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wakefield

                                  
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MOPLT099 NSC KIPT Accelerator on Nuclear and high Energy Physics plasma, wiggler, vacuum, electron 761
 
  • I.S. Guk, A. Dovbnya, S.G. Kononenko, A.S. Tarasenko
    NSC/KIPT, Kharkov
  • J.I.M. Botman, M.J. Van der Wiel
    TUE, Eindhoven
  One of the main reasons for the outflow of experts in nuclear physics and adjacent areas of science from Ukraine is the absence of modern accelerating facilities, for conducting research in the present fields of interest worldwide in this area of knowledge. A qualitatively new level of research can be achieved by the construction of a new generation accelerator applying the latest developments in the field of electron beam acceleration, in particular on the basis of superconducting accelerating structures of the TESLA type. Such structures may be used for continuous, polarized electron beams, which is crucial e.g. for thin(?) experiments checking modern theoretical models of interactions of nuclear substance, and for beams with high current and extremely short pulses for research in free electron laser and neutron physics. Such a facility will create an opportunity for carrying out research representing the interest of scientists from other countries, which will promote the integration of Ukrainian science into European and worldwide research.  
 
MOPLT100 Magnetic Structure of the NSC KIPT Nuclear-and-high-energy-physics Electron Accelerator plasma, wiggler, vacuum, beamloading 764
 
  • I.S. Guk, A. Dovbnya, S.G. Kononenko, F.A. Peev, A.S. Tarasenko
    NSC/KIPT, Kharkov
  • J.I.M. Botman, M.J. Van der Wiel
    TUE, Eindhoven
  Design options of the magnetic structure of a new proposed accelerator facility at NSC KIPT with a continuous-wave electron beam are described. The accelerator represents a recirculator, based on standard TESLA superconducting accelerating sections in one or two straight sections with a length of 5 or 19 meters. The magnetic system is designed on the basis of the magnetic elements of storage ring EUTERPE, transferred by Eindhoven University to NSC KIPT. The focusing and dispersion functions for several design choices of the magnetic structure are reported. Modeling of the beam movement in the accelerator has been carried out; the beam parameters during acceleration and on accelerator output have been calculated.  
 
MOPLT101 Performances of the Beam Generated by Metal-Dielectric Cathodes in RF Electron Guns wiggler, gun, electron, beamloading 767
 
  • I.V. Khodak, I.V. Khodak, V.A. Kushnir
    NSC/KIPT, Kharkov
  The paper describes results of the experimental research of the metal-dielectric cathode operation in RF electron gun. Application of these cathodes permits RF guns to generate intense beams with nanosecond current pulse duration. Electron beam is extracted from plasma sheath developed during the surface vacuum flashover dielectric. Simulated and experimental parameters of the beam obtained at the single-cavity RF gun output are summarized in the paper. The beam formation and its interaction with microwave field of high strength are analyzed qualitatively. Results are compared with experimental results obtained before in the 1.5-cavity RF electron gun. First experimental results on electron beam generation by the RF gun with a ferroelectric cathode are discussed in the paper.  
 
MOPLT102 To the Problem of Wake-field Excitation for Advanced Accelerator Concept wiggler, gun, electron, beamloading 770
 
  • I.N. Onishchenko, V. Kiselev, A. Linnik, N. Onishchenko, G. Sotnikov
    NSC/KIPT, Kharkov
  • V. Ushkov
    RRC Kurchatov Institute, Moscow
  The advanced accelerator concept to use the wake-fields exited in dielectric by a sequence of electron bunches for high-gradient particle acceleration has been proposed and investigated in [*-***]. Two essential merits are being exploited. First of them [**] is the excitation by a regular sequence of electron bunches that allows superposing coherently the wake-fields excited by each bunch. The second one [***] concludes to multi-mode operation that leads to peaking of the resulting HF-field that is represented by a sequence of spikes of alternative signs with essentially higher amplitude comparatively to only principle mode excitation. The recent works performed in NSC/KIPT on theoretical studies, simulation, and experimental investigations of the wake-fields excitation by a train of 2 MeV electron bunches in a dielectric waveguide are presented. Transition and Cerenkov radiation excited by short bunches in a limited dielectric medium was theoretically investigated. The measurements of wake-fields output power and the electron energy spectrum were experimentally performed.

* W.Gai, P.Schoessow, B.Cole et al. Phys. Rev. Lett. 61, 2756 (1988) ** I.N.Onishchenko, V.A.Kiselev, G.V.Sotnikov et al. Proc. 1995 Particle Accelerator Conf., p. 782-3*** T.B.Zhang, J.L.Hirshfield, T.C.Marshall et al Proc. 1997 Particle Accelerator Conf., V.42, No.3, p.1341

 
 
MOPLT103 Radiation Resistant Magnetic Sensors for Accelerators wiggler, gun, electron, radiation 773
 
  • I. Bolshakova, R. Holyaka
    LPNU, Lviv
  • S. Kulikov
    JINR, Dubna, Moscow Region
  • M. Kumada
    NIRS, Chiba-shi
  • C. Leroy
    CERN, Geneva
  The technology of obtaining the radiation resistant magnetic sensors, which characteristics remain stable under the irradiation with high dose of fast neutrons was designed. Radiation resistant sensors are developed on the base of InSb. While irradiation with neutron flux of 1010 n*cm-2*c-1 with energies 0.1…13 MeV, with the thermal neutrons part in the general flux of 20% and intermediate fluxes of 25%, the main sensors’ characteristics, that is their sensitivity to the magnetic field, change no more than for 0.05% up to the fluence of 1*1015 n*cm-2 and no more than for 1% up to the fluence of 3*1016 n*cm-2. Radiation resistant sensors are used for development of magnetic field monitoring system with measuring channels accuracy of 0,01%, which have a function of temperature measurement with the accuracy of 0.1 С at the place of sensor location, moreover, it has self diagnostics and self correction functions. This system passed the long-term testing of continuous 3 months operation at the Neutron Physics Laboratory, JINR, Dubna at the IBR-2 neutron reactor.  
 
