak surface electric field at the iris to axial accelerating electric field by optimizing the geometric parameters, while r, Q, r/Q of the new structure being comparable to iris-loaded accelerating structure. The experimental investigations of the permittivity of the ceramics have been made at the X-band by using the cavity perturbation technique. The measured results are in good agreement with the simulation results of Microwave Studio. Furthermore, the stability of the ceramics is examined. A number of experimental results show that the certain ceramic with permittivity of 5.78 is applied to the design of the new accelerating structure.

• C.-F. Wu, S. Dong, H. Lin
  USTC/NSRL, Hefei, Anhui

The dispersion property and the propagation characteristics of the accelerating mode (TM01 mode) and higher-order-modes about a new hybrid dielectric-iris-loaded accelerating structure have been analysed and discussed by the field matching method. Mafia code has been used to calculate the RF properties versus the geometric parameters and dielectric permittivity for the X-band (f=9.37GHz) hybrid dielectric-iris-loaded traveling accelerating structure. Some model cavities have been developed, and experimental investigations have been carried on. The above results will provided some beneficial datum for the design and manufacture of X-band hybrid dielectric-iris-loaded traveling-wave accelerating structure.

• J. Watanabe, K. Nakayama, K. S. Sato, H. Suzuki
  Toshiba, Yokohama
• M. Izawa
  KEK, Ibaraki
• A. Jackson, G. LeBlanc, K. Zingre
  ASP, Clayton, Victoria
• T. Koseki
  RIKEN/RARF/CC, Saitama
• N. Nakamura, H. Sakai, H. Takaki
  ISSP/SRL, Chiba

• N. Steinhau-Kuehl, A. Matheisen, B. Meyer, B. Petersen, ms. Schmoekel
  DESY, Hamburg

The technology of electro-polishing of super-conducting resonators made from Niobium is foreseen as basic surface preparation technology for the Xfel accelerator project at DESY. Here about 1000 resonators will be build and installed into the accelerator section. For an industrial application of this technique a quality control has to be developed and established.A method to control the acid quality and improve the life time of the acid is under development. We report on the test setup and measurements done on samples and the implementation of this quality control to the DESY electro polishing process.

• A. Gallo, D. Alesini, C. Biscari, R. Boni, F. Marcellini, M. Zobov
  INFN/LNF, Frascati (Roma)
• C. Pagani
  DESY, Hamburg

• C. Wang, L.-H. Chang, S.-S. Chang, C.-T. Chen, F.-T. Chung, F.-Z. Hsiao, G.-Y. Hsiung, K.-T. Hsu, C.-C. Kuo, H.C. Li, M.-C. Lin, R.J. Lin, Y.K. Lin, G.-H. Luo, M.H. Tsai, J.Y. Yang, T.-T. Yang, M.-S. Yeh
  NSRRC, Hsinchu

• S.A. Belomestnykh, R.P.K. Kaplan, H. Padamsee, P. Quigley, J.J.R. Reilly, J. Sears, V. Veshcherevich
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
• S. Bauer, M. Pekeler, H. Vogel
  ACCEL, Bergisch Gladbach
• L.-H. Chang, C.-T. Chen, F.-Z. Hsiao, M.-C. Lin, G.-H. Luo, C. Wang, T.-T. Yang, M.-S. Yeh
  NSRRC, Hsinchu
• E. Matias, J. Stampe, M.S. de Jong
  CLS, Saskatoon, Saskatchewan

Upon signing a technology transfer agreement with Cornell University, ACCEL began producing turn-key 500 MHz superconducting cavity systems. Four such cryomodules have been delivered, commissioned and installed in accelerators for operation to date. Two more cryomodules are scheduled for testing in early 2005. One of them will be put in operation at Canadian Light Source (CLS); the other will serve as a spare at Taiwan Light Source (TLS). The commissioning results and operational experience with the cryomodules in CESR, CLS and TLS are presented.

• S.-P. Kao, C.R. Chen, F.-Z. Hsiao, J.P. Wang
  NSRRC, Hsinchu

• H.C. Li, S. H. Chang, W. S. Chiou, F.-Z. Hsiao, Z.-D. Tsai
  NSRRC, Hsinchu

• M. Kinsho, F. Masukawa, N. Ogiwara, O. Takeda, K. Yamamoto
  JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• J. Kusano
  Japan Atomic Energy Institute, Linac Laboratory, Tokai-Mura

• K.H. Gil, J.Y. Choi, C.W. Chung, Y.-C. Kim, H.-S. Lee
  PAL, Pohang, Kyungbuk

• K.-H. Park, C.W. Chung, S.-M. Hong, S.-H. Jeong, Y.G. Jung, D.E. Kim, H.-S. Lee, W.W. Lee
  PAL, Pohang, Kyungbuk
• B.-K. Kang
  POSTECH, Pohang, Kyungbuk

• C.K. Sinclair
  Cornell University, Department of Physics, Ithaca, New York
• Y. He, C.H. Smith
  Cornell University, Ithaca, New York

The electron beam exiting an Energy Recovery Linac (ERL) is dumped close to the injection energy. This energy is chosen as low as possible while allowing the beam quality specifications to be met. As ERLs are designed for high average beam current, beam dumps are required to handle high beam power at low energy. Low energy electrons have a short range in practical dump materials, requiring the beam size at the dump face be enlarged to give acceptable power densities and heat fluxes. Cornell University is developing a 100 mA average current ERL as a synchrotron radiation source. The 13 MeV optimum injection energy requires a 1.3 MW beam dump. We present a mature design for this dump, using an array of water-cooled extruded copper tubes. This array is mounted in the accelerator vacuum normal to the beam. Fatigue failure resulting from abrupt thermal cycles associated with beam trips is a potential failure mechanism. We report on designs for a 75 kW, 750 keV tube-cooled beryllium plate dump for electron gun testing, and a 500 kW, 5 to 15 MeV copper tube dump for use with the prototype injector under development. We expect to test the beryllium dump within a year, and the higher power copper dump within 2-1/2 years.