MOPLT104 Quantitative Optimisation Studies of the Muon Front-End for a Neutrino Factory wiggler, gun, electron, radiation 776
 
  • S.J. Brooks
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  In a Neutrino Factory, short proton pulses hit a target, producing pions at widely varying angles and energies. Efficient pion capture is required to maximise the yield of decayed muons, which proceed via acceleration stages into a muon storage ring to produce neutrinos. This paper presents optimisation of a solenoidal decay channel designed for high-emittance pions, based on schemes from CERN and RAL. A non-linear tracking code has been written to run under an optimisation algorithm where every beamline element can be varied, which is then deployed as a distributed computing project. Some subsequent stages of muon beamline are also simulated, including RF and non-RF phase-rotation techniques and in one option, initial muon acceleration to 400MeV. The objective is to find optimal transmissions for each front-end concept.  
 
MOPLT105 Implementation of MICE at RAL wiggler, gun, electron, radiation 779
 
  • P. Drumm
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The Muon Ionisation Cooling Experiment (MICE) is motivated by the vision of the neutrino factory (NF). The cost and practicality of the NF depends on an early control of the emittance of the muon beam that will be accelerated and stored to produce the neutrino beams. A number of possibilities for transverse cooling of the emittance have been proposed including ionisation cooling. In such a concept, the muon beam is alternatively slowed down in cryogenic absorbers (energy loss by ionisation) and then re-accelerated in RF cavities to replace the lost energy. This process reduces the transverse momentum of the beam while maintaining the average momentum in the z-direction. The energy absorbing material should be characterised by a high stopping power and low multiple scattering: The material of choice is liquid hydrogen. MICE will replicate a piece of the NF cooling channel. The engineering of a safe system with thin windows for the containment of the liquid hydrogen and other features needed to safely operate will test the practical application of the cooling scheme and its performance. MICE is proof of principle for this untried technology. The paper reviews progress in MICE and the plans for its implementation at RAL.

The MICE Collaboration

 
 
MOPLT106 MICE: the Muon Ionisation Cooling Experiment wiggler, gun, electron, radiation 782
 
  • M. Ellis
    Imperial College of Science and Technology, Department of Physics, London
  The provision of intense stored muon beams would allow the properties of neutrinos to be measured precisely and provide a route to multi-TeV lepton-anti-lepton collisions. The short muon-lifetime makes it impossible to employ traditional cooling techniques while maintaining the muon-beam intensity. Ionisation cooling, a process in which the muon beam is passed through a series of liquid hydrogen absorbers followed by accelerating RF-cavities, is the proposed cooling technique. The international Muon Ionisation Cooling Experiment (MICE) collaboration proposes to perform an engineering demonstration of ionisation cooling. The MICE cooling channel, the instrumentation and the implementation at the Rutherford Appleton Laboratory is described together with the predicted performance of the channel and the measurements that will be made.  
 
WEPLT158 Direct Measurement of the Resistive Wakefield in Tapered Collimators electron, sextupole, optics, proton 2209
 
  • P. Tenenbaum
    SLAC, Menlo Park, California
  • D. Onoprienko
    Brunel University, Middlesex
  The transverse wakefield component arising from surface resistivity is expected to play a major role in the beam dynamics of future linear colliders. We report on a series of experiments in which the resistive wakefield was measured in a series of tapered collimators, using the Collimator Wakefield beam test facility at SLAC. In order to separate the contributions of geometric and resistive wakefields, two sets of collimators with identical geometries but different resistivities were measured. The results are in agreement with the theoretical prediction for the high-resistivity (titanium) collimators, but in the case of low-resistivity (copper) collimators the resistive deflections appear to be substantially larger than predicted.  
 
WEPLT159 Linear Vlasov Analysis for Stability of a Bunched Beam electron, sextupole, optics, proton 2212
 
  • R.L. Warnock, G.V. Stupakov
    SLAC, Menlo Park, California
  • J.A. Ellison
    UNM, Albuquerque, New Mexico
  • M. Venturini
    LBNL, Berkeley, California
  We study the linearized Vlasov equation for a bunched beam subject to an arbitrary wake function. Following Oide and Yokoya, the equation is reduced to an integral equation expressed in angle-action coordinates of the distorted potential well. Numerical solution of the equation as a formal eigenvalue problem leads to difficulties, because of singular eigenmodes from the incoherent spectrum. We rephrase the equation so that it becomes non-singular in the sense of operator theory, and has only regular solutions for coherent modes. We report on a code that finds thresholds of instability by detecting zeros of the determinant of the system as they enter the upper-half frequency plane, upon increase of current. Results are compared with a time-domain integration of the nonlinear Vlasov equation, and with experiment, for a realistic wake function for the SLC damping rings.  
 
WEPLT167 A Cure for Multipass Beam Breakup in Recirculating Linacs electron, sextupole, optics, proton 2215
 
  • B.C. Yunn
    Jefferson Lab, Newport News, Virginia
  We investigate a method to control the multipass dipole beam breakup instability in a recirculating linac including energy recovery. Effectiveness of an external feedback system for such a goal is shown clearly in a simplified model. We also verify the theoretical result with a simulation study.  
 
WEPLT168 ORBIT Benchmark of Space-charge-induced Emittance Growth in the CERN PS electron, sextupole, optics, proton 2218
 
  • S.M. Cousineau, J.A. Holmes
    ORNL/SNS, Oak Ridge, Tennessee
  • E. Métral
    CERN, Geneva
  Particle tracking codes provide an invaluable tool in the design and operation of high intensity machines. An important task in the development of these codes is the validation of the space charge models through benchmark with experimental data. Presented here are benchmarks of the ORBIT particle tracking code with recent measurements of space-charge-induced transverse emittance growth in the CERN PS machine. Benchmarks of two experimental data sets are performed: Integer resonance crossing, and Montague resonance crossing.  
 
WEPLT169 Benchmark and Threshold Analysis of Longitudinal Microwave Instability in the PSR electron, sextupole, optics, collider 2221
 
  • S.M. Cousineau, J.A. Holmes
    ORNL/SNS, Oak Ridge, Tennessee
  • C. Beltran, R.J. Macek
    LANL/LANSCE, Los Alamos, New Mexico
  A set of inductive inserts used to provide passive longitudinal space charge compensation in the Los Alamos Proton Storage Ring cause a strong microwave instability in the beam when the inductors are at room temperature. We use the ORBIT code to perform benchmarks of the microwave instability dynamics, including the mode spectrum and the instability growth time. Additionally, we analyze the experimental instability intensity threshold and compare it with the simulated threshold. For all parameters benchmarked, results of simulations are in good agreement with the experimental data.  
 
WEPLT170 Injection Schemes for Self Consistent Space Charge Distributions electron, sextupole, optics, collider 2224
 
  • V.V. Danilov, S.M. Cousineau, S. Henderson, J.A. Holmes, M. Plum
    ORNL/SNS, Oak Ridge, Tennessee
  This paper is based on recently found sets of self-consistent 2D and 3D time-dependent space charge distributions. A subset of these distributions can be injection-painted into an accumulator ring, such as Spallation Neutron Source Ring, to produce periodic space charge conditions. The periodic condition guarantees zero space-charge-induced halo growth and beam loss during injection. Practical aspects of such schemes are discussed, and simulations of a few specific cases are presented.  
 
WEPLT171 Rotating Electromagnetic Field Trap for High Temperature Plasma and Charge Confinement electron, sextupole, optics, collider 2227
 
  • V.V. Danilov
    ORNL/SNS, Oak Ridge, Tennessee
  This paper demonstrates that there exists a special combination of oscillating electromagnetic fields capable of trapping ultra high charge densities. Trapped particles undergo stable motion when their frequencies of oscillation are much higher than that of the ocillating field. Contrary to conventional electromagnetic traps, the motion in this dynamic trap is stable for arbitrarily high electromagnetic field amplitudes. This, in turn, leads to the possibility of using enormous electric and magnetic fields from RF or laser sources to confine dense ultrahigh temperature plasmas and particle beams.  
 
WEPLT172 Design & Handling of High Activity Collimators &Ring Components on the SNS electron, sextupole, optics, collider 2230
 
  • G.R. Murdoch, D. Crisp, S. Henderson, M. Holding, K. Potter, T. Roseberry
    ORNL/SNS, Oak Ridge, Tennessee
  Design & Handling of High Activity Collimators on the SNS*G Murdoch,S Henderson, K Potter,T Roseberry,Oak Ridge National Laboratory, USA,H Ludewig, N Simos, Brookhaven National Laboratory, USAJ Hirst, Rutherford Appleton Laboratory,UK, The Spallation Neutron Source accelerator systems will provide a 1GeV, 1.44MW proton beam to a liquid mercury target for neutron production. The expected highest doses to components are in the collimator regions. This paper presents the mechanical engineering design of a typical collimator highlighting the design features incorporated to assist with removal once it is activated. These features include shielding and lifting fixtures but more importantly a double contained flexible water system incorporating remote water couplings.Also presented is a mechanism that allows axial removal of vacuum bellows and its associated vacuum clamps.*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.  
 
WEPLT174 Higher Order Hard Edge End Field Effects electron, sextupole, optics, collider 2233
 
  • J.S. Berg
    BNL, Upton, Long Island, New York
  In most cases, nonlinearities from magnets must be properly included in tracking and analysis to properly compute quantities of interest, in particular chromatic properties and dynamic aperture. One source of nonlinearities in magnets that is often important and cannot be avoided is the nonlinearity arising at the end of a magnet due to the longitudinal variation of the field at the end of the magnet. Part of this effect is independent of the shape of the end. It is lowest order in the body field of the magnet, and is the result of taking a limit as the length over which the field at the end varies approaches zero. This is referred to as a hard edge" end field. This effect has been computed previously to lowest order in the transverse variables. This paper describes a method to compute this effect to arbitrary order in the transverse variables, under certain constraints. The results of using this hard edge model are compared with performing the computation with finite-length end fields, as well as to the lowest-order hard-edge end field model.  
 