• T. Morishita, H. Ao, T. Ito, A. Ueno
  JAERI/LINAC, Ibaraki-ken
• K. Hasegawa
  JAERI, Ibaraki-ken
• M. Ikegami, C. Kubota, F. Naito, E. Takasaki, H. Tanaka, K. Yoshino
  KEK, Ibaraki

• F. Bordry, J.-P. Burnet, F. Voelker
  CERN, Geneva

• S. Yamanaka
  NIRS, Chiba-shi
• K. Egawa, K. Endo, Z. Fang
  KEK, Ibaraki

• V. Popov, S.M. Hartman, S. Mikhailov, O. Oakeley, P.W. Wallace, Y.K. Wu
  DU/FEL, Durham, North Carolina

The on-going Duke storage ring upgrades and the development of a new booster synchrotron injection require more than 100 units of high performance unipolar and bipolar trim power supplies in the current range of -15A to +15A. However, most of the trim power supplies on the market do not deliver two critical performance features simultaneously: a high current stability and a low current noise.An in-house trim power supply development program is then put in force to design, fabricate, and test low cost linear power supplies with current stability about 100 ppm and current ripples less than 100 ppm in a broad band. A set of unipolar power supplies (0-12A) have been designed, fabricated and successfully tested. Since August, 2004 they have been used in storage ring operation with excellent performance. The prototype of bipolar power supplies (± 15 A) has been designed and tested as well. The main design principles and their performance results of both unipolar and bipolar supplies will be presented in this paper.

• G. Li, Y.G. Zhou
  USTC/NSRL, Hefei, Anhui

• P. Marchand, M.D. Diop, R.L. Lopes, J. Polian, F. Ribeiro, T. Ruan
  SOLEIL, Gif-sur-Yvette

• A. Schnase, M. Nomura, F. Tamura, M. Yamamoto
  JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Yoshii
  KEK, Ibaraki

• S. Sakanaka, K. Ebihara, S. Isagawa, M. Izawa, T. Kageyama, T. Kasuga, H. Nakanishi, M. Ono, H. Sakai, T. Takahashi, K. Umemori, S.I. Yoshimoto
  KEK, Ibaraki

• G.Y. Kurkin
  BINP SB RAS, Novosibirsk
• P. Wang
  DU/FEL, Durham, North Carolina

• A. Seville, D. Bayley, R.G. Bendall, M.G. Glover, A. Morris, J.W.G. Thomason
  CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
• D.J. Adams, I.S.K. Gardner, C.M. Warsop
  CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon

• M. Jensen, M. Maddock, S. Rains, A.V. Watkins
  Diamond, Oxfordshire
• J. Alex, M. Mueller
  Thales Broadcast & Multimedia AG, Turgi

• M. Liepe, S.A. Belomestnykh, J. Dobbins, R.P.K. Kaplan, C.R. Strohman, B.K. Stuhl
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York

A new digital control system has been developed, providing great flexibility, high computational power and low latency for a wide range of control and data acquisition applications. This system is now installed in the CESR storage ring and stabilizes the vector sum field of two of the superconducting CESR 500 MHz cavities and the output power from the driving klystron. The installed control system includes in-house developed digital and RF hardware, very fast feedback and feedforward control, a state machine for automatic start-up and trip recovery, cw and pulsed mode operation, fast quench detection, and cavity frequency control. Several months of continuous operation have proven high reliability of the system. The achieved field stability surpasses requirements.

• Z. Fang, K. Egawa, K. Endo, S. Yamanaka
  KEK, Ibaraki
• Y. Cho, T. Fusato, T. Hirashima
  DKK, Kanagawa

• F. Tamura
  JAERI/LINAC, Ibaraki-ken
• S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Yoshii
  KEK, Ibaraki
• M. Nomura, A. Schnase, M. Yamamoto
  JAERI, Ibaraki-ken

• S. Kwiatkowski, K.M. Baptiste
  LBNL, Berkeley, California

ALS is one of the first third generation synchrotron light sources which has been operating since 1993 at Berkeley Lab. In the present ALS operation scenario 1.5GeV electron beam is injected from the booster into the storage ring every 8 hours where is accelerated to the final energy of 1.9GeV. The beam decays between fills from 400mA to 200mA with the time average current of 250mA. In order to increase the beam brighthess ALS team plans to increase the beam current to 500mA and maintain it constant during machine operation ("Top-Off" mode of operation). This operation scenario will require full energy injection from the booster ring into the storage ring and constant operation of the injector (10 bunches with the total charge of 1nC every 30 to 35 seconds). In this paper we will present the results of the ALS injector RF system analysis fo Top-Off mode of operation and describe the way we intent to implement the necessary modifications to the booster RF system.

• B. A. Aminov, A. Borisov, S. K. Kolesov, H. Piel
  CRE, Wuppertal
• M. Pekeler, C. Piel
  ACCEL, Bergisch Gladbach

• E. Sobieradzki, A.E. Wheelhouse
  e2v technologies, Chelmsford, Essex

• M.L. Langlois, J.P. Buge, G. Peillex-Delphe
  TED, Vélizy Cedex

• D. Cook, M. Catucci, J. Clare, P. W. Wheeler
  University of Nottingham, Nottingham
• J.S. Przybyla
  EEV, Chelmsford, Essex

This paper is concerned with a new type of power supply for high power RF applications for CW operation. The converter is a direct topology operating with a high frequency (resonant) link. Switching losses are minimised by switching at zero current. High operating frequency allows for minimised transformer and filter size. Advantages of this topology over conventional approaches are discussed, along with the potential problems and proposed solutions. Recently, considerable interest has been shown in direct converter topologies as an alternative topology in motor drive applications. This approach offers advantages such as reduced energy storage and higher energy density compared to conventional topologies. The work presented in this paper capitalises on these advantages in other fields, namely power conversion for RF supplies. The RF power needs to be stable and predictable such that any variation has a limited impact on the accelerated beam quality. In order to meet the required output voltage specification such designs require output filters with consequent energy storage. Management of this energy in the event of a fault is necessary if destruction of the tube is to be avoided.

• A. Jackson
  ASP, Clayton, Victoria

• Z. Zhao, H. Ding, H. Xu
  SINAP, Shanghai

• P.F. Tavares, J.A. Brum
  LNLS, Campinas

• Y.E. Tan, M.J. Boland, G. LeBlanc
  ASP, Clayton, Victoria

• G. Vignola, A. Amro, M. Attal, F. Makahleh, M.M. Shehab, S. Varnasseri
  SESAME, Amman

• M.J. Ferreira, O.R. Bagnato, R.O. Ferraz, F. R. Francisco, A. L. Gobbi, R.M. Seraphim, M.B. Silva
  LNLS, Campinas

Following the upgrade of the LNLS injector system with the addition of a 500 MeV booster synchrotron,the storage ring in-vacuum ferrite injection kicker magnets started to show overheating due the interaction with high frequency electromagnetic fields induced by the electron beam. In this paper, we describe the design of a new ceramic chamber for the kickers which minimize this effect by decreasing the coupling impedance of the kickers and their interaction with the electron beam.