WEPLT177 Analysis of Electron Cloud at RHIC sextupole, optics, electron, collider 2236
 
  • U. Iriso, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, H.-C. Hseuh, R. Lee, S. Peggs, L. Smart, D. Trbojevic, S.Y. Zhang
    BNL, Upton, Long Island, New York
  • G. Rumolo
    GSI, Darmstadt
  Pressure rises with high intense beams are becoming the main luminosity limitation at RHIC. Observations during the latest runs show beam induced electron multipacting as one of the causes for these pressure rises. Experimental studies are carried out at RHIC using devoted instrumentation to understand the mechanism leading to electron clouds. Possible cures using NEG coated beam pipes and solenoids are experimentally tested. In the following, we report the experimental electron cloud data and analyzed the results using computer simulation codes.  
 
WEPLT181 Measurement of Multipole Strengths from RHIC BPM Data sextupole, optics, electron, collider 2239
 
  • R. Tomas, M. Bai, W. Fischer
    BNL, Upton, Long Island, New York
  • F. Franchi, G. Rumolo
    GSI, Darmstadt
  Recently resonance driving terms were successfully measured in the CERN SPS and the BNL RHIC from the Fourier spectrum of BPM data. Based on these measurements a new analysis has been derived to extract multipole strengths.In this paper we present experimental measurements of sextupolar and skew quadrupolar strengths carried out at RHIC. Also discussed is the possibility of a non-destructive measurement using an AC dipole.  
 
WEPLT182 Non-linear Modeling of the RHIC Interaction Regions sextupole, optics, electron, collider 2242
 
  • R. Tomas, W. Fischer, A.K. Jain, Y. Luo, F.C. Pilat
    BNL, Upton, Long Island, New York
  For RHIC's collision lattices the dominant sources of transverse non-linearities are located in the interaction regions. The field quality is available for most of the magnets in the interaction regions from the magnetic measurements, or from extrapolations of these measurements. We discuss the implementation of these measurements on the MADX models of the Blue and the Yellow rings and their impact on beam stability.  
 
WEPLT183 Clearing of Electron Cloud in SNS sextupole, optics, collider, beamloading 2245
 
  • L. Wang, Y.Y. Lee, D. Raparia, J. Wei, S.Y. Zhang
    BNL, Upton, Long Island, New York
  In this paper we describe a mechanism using the clearing electrodes to remove the electron cloud in the Spallation Neutron Source (SNS) accumulator ring, where strong multipacting could happen at median clearing fields. A similar phenomenon was reported in an experimental study at Los Alamos laboratory's Proton Synchrotron Ring (PSR). We also investigated the effectiveness of the solenoid's clearing mechanism in the SNS, which differs from the short bunch case, such as in B-factories.  
 
WEPLT184 Preliminary Estimation of the Electron Cloud in RHIC sextupole, optics, electron, collider 2248
 
  • L. Wang, P. He, J. Wei
    BNL, Upton, Long Island, New York
  Electron cloud due to beam induce multipacting is suspected to be one of the source of pressure rises in RHIC. This paper estimates the possible electron cloud in RHIC. Various parameters related electron multipacting has been investigated.  
 
THXCH01 Achieving Sub-micron Stability in Light Sources sextupole, optics, collider, beamloading 211
 
  • M. Böge
    PSI, Villigen
  One of the major goals for present and future light sources is to achieve sub-micron orbit stability of the electron beam at the photon beam source points over a large frequency range. This puts tight constraints on the design of the various accelerator components like girders, magnets, power supplies and diagnostic hardware. Fast orbit feedbacks systems based on high performance RF- and X-BPMs become essential to suppress residual orbit distortions. Furthermore the "top-up" operation mode which guaranties a constant electron beam current and thus a constant heat load in 3rd generation light sources is one of the key ingredients to reach sub-micron stability.  
Video of talk
Transparencies
 
THOACH01 SPEAR3 Commissioning sextupole, collider, beamloading, beamlosses 216
 
  • J.A. Safranek, S. Allison, P. Bellomo, W.J. Corbett, M. Cornacchia, E. Guerra, R.O. Hettel, D. Keeley, N. Kurita, D.J. Martin, P.A. McIntosh, H. Morales, G.J. Portmann, F.S. Rafael, H. Rarback, J.J. Sebek, T. Straumann, A. Terebilo, J. Wachter, C. Wermelskirchen, M. Widmeyer, R. Yotam
    SLAC/SSRL, Menlo Park, California
  • M.J. Boland, Y.E. Tan
    ASP, Melbourne
  • J.M. Byrd, D. Robin, T. Scarvie, C. Steier
    LBNL/ALS, Berkeley, California
  • M. Böge
    PSI, Villigen
  • H.-P. Chang, C.-C. Kuo, H.-J. Tsai
    NSRRC, Hsinchu
  • W. Decking
    DESY, Hamburg
  • M.G. Fedurin, P. Jines
    LSU/CAMD, Baton Rouge, Louisiana
  • K. Harkay, V. Sajaev
    ANL/APS, Argonne, Illinois
  • S. Krinsky, B. Podobedov
    BNL/NSLS, Upton, Long Island, New York
  • L.S. Nadolski
    SOLEIL, Gif-sur-Yvette
  • A. Ropert
    ESRF, Grenoble
  • M. Yoon
    POSTECH, Pohang, Kyungbuk
  Starting in April, 2003, the SPEAR2 storage ring was removed and replaced with a new 500 mA, 3 GeV light source, SPEAR3. The SPEAR2 storage ring had been in use for high energy physics, then synchrotron radiation since 1972. Commissioning of SPEAR3 started on December 8, 2003 and synchrotron radiation will be delivered to the first users on March 8, 2004. SPEAR3 commissioning will be reviewed, including discussion of diagnostics, orbit control, optics correction and high current studies.  
Video of talk
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THOACH02 Commissioning of the 500 MeV Injector for MAX-lab sextupole, collider, beamloading, beamlosses 219
 
  • S. Werin, Å. Andersson, M. Bergqvist, M. Brandin, M. Demirkan, M. Eriksson, L.-J. Lindgren, L. Malmgren, H. Tarawneh, E.J. Wallén
    MAX-lab, Lund
  • B. Anderberg
    AMACC, Uppsala
  • G. Georgsson
    Danfysik A/S, Jyllinge
  • G. LeBlanc
    ASP, Melbourne
  A 500 MeV new injector system for the storage rings MAX I, II and III have been installed during the winter 2003-4 at MAX-lab. The system consists of two linacs at 125 MeV each, using SLED, and a recirculating system such that the electrons pass the linacs twice, thus reaching a final energy of 500 MeV. The system is injected by a thermionic RF-gun. The commissioning of the complete system will be performed in the spring 2004.  
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THOACH03 Top-up Operation at SPring-8 - Towards Maximizing the Potential of a 3rd Generation Light Source injection, collider, beamloading, beamlosses 222
 
  • H. Tanaka, T. Aoki, T. Asaka, S. Daté, K. Fukami, Y. Furukawa, H. Hanaki, N. Hosoda, T. Kobayashi, N. Kumagai, M. Masaki, T. Masuda, S. Matsui, A. Mizuno, T. Nakamura, T. Nakatani, T. Noda, T. Ohata, H. Ohkuma, T. Ohshima, M. Oishi, S. Sasaki, J. Schimizu, M. Shoji, K. Soutome, M. Suzuki, S. Suzuki, S. Takano, M. Takao, T. Takashima, H. Takebe, K. Tamura, R. Tanaka, T. Taniuchi, Y. Taniuchi, K. Tsumaki, A. Yamashita, K. Yanagida, H. Yonehara, T. Yorita
    JASRI/SPring-8, Hyogo
  • M. Adachi, K. Kobayashi, M. Yoshioka
    SES, Hyogo-pref.
  Top-up operation maximizes research activities in a light source facility by an infinite beam lifetime and photon beam stability. We have been improving the SPring-8 accelerators to achieve the ideal top-up operation. For the perturbation-free injection, we adjusted the magnetic field shape of four bump magnets to close the bump orbit, and introduced a scheme to suppress the stored beam oscillation induced by the nonlinearlity of sextupole magnets. These reduced the horizontal oscillation down to a third of the stored beam size. For the loss-free injection, beam collimators were installed upstream of the injection line. This realized the injection efficiency of ~100% under the restricted gap condition of in-vacuum insertion devices (ID). Since autumn 2003, we have been injecting the beams keeping the photon beam shutters opened and ID gaps closed. We developed a bunch-by-bunch feedback system to reduce the beam loss further with all the ID gaps fully closed by lowering the operating chromaticity. The operation with constant stored current is scheduled in June 2004. We present the overview and progress of the SPring-8 top-up operation focusing on our developments and results.  
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THYCH01 Issues and Challenges for Short Pulse Radiation Production electron, injection, collider, beamloading 225
 
  • P. Emma
    SLAC/ARDA, Menlo Park, California
  A new generation of light sources are being planned at many locations, pushing the frontiers of brightness, wavelength, and peak power well beyond existing 3rd generation sources. In addition to these large scale improvements there is great interest in extremely short duration pulses into the femtosecond and sub-femtosecond regime. Collective electron bunch instabilities at these scales are severe, especially in consideration of the high-brightness electron bunch requirements. Several new schemes propose very short radiation pulses generated with moderate electron bunch lengths. Such schemes include radiation pulse compression, differential bunch spoiling, staged high-gain harmonic generation, and selective pulse seeding schemes. We will describe a few of these ideas and address some of the electron bunch length limitations, highlighting recent measurements at the Sub-Picosecond Pulse Source (SPPS) at SLAC where <100-fs electron and x-ray pulses are now available.  
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THOBCH01 The Beijing Electron-positron Collider and its Second Phase Construction collider, synchrotron, injection, radiation 230
 