• X. Huang, S.-Y. Lee
  IUCF, Bloomington, Indiana
• E. Prebys, R.E. Tomlin
  Fermilab, Batavia, Illinois

The independent component analysis (ICA)* is applied to analyze simultaneous multiple turn-by-turn beam position monitor (BPM) data of synchrotrons. The sampled data are decomposed to physically independent source signals, such as betatron motion, synchrotron motion and other perturbation sources. The decomposition is based on simultaneous diagonalization of several unequal time covariance matrices, unlike the model independent analysis (MIA),** which uses equal-time covariance matrix only. Consequently the new method has advantage over MIA in isolating the independent modes and is more robust under the influence of contaminating signals of bad BPMs. The spatial pattern and temporal pattern of each resulting component (mode) can be used to identify and analyze the associated physical cause. Beam optics can be studied on the basis of the betatron modes. The method has been successfully applied to the Booster Synchrotron at Fermilab.

*A. Belouchrani et al., IEEE Trans. on Signal Processing, {\bf 45}, 434-444, (1997). **J. Irwin, et al., Phys. Rev. Lett. {\bf 82}, 1684 (1999); Chun-xi Wang, et al., Phys. Rev. ST Accel. Beams} {\bf 6}, 104001 (2003).

• C. Steier, D. Robin
  LBNL, Berkeley, California
• W. Decking
  DESY, Hamburg
• J. Laskar
  IMCCE, Paris
• L.S.N. Nadolski
  SOLEIL, Gif-sur-Yvette
• Y.K. Wu
  DU/FEL, Durham, North Carolina

The momentum aperture of a storage ring is a very important parameter that strongly influences the performance, especially the beam lifetime. For the special case of synchrotron light sources with small emittance like the Advanced Light Source (ALS), the momentum aperture depends strongly on the transverse dynamics. It is very sensitive to machine conditions such as the tunes, chromaticities, lattice symmetry, and spurious coupling, since depending on those conditions the Touschek scattered particles explore different resonance regions in the phase space. In light sources, the momentum aperture usually also depends strongly on the vertical physical aperture. Applying frequency analysis techniques in simulations and for turn-by-turn orbit measurement data provides a very powerful tool to measure and understand limitations of the dynamic momentum aperture. The techniques presented are applicable to other light sources, as well as damping rings and many types of colliders.

• Y. Papaphilippou, L. Farvacque, J.-L. Revol, V. Serriere
  ESRF, Grenoble
• S.-L. Bailey
  The College of William and Mary, Williamsburg

• C. Biscari, D. Alesini, G. Benedetti, M.E. Biagini, R. Boni, M. Boscolo, A. Clozza, G.O. Delle Monache, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, L. Pellegrino, M.A. Preger, P. Raimondi, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, C. Vaccarezza, M. Vescovi, M. Zobov
  INFN/LNF, Frascati (Roma)
• J.M. Byrd, F. Sannibale
  LBNL, Berkeley, California
• J.D. Fox, D. Teytelman
  SLAC, Menlo Park, California
• E. Levichev, P.A. Piminov, D.N. Shatilov
  BINP SB RAS, Novosibirsk
• C. Pagani
  INFN/LASA, Segrate (MI)

• P. Drumm
  CCLRC/RAL, Chilton, Didcot, Oxon

• M. Yoshii, S. Anami, E. Ezura, K. Hara, Y. Hashimoto, C. Ohmori, A. Takagi, M. Toda
  KEK, Ibaraki
• M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
  JAERI, Ibaraki-ken

• M. Tischer, K. Balewski, W. Decking, M. Seidel, L. Yongjun
  DESY, Hamburg
• V. Kuzminykh, E. Levichev, P. Vobly, K. Zolotariov
  BINP SB RAS, Novosibirsk

• A.-S. Müller, I. Birkel, B. Gasharova, E. Huttel, R. Kubat, Y.-L. Mathis, W. Mexner, D.A. Moss, F. Pérez, R. Rossmanith, P. Wesolowski, M. Wuensch
  FZK, Karlsruhe
• C. J. Hirschmugl
  UWM, Milwaukee, Wisconsin
• M. Pont
  CELLS, Bellaterra (Cerdanyola del Vallès)

• R. Rossmanith, MH. Hagelstein, B.K. Kostka, A.-S. Müller, D. Wollmann
  FZK, Karlsruhe
• T. Baumbach, A. Bernhard
  FZ Karlsruhe, Karlsruhe
• E. Steffens
  Erlangen University, Erlangen
• M. Weisser
  University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen

• S. Sakanaka, T. Mitsuhashi, T. Obina, K. Umemori
  KEK, Ibaraki

*M. Bai et al., Phys. Rev. ST Accel. Beams 3, 064001 (2000).

• G.-H. Luo, H.-P. Chang, C.-C. Kuo, K.-K. Lin, H.-J. Tsai, M.-H. Wang
  NSRRC, Hsinchu

• G. Decker, N. Sereno
  ANL, Argonne, Illinois

A method for obtaining very short pulses using modulation of the accelerating voltage gradient is described and simulation results given. The idea is to operate the two rf stations with a phase separation adjusted so that the synchronous particle resides on the crest of one of the sources. Phase modulation of the on-crest system at twice the synchrotron frequency induces a longitudinal bunch shape oscillation with significantly reduced bunch length occurring twice each synchrotron period. Pulsed and steady-state operation will be discussed using various accelerator parameters.

• C. Yao, M. Borland, A. Grelick, A.H. Lumpkin, N. Sereno
  ANL, Argonne, Illinois

A particle accumulator ring (PAR) is used at the Advanced Photon Source (APS) to collect multiple linac bunches and compress them into a 0.3-ns (rms) single bunch for booster injection. A 9.77-MHz fundamental rf system and a 117.3-MHz harmonic rf system are employed for initial beam capture and bunch length compression. Satellite bunches with very low charge form due to rf phase drifts or beam loading change. These satellites, when injected into the booster and then into the storage ring (SR), cause bunch impurity at three buckets from the target bucket. Storage ring and booster bunch cleaning was tried but proved to be difficult due to the top-up mode of operation in the storage ring and tune drift in the booster synchrotron. Recently we implemented a PAR bunch-cleaning system with tune-modulated harmonic rf knockout. Preliminary tests gave a measured SR bunch purity of better than 10-6, which shows that the cleaning method is feasible and could achieve a bunch purity goal of 10-8. This report describes the system configuration, test results, and system performance.

• J.B. Murphy, J. Bengtsson, R. Biscardi, A. Blednykh, G.L. Carr, W.R. Casey, S. Chouhan, S.B. Dierker, E. Haas, R. Heese, S. Hulbert, E.D. Johnson, C.C. Kao, S.L. Kramer, S. Krinsky, I.P. Pinayev, S. Pjerov, B. Podobedov, G. Rakowsky, J. Rose, T.V. Shaftan, B. Sheehy, J. Skaritka, N.A. Towne, J.-M. Wang, X.J. Wang, L.-H. Yu
  BNL, Upton, Long Island, New York

The National Synchrotron Light Source at BNL was the first dedicated light source facility and it has now operated for more than 20 years. During this time the user community has grown to more than 2400 users annually. To insure that this vibrant user community has access to the highest quality photon beams, the NSLS is pursuing the design of a new ultra-high brightness (~10E21) electron storage ring, tailored to the 0.3-20 KeV photon energy range. We present our preliminary design and review the critical accelerator physics design issues.

• H. Nishimura, W.E. Byrne
  LBNL, Berkeley, California

The Errant Electron Beam Interlock (EEBI) is a system that protects the vacuum chamber of the Advanced Light Source (ALS) from synchrotron light damage should the orbit, through a superconducting bend magnet (superbend), become distorted. The EEBI system monitors the vertical beam position on two BPMs, one upstream and the other downstream, of the superbend and dumps the stored beam if the orbit exceeds preset limits in either offset or angle. Discussed are the modeling studies carried out to determine how to create a large vertical bump, both for performing the test and implementing the automated test software.

• D. Robin, J.M. Byrd, P. Fischer, P.A. Heimann, D.H. Kim, S. Kwiatkowski, D. Li, F. Sannibale, C. Steier, W. Wan, W. Wittmer, A. Zholents
  LBNL, Berkeley, California

A scheme is studied for producing ps length pulses of x-ray radiation from the Advanced Light Source (ALS) using two RF deflecting cavities. The cavities create vertical displacements of electrons correlated with their longitudinal position in the bunch. The two cavities separated by 180 degrees of vertical phase advance. This allows the vertical kick from one cavity to be compensated by the vertical kick of the other. The location of the cavities corresponds to the end of one straight section and the beginning of the following straight section. Halfway between the cavities a bending magnet source is located. The radiation from the bend can be compressed to ~1 ps in duration.

• J.M. Byrd, Z. Hao, M.C. Martin, D. Robin, F. Sannibale, R.W. Schoenlein, A. Zholents, M.S. Zolotorev
  LBNL, Berkeley, California

At the Advanced Light Source (ALS), the "femtoslicing" beamline is in operation since 1999 for the production of x-ray synchrotron radiation pulses with femtosecond duration. The mechanism used for generating the short x-ray pulses induces at the same time temporary structures in the electron bunch longitudinal distribution with very short characteristic length. Such structures emit intense coherent synchrotron radiation (CSR) in the terahertz frequency range. This CSR, whose measured intensity is routinely used as a diagnostics for the tune-up of the femtoslicing experiments, represents a potential source of terahertz radiation with very interesting features. Several measurements have been performed for its characterization and in this paper an updated description of the experimental results and of their interpretation is presented.

• D. Wang, dc. Cheever, M. Farkhondeh, W.A. Franklin, W. Graves, E. Ihloff, C. Tschalaer, D. Wang, D. Wang, F. Wang, T. Zwart, J. van der Laan
  MIT, Middleton, Massachusetts
• B. Podobedov
  BNL, Upton, Long Island, New York

The study of ultra-short bunches in MIT SHR storage ring with very small momentum compactions is carried out. The ultra-short bunches are to greatly enhence the coherent radiation by many orders of magnitude. The ring lattice is resigned to reach very small momentum compaction factor down to 1·10^-5 levels. The measurement is performed with the streak camera. The various associated issues are discussed.

• F. Wang, dc. Cheever, M. Farkhondeh, W.A. Franklin, W. Graves, E. Ihloff, C. Tschalaer, D. Wang, D. Wang, T. Zwart, J. van der Laan
  MIT, Middleton, Massachusetts
• G.L. Carr, B. Podobedov
  BNL, Upton, Long Island, New York
• F. Sannibale
  LBNL, Berkeley, California

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

Recently, Zholents et al. proposed applying to the Advanced Photon Source an x-ray compression scheme based on a pair of crab cavities and asymmetric cut crystals. We have explored the feasibility and potential performance of this scheme through simulation. We used the code elegant to perform 6-D tracking, allowing us to characterize the emittance growth, which is mostly a result of sextupoles between the cavities. We also explored tolerances on alignment, phase, and voltage of the cavities; lifetime effects; tradeoffs between cavity frequency and voltage; and performance with slicing alone instead of compression. Our conclusion is that sub-picosecond rms x-ray pulse lengths should be feasible.

• W. Guo, M. Borland, K.C. Harkay, V. Sajaev, B.X. Yang
  ANL, Argonne, Illinois

The length of x-ray pulses generated by storage ring light sources is usually tens of picoseconds. For example, the value is 40 ps rms at the Advanced Photon Source (APS). Methods of x-ray pulse compression are of great interest at the APS. One possible method, per Zholents et al., is to tilt the electron bunch with deflecting rf cavities.* Alternately, we found that the electron bunch can develop a tilt after application of a vertical kick in the presence of nonzero chromaticity. After slicing, the x-ray pulse length is determined by the tilt angle and the vertical beam size. In principal, sub-picosecond pulses can be obtained at APS. To date we have observed 6 ps rms visible light pulses with a streak camera. Efforts are underway to attempt further compression of the x-ray pulse and to increase the brilliance. This method can be easily applied to any storage ring light sources to generate x-ray pulses up to two orders of magnitude shorter than the electron bunch length. In this paper, we will present the theory of bunch tilt, particularly the synchrobetatron coupling and decoherence beam dynamics, and the simulation and the experimental results will also be shown as verification.

*A. Zholents et al., NIM A 425, 385(1999).

• S. Friis-Nielsen, S.P. Møller
  Danfysik A/S, Jyllinge

• S. Hashimoto, A. Ando
  University of Hyogo, Laboratory of Advanced Science and Technology for Industry (LASTI), Kamigori-cho, Ako-gun, Hyogo
• Y. Shoji
  LASTI, Ako-gun, Hyogo
• T. Takahashi
  KURRI, Osaka

• D. Einfeld, E. Al-Dmour, J. Campmany, M. Muñoz, M. Pont, F. Pérez
  CELLS, Bellaterra (Cerdanyola del Vallès)

• M. Kumada
  NIRS, Chiba-shi
• B.I. Grishanov, E.B. Leivichev, V.V. Parkhomchuk, F.V. Podgorny, S. Rastigeev, V.B. Reva, A.N. Skrinsky, V.A. Vostrikov
  BINP SB RAS, Novosibirsk

• K. Endo, K. Egawa, Z. Fang
  KEK, Ibaraki
• S. Yamanaka
  NIRS, Chiba-shi

• M.R.W. North, A.H. Kershaw
  CCLRC/RAL/ISIS, Chilton, Didcot, Oxon

• Y. Yin
  Y.Y. Labs, Inc., Fremont, California

• J. Ning, C.-Y. Tan
  Fermilab, Batavia, Illinois

We build an electronical instrument to get the frequency response close to the pattern of transverse beam frequency response. The method is to apply 1)a time delay circuit with ADC, FIFO RAM and DAC; 2)a phase shift circuit which is an all pass filter with adjustable phase shift in the frequency range of 25kHz to 30kHz; in a feedback loop of 3)a commutating filter which is a high Q band pass filter. We can dynamically adjust the center frequency, the side band distance during the testing. With this instrument, some beam instruments can be tested without using the real beam.