  • C. Zhang, J.Q. Wang
    IHEP Beijing, Beijing
  The Beijing Electron-Positron Collider (BEPC) was constructed for both high energy physics and synchrotron radiation researches. As an e+e- collider operating in the tau-charm region and a first synchrotron radiation source in China, the machine has been well operated for 14 years since it was put into operation in 1989. As a collider, the peak luminosity of the BEPC has reached its design goal of 5*1030 cm-2s-1 at J/sai energy of 1.55 GeV and 1*1031 cm-2s-1 at 2 GeV respectively. The main parameters in the dedicated synchrotron radiation operation are: E=2.2~2.5 GeV, ex0=80 mm mrad at 2.2 GeV, Ib=140 mA and the beam lifetime of 20~30 hours. As the second phase project of the BEPC, the BEPCII , has been approved with total budget of 640 million RMB. The construction is started in the beginning of 2004 and is scheduled to complete by the end of 2007. The BEPCII is a double ring machine with its luminosity goal of 1*1033 cm-2s-1 at 1.89 GeV, two orders of magnitude higher than present BEPC. The BEPCII will operate in the beam energy of 1-2.1 GeV so that its physical potential in the whole t and charm range is preserved, while the collider will be optimized at 1.89 GeV. The upgrading of the collider should also provide an improved SR performance with higher beam energy and intensity. The beam currents will be increased to 250 mA at E=2.5 GeV for the dedicated synchrotron radiation operation of the BEPCII. Some key technologies, such as superconducting RF system, low impedance vacuum devices, superconducting micro-beta quadrupoles and etc., has been intensively studied in order to achieve the target of the BEPCII.  
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THOBCH02 DAFNE Operation with the FINUDA Experiment synchrotron, injection, radiation, beamloading 233
 
  • C. Milardi, D. Alesini, G. Benedetti, M.E. Biagini, C. Biscari, 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, L. Pellegrino, M.A. Preger, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, C. Vaccarezza, M. Vescovi, M. Zobov
    INFN/LNF, Frascati (Roma)
  DAFNE operation restarted in September 2003, after a six months shut-down for the installation of FINUDA, a magnetic detector dedicated to the study of hypernuclear Physics. FINUDA is the third experiment running, in sequence, at DAFNE and operates while keeping on place the other detector KLOE. During the shut-down both the Interaction Regions have been equipped with remotely controlled rotating quadrupoles in order to operate at different solenoid fields. Among many other hardware upgrades one of the most significant is the reshaping of the wiggler pole profile to improve the field quality and the machine dynamic aperture. Commissioning of the collider in the new configuration has been completed in short time. The peak luminosity delivered to FINUDA has reached 6 1031 s-1 cm-2, with a daily integrated value exceeding 3 pb-1.

Work presented by C. Milardi on behalf of the DAFNE Team

 
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THOBCH03 Barrier RF Systems in Synchrotrons synchrotron, injection, radiation, beamloading 236
 
  • C.M. Bhat
    Fermilab, Batavia, Illinois
  Recently, the barrier bucket techniques have been used in many interesting applications in proton synchrotrons around the world. Specially designed broad-band rf cavities are used to generate barrier buckets. At Fermilab we have barrier RF systems in four different rings and have used them for various beam gymnastics. Particularly, in the case of Fermilab Recycler Ring, all rf manipulations required during beam cooling, beam stacking and unstacking are carried out using barrier buckets. Also, we have explored new methods for increasing the beam intensities in the Main Injector. Here, I review various uses of barrier rf system in particle accelerators and possible new applications.  
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THZCH01 Status of Tevatron Collider Run II and Novel Technologies for the Tevatron Luminosity Upgrades synchrotron, injection, radiation, beamloading 239
 
  • V.D. Shiltsev
    Fermilab, Batavia, Illinois
  In the Tevatron Run-II, 36 antiproton bunches collide with 36 proton bunches at the CDF and D0 interaction regions at 980 GeV per beam. We present current status and performance of the collider complex. The plan for Run-II luminosity upgrades will be presented and novel technologies for the upgrade will be discussed.  
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THZCH02 Electron Cooling: Remembering and Reflecting synchrotron, injection, radiation, electron 244
 
  • I.N. Meshkov
    JINR, Dubna, Moscow Region
  The report contains a brief review of developments in electron cooling methods. The influence of electron cooling concepts on progress in particle beam physics is considered, particularly: development of alternative and complementary cooling methods - stochastic, laser, muon cooling; physics of cooled and intense particle beams; ordering effects in cooled ion beams and the idea of crystalline beams; intrabeam scattering in cooled beams, etc. Creation of new accelerator technology, based on electron cooling and its application to different fields of experimental physics, particle, nuclear and atomic physics, is described. Modern trends and new concepts of electron cooling applications are discussed.  
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THZCH03 JACoW, a Collaboration Serving the Accelerator Community synchrotron, injection, radiation, electron 249
 
  • J. Poole, C. Petit-Jean-Genaz
    CERN, Geneva
  The Joint Accelerator Conferences Website started from an idea to publish the conference proceedings on the WWW and has grown to an international collaboration which does much more than just publish the proceedings and is currently supported by seven conference series. Through attendance at Steering Committee meetings and Team Meetings and through active participation in the work of the editorial teams of sister conferences, people with the responsibility for the production of the electronic versions of conference proceedings come together to learn from the experience of colleagues, and to develop common approaches to problems. The activities of the collaboration cover all aspects of electronic publication and have recently extended into conference scientific programme management. This paper reviews the history of the collaboration, describes some of the highlights in the activities during the life of the collaboration and presents the current status and future plans.  
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THOALH01 Bunch Length Measurements at the SLS Linac using Electro-optical Techniques laser, synchrotron, injection, electron 253
 