• S. Pordes, J.L. Crisp, B.J. Fellenz, R.H. Flora, A. Para, A.V. Tollestrup
  Fermilab, Batavia, Illinois

The time profiles of the bunches in the Tevatron are obtained by sampling the output of a resistive wall current monitor with a 5GS/s, 2GHz bandwidth, Lecroy 6200 oscilloscope. The techniques for removing the effect of cable dispersion and for extending the dynamic range of the data by splitting the signal and using two input channels at different gains are described. The algorithms for taking these data in the time domain and deriving the momentum spread and longitudinal emittance are also given.

• J.-P. Carneiro, S. U. Hansen, A. Ibrahim, V.D. Shiltsev, J. Steimel, R.C. Webber
  Fermilab, Batavia, Illinois

• R. Thurman-Keup, E. Lorman, T. Meyer, S. Pordes
  Fermilab, Batavia, Illinois
• S. De Santis
  LBNL, Berkeley, California

The beam bunches in the Tevatron are arranged to provide gaps in time for the abort kickers to ramp to full field. The presence of even a small fraction (few 10-4)of the beam in the abort gaps can induce quenches of the superconducting magnets and inflict severe radiation damage on the silicon detectors of the experiments. Techniques for calibrating and measuring the intensity of the beam in the abort gap using synchrotron light and a gated photomultiplier tube are described. Measurements of the evolution and longitudinal profile of the beam in the abort gap are presented.

• S.R. Marques, O.R. Bagnato, Bombacini, F.O. Bombacini, M.J. Ferreira, H. J. Onisto
  LNLS, Campinas

• M. Tejima, A. Arinaga, H. Fukuma, S. Hiramatsu, T. Ieiri, I. Ishii, M. Tobiyama
  KEK, Ibaraki

• T.C. Tseng, J.-R. Chen, H.C. Ho, C.-K. Kuan, C.J. Lin, S.Y. Perng, D.-J. Wang, J. Wang
  NSRRC, Hsinchu

• M.A. Palmer, J. Dobbins, C.R. Strohman, E. Tanke
  CESR-LEPP, Ithaca, New York

A key factor in the colliding beam performance of the Cornell Electron Storage Ring (CESR) is the impact of parasitic beam-beam interactions between bunches in the two beams as they follow their electrostatically separated orbits in a single vacuum chamber. In order to better investigate the differential performance of bunches in CESR, instrumentation electronics has been developed to allow acquisition of turn-by-turn data from multiple bunches simultaneously. The electronics consists of a standardized digital board centered around an Analog Devices TigerSHARC family digital signal processor, a communications interface, and an interface to the CESR Precision Timing System. Mated to these components is an analog front end and digitizer board which is customized for the particular diagnostic device of interest. Front ends have been developed for beam position monitor, luminosity monitor, and beam profile monitor applications. We describe the design and characterization of this new hardware.

• I.P. Pinayev, S.L. Kramer, J. Rose, T.V. Shaftan
  BNL, Upton, Long Island, New York

The National Synchrotron Light Source is performing R&D of a new 3 GeV electron storage ring to be used for the facility upgrade. To satisfy the demands for the brightness and stability of the future light source a state-of-the-art diagnostics system is a necessity. We present our preliminary design with focus on the requirements for instrumentation and technical solutions to achieve them.

• R.B. Wilcox, J.W.  Staples
  LBNL, Berkeley, California
• R. Holzwarth
  Menlo Systems GmbH, Martinsried

In femtosecond pump/probe experiments using short x-ray and optical pulses, precise synchronization must be maintained between widely separated lasers in a synchrotron or FEL facility. We are developing synchronization systems using optical signals for applications requiring different ranges of timing error. For the sub-100fs range we use an amplitude modulated CW laser at 1GHz to transmit RF phase information, and control the delay through a 100m fiber by observing the retroreflected signal. Initial results show 40fs peak-to-peak error above 10Hz, and 200fs long term drift, mainly due to amplitude sensitivity in the analog mixers. For the sub-10fs range we will lock two single-frequency lasers separated by several teraHertz to a master modelocked fiber laser, transmit the two frequencies over fiber, and lock two comb lines of a slave laser to these frequencies, thus synchronizing the two modelocked laser envelopes. For attosecond synchronization we propose a stabilized, free space link using bulk lens waveguides and high peak power ultrashort pulses.

• W.J. Corbett, C. Limborg-Deprey, W.Y. Mok, A. Ringwall
  SLAC, Menlo Park, California

SPEAR 3 is equipped with an x-ray pinhole camera and a visible/UV beam line to evaluate electron beam properties. The pinhole camera has a 30 x 25 micron Ta aperture and 60% image demagnification on a phosphor screen. The image is captured by a National Instruments frame-grabber on a remote computer with a parallel video signal for control room monitoring. The visible/UV beam line features a horizontal ± 0.3 mrad ‘cold finger’ to remove the x-ray core of the beam. The remaining visible/UV light is deflected 18 degrees onto an optical bench where it is focused via refractive Cassegrain optics. The beam is then split into parallel optics for gated- and streak camera measurements. This paper describes the experimental set up and preliminary measurements obtained with both systems.

• S.F. Lin, H. Gao, P. Lu, B. Sun, J. Wang
  USTC/NSRL, Hefei, Anhui

Supported by Natural Science Foundation of China (10275062) and CAS Knowledge Innovation Project (KY4206).

• A.F. Ghalam, T.C. Katsouleas
  USC, Los Angeles, California
• E. Benedetto, F. Zimmermann
  CERN, Geneva
• V.K. Decyk, C. Huang, W.B. Mori
  UCLA, Los Angeles, California
• G. Rumolo
  GSI, Darmstadt

• J.-C. Chang, Z.-D. Tsai
  NSRRC, Hsinchu
• J.-R. Chen
  NTHU, Hsinchu
• M. Ke
  NTUT, Taipei

• Z.-D. Tsai, J.-C. Chang, C.-Y. Liu
  NSRRC, Hsinchu
• J.-R. Chen
  NTHU, Hsinchu

• M. Seidel, R. Bospflug, J. Boster, W. Giesske, U. Naujoks, M. Schwartz
  DESY, Hamburg

• C. Rathjen, S. Blanchard, B. Henrist, K. Koelemeijer, B. Libera, P. Lutkiewicz
  CERN, Geneva

• Y. Li, Y. He, M.A. Palmer
  Cornell University, Department of Physics, Ithaca, New York

In order to improve luminosity tuning and maintenance for the CLEO-c high energy physics (HEP) program at the Cornell Electron Storage Ring (CESR), a luminosity monitor using photons from radiative Bhabha events has been installed in the CESR ring. Over 10 meters of CESR vacuum chambers near the interaction region were modified to accommodate this new device. The vacuum modifications were designed to meet two criteria. First, the new vacuum chambers had to provide sufficient horizontal and vertical aperture for photons originating from the IP over a wide range of colliding beam conditions. Secondly, the new vacuum chambers required adequate safety margins for operation at beam energies up to 5.3 GeV for Cornell High Energy Synchrotron Source running. In order to be certain that the vacuum modifications would not give rise to any localized pressure bumps, a detailed calculation of the expected vacuum pressure distribution due to synchrotron radiation flux was carried out. Careful design and planning enabled a successful installation and resumption of CESR operations in record time.

• Y. Wang, L. Fan, C. Y. Guan, D. M. Jiang, J. P. Wang, W. Wei, F. Y. Zhao
  USTC/NSRL, Hefei, Anhui

• P. Marchand, M. Louvet, M. Louvet-Monsanglant, K. Tavakoli, C. Thomas-Madec
  SOLEIL, Gif-sur-Yvette
• L. Arnaudon, O. Brunner, R. Losito, P. Maesen, E. Montesinos, G. Pechaud, M.P. Prax
  CERN, Geneva
• P. Bosland, P. Bredy, S. Chel, G. Devanz
  CEA/DSM/DAPNIA, Gif-sur-Yvette

• C.-Y. Tai, J. Cormier, W. J. Espinola, Z. Han, C.H. Joshi, A. Mavanur, L.M. Racz
  Energen, Inc., Lowell, Massachusetts
• E. Daly, G.K. Davis
  Jefferson Lab, Newport News, Virginia
• K.W. Shepard
  ANL, Argonne, Illinois

Energen, Inc. has designed, built, and demonstrated several fast and slow tuners based on its magnetostrictive actuators and stepper motor. These tuners are designed for Superconducting Radio Frequency (SRF) cavities, which are important structures in particle accelerators that support a wide spectrum of disciplines, including nuclear and high-energy physics and free electron lasers (FEL). In the past two years, Energen’s work has focused on magnetostrictive fast tuners for microphonics and Lorentz detuning compensation on elliptical-cell and spoke-loaded cavities, including the capability for real-time closed-loop control. These tuners were custom designed to meet specific requirements, which included a few to 100 micron stroke range, hundreds to kilohertz operation frequency, and cryogenic temperature operation in vacuum or liquid helium. These tuners have been tested in house and at different laboratories, such as DESY, Argonne National Lab, and Jefferson Lab. Some recent results are presented in this paper.

• M. Woods, R.A. Erickson, J.C. Frisch, C. Hast, R.K. Jobe, L. Keller, T.W. Markiewicz, T.V.M. Maruyama, D.J. McCormick, J. Nelson, N. Phinney, T.O. Raubenheimer, M.C. Ross, A. Seryi, S. Smith, Z. Szalata, P. Tenenbaum, M. Woodley
  SLAC, Menlo Park, California
• D.A.-K. Angal-Kalinin, C.D. Beard, F.J. Jackson, A. Kalinin
  CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
• R. Arnold
  University of Massachusetts, Amherst
• D. Bailey
  ,
• R.J. Barlow, G.Yu. Kourevlev, A. Mercer
  UMAN, Manchester
• S.T. Boogert, A. Liapine, S. Malton, D.J. Miller, M.W. Wing
  UCL, London
• P. Burrows, G.B. Christian, C.C. Clarke, A.F. Hartin, S. Molloy, G.R. White
  Queen Mary University of London, London
• D. Burton, N. Shales, J. Smith, A. Sopczak, R. Tucker
  Microwave Research Group, Lancaster University, Lancaster
• D. Cussans
  University of Bristol, Bristol
• C. Densham, J. Greenhalgh
  CCLRC/DL, Daresbury, Warrington, Cheshire
• M.H. Hildreth
  Notre Dame University, Notre Dame, Iowa
• Y.K. Kolomensky
  UCB, Berkeley, California
• W.F.O. Müller, T. Weiland
  TEMF, Darmstadt
• N. Sinev, E.T. Torrence
  University of Oregon, Eugene, Oregon
• M.S. Slater, M.T. Thomson, D.R. Ward
  University of Cambridge, Cambridge
• Y. Sugimoto
  KEK, Ibaraki
• S.W. Walston
  LLNL, Livermore, California
• N.K. Watson
  Birmingham University, Birmingham
• I. Zagorodnov
  DESY, Hamburg
• F. Zimmermann
  CERN, Geneva

The SLAC Linac can deliver damped bunches with ILC parameters for bunch charge and bunch length to End Station A (ESA). A 10Hz beam at 28.5 GeV energy can be delivered to ESA, parasitic with PEP-II operation. During the engineering design phase for the ILC over the next 5 years, we plan to use this facility to prototype and test key components of the Beam Delivery System (BDS) and Interaction Region (IR). We discuss our plans for this ILC Test Facility and preparations for carrying out experiments related to Collimator Wakefields, Materials Damage Tests and Energy Spectrometers. We also plan an IR Mockup of the region within 5 meters of the ILC Interaction Point to investigate effects from backgrounds and beam rf higher-order modes (HOMs).

• N.V. Mokhov, A.I. Drozhdin, M.A. Kostin
  Fermilab, Batavia, Illinois

Synchrotron radiation, spray from the dumps and extraction lines, beam-gas and beam halo interactions with collimators and other components in the ILC beam delivery system create fluxes of muons and other secondaries which can exceed the tolerable levels at a detector by a few orders of magnitude. It is shown that with a multi-stage collimation system, magnetized iron spoilers which fill the tunnel and a set of masks in the detector, one can hopefully meet the design goals. Results of modeling with the STRUCT and MARS15 codes of beam loss and energy deposition effects are presented in this paper. We concentrate on collimation system and mask design and optimization, short- and long-term survivability of the critical components (spoilers, absorbers, magnets, separators, dumps), dynamic heat loads and radiation levels in magnets and other components, machine-related backgrounds and damage in collider detectors, and environmental aspects (prompt dose, ground-water and air activation).