  • A. Winter, M. Tonutti
    RWTH, Aachen
  • S. Casalbuoni, P. Schmüser, S. Simrock, B. Steffen
    DESY, Hamburg
  • T. Korhonen, T. Schilcher, V. Schlott, H. Sigg, D. Suetterlin
    PSI, Villigen
  The temporal profile of the electron bunches in the SLS Linac will be determined by means of electro-optical techniques. A mode locked Ti:Sa Laser with 15 fs pulse width is used for coincidence measurements between the laser pulse and the coherent transition radiation (CTR) generated by short electron bunches. Synchronization accuracy of 100 fs rms between the 3 GHz Linac RF and the 81 MHz repetition rate of the laser was achieved, which is important for the optimum time resolution of the applied electro-optical sampling technique. Likewise, a mode locked Nd:YAG laser with 400 ps long pulses will be used for electro-optical autocorrelation measurements between the CTR and the laser pulses. This alternative technique promises single shot capability and requires much relaxed synchronization stability between laser and electron beam.  
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THOALH02 Development of the Non-invasive Beam-size Monitor using ODR laser, injection, beamloading, beamlosses 256
 
  • T. Muto, S. Araki, H. Hayano, V. Karataev, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  • R. Hamatsu
    TMU, Hatioji-shi,Tokyo
  • A. Naumenko, A.P. Potylitsyn
    Tomsk Polytechnic University, Physical-Technical Department, Tomsk
  The beam-size monitor based on Optical Diffraction Radiation (ODR) has been developed at the KEK-ATF. Because of its non-invasive nature, the ODR monitor might be one candidate to measure the extreme-low emittance electron beam for future LC?s and x-ray free electron lasers. To evaluate the beam-size, the angular distribution of the ODR emitted by the beam when crossing a slit in a metallic foil was measured. In the first trial, we observed interference patterns between ODR and backgrounds which may be the synchrotron radiation from most nearest bending magnet at the ATF extracted line. By the installation of the ceramic mask in front of our target, this interference was vanished. And comparing with the result of ODR measurements, we installed the wire scanner in the same position of our monitor. In this paper, we will present developments of the ODR monitor with some experimental results.  
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THOALH03 The Measurements of the Longitudinal Beam Profile on the Preinjector VEPP-5 laser, injection, beamloading, beamlosses 259
 
  • S. Gurov, P.A. Bak, P.V. Logatchev, V. Pavlov, E. Pyata
    BINP SB RAS, Novosibirsk
  • D. Chernousov
    ICKC, Novosibirsk
  For effective work of preinjector VEPP-5 it is necessary 3 ns bunch with charge 1* 1010 electrons from termogun compress to bunch with 40 ps duration on the positron target. A new streak-camera with RF cavity on the main linac frequency is used. Streak-camera with circle scanning allows see 350 ps single light signal with sub-ps resolution. An additional slow scanning can obtain the trochoidal scanning. Thus one can see with picosecond resolution and with less then 1 psec synchronization the train of ten bunches which are spacing by 350psec. The results of worked streak-camera with RF-cavity for circle scanning are presented.  
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THYLH01 Beam Diagnostics at the VUV-FEL Facility electron, injection, radiation, undulator 262
 
  • J. Feldhaus, D. Noelle
    DESY, Hamburg
  The free electron laser (FEL) at the TESLA Test facility at DESY will be the first FEL user facility for VUV and soft X-ray radiation down to 6 nm wavelength, the commissioning starts in summer 2004. Commissioning as well as stable FEL operation require a combination of different diagnostic tools for measuring both electron and photon beam parameters, including the full phase space distribution of the bunch charge, exact timing with sub-picosecond resolution, electron and photon beam overlap along the undulator, radiation beam position in the user area 50-70 m behind the undulator, intensity and spectral distribution of the radiation pulses and others. Much effort has been put in the development of instrumentation for measuring the longitudinal bunch charge distribution, for controlling the electron beam orbit along the undulator, and for online monitoring the radiation intensity, position and spectral distribution. This contribution gives an overview of the complete electron and photon beam diagnostics of the FEL facility and focuses particularly on the instrumentation which is crucial or specific for the FEL operation.  
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THOBLH02 Ultrafast Compton Scattering X-Ray Source Development at LLNL extraction, injection, radiation, undulator 270
 
  • F.V. Hartemann, S. Anderson, C.P.J. Barty, S.M. Betts, R. Booth, J. Brown, K. Crane, R.R. Cross, D.N. Fittinghoff, D. Gibson, E.P. Hartouni, J. Kuba, G.P. Le Sage, D.R. Slaughter, P.T. Springer, A. Tremaine, A.J. Wootton
    LLNL, Livermore, California
  • J. Rosenzweig
    UCLA, Los Angeles, California
  The LLNL PLEIADES (Picosecond Laser-Electron Inter-Action for the Dynamical Evaluation of Structures) facility is now operating between 30 and 80 keV, and produces > 5 x 106 photons per shot at 10 Hz. This important milestone offers a new opportunity to develop laser-driven, compact, tunable x-ray sources for critical applications such as NIF diagnostics, time-resolved material studies, and advanced biomedical imaging. Initial x-rays were captured with a CCD using a CsI scintillator; the photon energy was measured at approximately 70 keV, and the observed spectral and angular distributions found to agree very well with three-dimensional codes. The electron beam was focused to 30 um rms, at 54 MeV, with 250 pC of charge, a relative energy spread of 0.2%, and a normalized emittance of 10 mm.mrad. Optimization of the x-ray dose is currently underway, with the goal of reaching 107 photons per shot and a peak brightness approaching 1017 photons/mm2/mrad2/s/0.1%bandwidth. High-Z K-edge radiographs have been demonstrated, as well as diffraction using highly-ordered pyrolytic graphite crystals. Nonlinear scattering experiments, using a tightly focused laser spot will also be discussed, as well as plans to develop a source capable of reaching 1% conversion efficiency from the electron beam kinetic energy into x-rays, and ultrafast diffraction experiments.  
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THOBLH03 BESSY II Operated as a Primary Source Standard extraction, injection, undulator, laser 273
 