• E.-S. Kim
  PAL, Pohang, Kyungbuk

• A. Hutton
  Jefferson Lab, Newport News, Virginia

A light source based on an Energy Recovered Linac (ERL)* consists of a superconducting linac and a transfer line that includes wigglers and undulators to produce the synchrotron light. The transfer line brings the electrons bunches back to the beginning of the linac so that their energy can be recovered when they traverse the linac a second time, ????out of phase. There is another interesting condition when the length of the transfer line is (n±1/4) ?. In this case, the electrons drift through on the zero RF crossing, and make a further pass around the transfer line, effectively doubling the circulating current in the wigglers and undulators. On the third pass through the linac, they will be decelerated and their energy recovered. The longitudinal focusing at the zero crossing is a problem, but it can be canceled if the drifting beam sees a positive energy gradient for the first half of the linac and a negative gradient for the second half (or vice versa). This paper presents a proposal to use a double chicane at the center of the linac to provide this focusing inversion for the drifting beam while leaving the accelerating and decelerating beams on crest.

*G. R. Neil et al., Phys. Rev. Let. 84, 662 2000.

• V. Litvinenko, I. Ben-Zvi
  BNL, Upton, Long Island, New York

One of the designs of a future electron-hadron collider, eRHIC, is based on a 5-10 GeV high current energy-recovery linac (ERL) with possible extension of its energy to 20 GeV. This ERL will operate with high brightness electron beams, which naturally match requirements for X-ray FELs and other next generation light sources. In this paper we discuss possible scenarios of using the eRHIC ERL in parasitic and dedicated mode for SASE, HGHG and oscillator X-ray FELs.

*http://www.agsrhichome.bnl.gov/eRHIC/, Appendix A: Linac-Ring Option

• J.H. Liu, Y.J. Pei, B. Sun, J.H. Wang, Y.L. Yang, K. Zheng
  USTC/NSRL, Hefei, Anhui

• H.G. Kirk, S.A. Kahn, H. Ludewig, R. Palmer, V. Samulyak, N. Simos, T. Tsang
  BNL, Upton, Long Island, New York
• J.R.J. Bennett
  CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
• T.W. Bradshaw, P. Drumm, T.R. Edgecock, Y. Ivanyushenkov
  CCLRC/RAL, Chilton, Didcot, Oxon
• I. Efthymiopoulos, A. Fabich, H. Haseroth, F. Haug, J. Lettry
  CERN, Geneva
• T.A. Gabriel, V.B. Graves, J.R. Haines, P.T. Spampinato
  ORNL, Oak Ridge, Tennessee
• Y. Hayato, K. Yoshimura
  KEK, Ibaraki
• K.T. McDonald
  PU, Princeton, New Jersey

We describe an experiment designed as a proof-of-principle test for a target system capable of converting a 4 MW proton beam into a high-intensity muon beam suitable for incorporation into either a neutrino factory complex or a muon collider. The target system is based on exposing a free mercury jet to an intense proton beam in the presence of a high strength solenoidal field.

• C. Thongbai, V. Jinamoon, Mr. Kangrang, K. Kusoljariyakul, S. Rimjaem, J. Saisut, T. Vilaithong
  FNRF, Chiang Mai
• M.W. Rhodes, P. Wichaisirimongkol
  IST, Chiang Mai
• H. Wiedemann
  SLAC, Menlo Park, California

Femtosecond electron and photon pulses become a tool of interesting important to study dynamics at molecular or atomic levels. Such short pulses can be generated from a system consisting of an RF-gun with a thermionic cathode, an alpha magnet as a magnetic bunch compressor, and a linear accelerator. The femtosecond electron pulses can be used directly or used as sources to produce electromagnetic radiation of equally short pulses by choosing certain kind of radiation pruduction processes. At the Fast Neutron Research Facility (Thailand), we are especially interested in production of radiation in Far-infrared and X-ray regime. In the far-infrared wavelengths which are longer than the femtosecond pulse length, the radiation is emitted coherently producing intense radiation. In the X-ray regime, development of femtosecond X-ray source is crucial for application in ultrafast science.

• E. Matias, R. Berg, T. Johnson, R. Tanner, T. Wilson, G. Wright, H.Z. Zhang
  CLS, Saskatoon, Saskatchewan

• T. Katoh, K.  Furukawa, N. Kamikubota, H. Nakagawa, J.-I. Odagiri, G.S. Shen, Y. Takeuchi, N. Yamamoto, M. Yoshii
  KEK, Ibaraki
• H. Sakaki, H. Sako, H. Takahashi, F. Tamura, H. Yoshikawa
  JAERI, Ibaraki-ken

• M. Spata, A. Cuffe, H. Fanning, T.C.O. Oren
  Jefferson Lab, Newport News, Virginia

• L.S.N. Nadolski, J. Chinkumo, K. Ho, N.L. Leclercq, M.O. Ounsy, S. Petit
  SOLEIL, Gif-sur-Yvette

The SOLEIL control system, namely TANGO developed in collaboration with ESRF, is now mature and stable. TANGO has also been chosen now by several other laboratories. High-level control applications implemented in the control room for the storage ring, the two transfer lines, and the booster will be described in this paper. Three kinds of tools for commissioning are used. First the generic TANGO tools (alarms, simple graphical control applications), which allow us to control in a simple way any TANGO Device Server. Secondly a Matlab Middle Layer (adapted from ALS and SPEAR3): Matlab is fully interconnected with TANGO; it is used primarily for writing Physics control applications. Finally Globalscreen, a commercial SCADA software devoted for building operation applications has been selected (panels for controlling or displaying setpoint, readback values, status of equipments). In addition an overview of the historical and short-term databases for the accelerators will be given. They have been developed in house and tested during the first commissioning.

• K. Hasegawa
  JAERI, Ibaraki-ken

• T.H. Uesugi, T. Furukawa, K. Noda, S. Shibuya
  NIRS, Chiba-shi

• V.A. Kvardakov, V. Barbashin, V. Kiselev, E.V. Kremyanskaya, E. Levichev, S.I. Mishnev, V. Petrov, A.N. Skrinsky, V.V. Smaluk, I. Zemlyansky
  BINP SB RAS, Novosibirsk

• D.V. Neuffer, D.R. Broemmelsiek, A.V. Burov, S. Nagaitsev
  Fermilab, Batavia, Illinois

• K. Takayama, D.A. Arakawa, Y.A. Arakida, S. Igarashi, T. Iwashita, T. Kono, E. Nakamura, M. Sakuda, H. Sato, Y. Shimosaki, M.J. Shirakata, T. Sueno, K. Torikai, T. Toyama, M. Wake, I. Yamane
  KEK, Ibaraki
• K. Horioka
  TIT, Yokohama
• A.K. Kawasaki, A. Tokuchi
  NICHICON, Shiga
• J. Kishiro
  JAERI/LINAC, Ibaraki-ken
• K. Koseki
  GUAS/AS, Ibaraki
• M.S. Shiho
  JAERI/NAKA, Ibaraki-ken
• M. Watanabe
  JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken

*K.Takayama et al., submitted to Phys. Rev. Lett., http://www.arxiv.org/pdf/physics/0412006.

• G.P. Jackson, S.D. Howe
  Hbar Technologies, LLC, West Chicago, Illinois

• Y. Yonemura, N. Ikeda, M. Matoba
  Kyushu University, Fukuoka
• M. Aiba, S. Machida, Y. Mori, A. Muto, J. Nakano, C. Ohmori, K.O. Okabe, I. Sakai, Y. Sato, A. Takagi, T. Yokoi, M. Yoshii, Y. Yuasa
  KEK, Ibaraki
• R. Taki
  GUAS/AS, Ibaraki
• T. Uesugi
  NIRS, Chiba-shi
• A. Yamazaki
  LNS, Sendai
• M. Yoshimoto
  JAERI, Ibaraki-ken

• S. Mikhailov, M.D. Busch, M. Emamian, J.F. Faircloth, S.M. Hartman, J. Li, V. Popov, G. Swift, V. Vylet, P.W. Wallace, P. Wang, Y.K. Wu
  DU/FEL, Durham, North Carolina
• O. Anchugov, N. Gavrilov, G.Y. Kurkin, Yu. Matveev, D. Shvedov, N. Vinokurov
  BINP SB RAS, Protvino, Moscow Region

This paper presents the current status of the booster synchrotron for the Duke FEL storage ring. The booster will provide full energy injection into the storage ring in a wide energy range from 0.27 to 1.2 GeV. When operating the Duke FEL storage ring as the High Intensity Gamma Source (HIGS) to produce gamma photons above 20 MeV with Compton scattering, continuous electron loss occurs. The top-off mode operation of the booster injector will enable the continuous operation of the HIGS facility by replenishing the lost electrons. The design requirement for a compact booster with the single bunch extraction capability remains a challenge for the machine development. Presently, the booster project is in the installation phase. The magnetic elements, vacuum chambers, injection and extraction kickers have been fabricated in the Budker Institute of Nuclear Physics, Russia. The diagnostic and control system is being developed in the FEL lab, Duke University. The commissioning of the booster synchrotron is planned for fall 2005.

• H. Hanaki, T. Asaka, H. Dewa, T. Kobayashi, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida
  JASRI/SPring-8, Hyogo

• H. Fukuma
  KEK, Ibaraki
• L. Wang
  BNL, Upton, Long Island, New York

• E. Benedetto, E. Benedetto
  Politecnico di Torino, Torino
• G. Franchetti
  GSI, Darmstadt
• K. Ohmi
  KEK, Ibaraki
• D. Schulte, F. Zimmermann
  CERN, Geneva

• P. Lebrun, T. Sen, J. You, Z.Y. Yuan
  Fermilab, Batavia, Illinois
• E. Todesco
  CERN, Geneva

• C.R. Chen, F.D. Chang, S.-P. Kao, Joseph. Liu, R.J. Sheu, J.P. Wang
  NSRRC, Hsinchu

• F. Tamura
  JAERI/LINAC, Ibaraki-ken
• J.C. Chiba, T. Katoh, M. Yoshii
  KEK, Ibaraki

• H. Ohgaki
  Kyoto IAE, Kyoto
• Y. Iwasaki, S. Koda, Y. Takabayashi, T. Tomimasu, K. Yoshida
  Saga Synchrotron Light Source, Industry Promotion Division, Saga City
• H. Toyokawa
  AIST, Ibaraki

• A. Adelmann
  PSI, Villigen
• R.D. Ryne, J.M. Shalf, C. Siegerist
  LBNL, Berkeley, California

• H. Shang, M. Borland
  ANL, Argonne, Illinois

ExperimentDesigner is a Tcl/Tk interface that allows users to easily design and run complicated experiments using a convenient graphical user interface (GUI). Features include: process variable monitoring, which pauses the experiment when values are out of range; user-defined initialization, execution, and finalization sequences; support of complex execution chains containing actions such as setting controls, reading values, running external programs, interacting with the user, etc.; collection of output data for convenient postprocessing; saving and loading of experiment configurations; convenient use of SDDS Toolkit programs; and execution of experiments from the command line without a GUI.

• A. Novokhatski
  SLAC, Menlo Park, California

High luminosity in electron-positron factories requires high beam currents of very short bunches. SLAC PEP-II and KEKB B-factories are progressively increasing currents and gaining more and more luminosity. Because of this the interaction of high currents and vacuum chamber elements becomes more important for the operation of the rings. High Order Modes (HOM) excited by short intense bunches propagate along the vacuum chamber, penetrating and dissipating inside vital vacuum elements like shielded bellows, vacuum valves and vacuum pumps. As a result these elements can heat up or have temperature oscillations. Often HOM heating has a resonance character. HOM heating of vacuum pumps can lead to vacuum pressure increases. High frequency modes excited by short bunches “check” the quality of the vacuum chamber by detecting small gaps, weak RF screens or weak feed-through. At these high currents even smooth tapers and smooth collimators become a source of HOM production. We will discuss the physical nature of these very interesting HOM effects.

• U. Schramm, M.H. Bussmann, D. Habs
  LMU, München
• K. Beckert, P. Beller, B.  Franzke, T. Kuehl, F. Nolden, M. Steck
  GSI, Darmstadt
• S. Karpuk
  Johannes Gutenberg University Mainz, Mainz
• S. Reinhardt, G. Saathoff
  MPI-K, Heidelberg

We report on the first laser cooling of a bunched beam of multiply charged C³⁺ ions performed at the ESR (GSI) at a beam energy of E=1.47GeV. Moderate bunching provided a force counteracting the decelerating laser force of one counterpropagating UV laser beam. This versatile type of laser cooling lead to longitudinally space-charge dominated beams with an unprecedented relative momentum spread of 10^-7. Concerning the beam energy and charge state of the ion, the experiment depicts an important intermediate step from the established field of laser cooling of ion beams at low energies toward the laser cooling scheme proposed for relativistic beams of highly charged heavy ions at the future GSI facility FAIR.

• P.J. Spiller
  GSI, Darmstadt