  • R. Klein, R. Thornagel, G. Ulm
    PTB, Berlin
  The Physikalisch-Technische Bundesanstalt (PTB) is the German National Metrology Institute and responsible for the realization and dissemination of the legal units in Germany. For the realization of the radiometric units in the VUV and X-ray spectral range PTB has been using calculable synchrotron radiation of bending magnets from the BESSY I and BESSY II electron storage rings for more than 20 years. The spectral photon flux of synchrotron radiation can be precisely calculated by Schwinger's theory. Therefore, all the storage ring parameters entering the Schwinger equation have to be measured with low uncertainty which requires a stable and reproducible operation of the storage ring. At BESSY II, PTB has installed all equipment necessary to measure the electron energy, the electron beam current, the effective vertical source size and the magnet induction at the radiation source point as well as all geometrical quantities with low uncertainty. The measurement accuracy for these quantities enables PTB to calculate the spectral photon flux from the visible up to the soft X-ray range with relative uncertainties below 0.4 %. We report on the measurement of the storage ring parameters with low uncertainty.  
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THPKF001 Status of 3 GeV CANDLE Synchrotron Light Facility Project extraction, injection, undulator, laser 2251
 
  • V.M. Tsakanov, M. Aghasyan, G. Amatuni, V.S. Avagyan, A. Grigoryan, B. Grigoryan, M. Ivanyan, V. Jalalyan, D. Kalantaryan, V.G. Khachatryan, E.M. Laziev, Y.L. Martirosyan, R.H. Mikaelyan, S. Minasyan, K.N. Sanosyan, S. Tatikian, S. Tunyan, A. Vardanyan
    CANDLE, Yerevan
  CANDLE- Center for the Advancement of Natural Discoveries using Light Emission – is a 3 GeV third generation synchrotron light facility project in Republic of Armenia. The presentation includes the main considerations that underlie the Conceptual Design Report of the project and the progress made after the last EPAC conference. An overview of machine and beam physics study, the prototype and laboratory development is given.  
 
THPKF002 Linac RF Control System for CANDLE. Design and Simulation extraction, injection, undulator, linac 2254
 
  • A. Vardanyan, G. Amatuni
    CANDLE, Yerevan
  The design and constructional features of the control system for 500 MHz and 3 GHz RF system of CANDLE linac are presented. The linac includes an electron gun that is modulated by 500 MHz generator to produce 1 ns electron bunches, 500 MHz and 3 GHz bunchers, pre-accelerating cavity and the main accelerating section at 3 GHz. An important feature of the presented control system is a high level synchronization of amplitude-phase characteristics of the sub-systems that provide the required energy-space characteristics of the accelerated beam. This puts strict requirements on RF frequency, amplitude and phase stabilization. A digital feedback system has been adopted to provide flexibility in the control algorithms. The main feature is a 9 MHz sampling rate for the cavity signals and digital I/Q detection. The design was performed using the RF analyze tool, based on MATLAB SIMULINK, which allows the simulation and analyzes of the field regulation quality. The simulation results for CANDLE Linac RF system, based on the output parameters of electron beam are given.  
 
THPKF004 The Australian Synchrotron Project - Update extraction, injection, undulator, linac 2257
 
  • A. Jackson
    ASP, Melbourne
  The Australian Synchrotron - a 3rd generation synchrotron light facility based on a 3-GeV electron storage ring - is under construction at a site adjacent to Monash University in the Metropolitan District of Melbourne. Site preparation started in September 2003 and project completion is scheduled for March 2007. In this paper we present an overview of the facility and discuss progress to date in meeting this very agressive schedule.  
 
THPKF005 The Australian Synchrotron Project Storage Ring and Injection System Overview extraction, injection, undulator, linac 2260
 
  • G. LeBlanc, M.J. Boland, Y.E. Tan
    ASP, Melbourne
  This paper describes the Australian Synchrotron storage ring. The storage ring is a 3 GeV machine with 14 cells and a circumference of 216 m. The unit cell is based on a Double Bend Achromat (DBA) structure. The design of the magnet lattice and the results of simulations pertaining to the storage ring performance are presented.  
 
THPKF006 Lifetime Studies in the LNLS Electron Storage Ring extraction, injection, undulator, linac 2263
 
  • N.P. Abreu, N.P. Abreu
    UNICAMP, Campinas, São Paulo
  • P.F. Tavares
    LNLS, Campinas
  In this paper we present a set of measurements performed at the 1.37 GeV electron storage ring of the Brazilian Synchrotron Light Source. We measured the beam lifetime as a function of: current per bunch, gap voltage and position of horizontal and vertical scrapers. Those measurements helped us to determine the contribution of various particle loss mechanisms (Touschek, elastic and inelastic scattering and quantum fluctuations) to the lifetime of the beam. Comparison with theory is also presented as well as an interpretation of each effect.  
 
THPKF007 Canadian Light Source Status and Commissioning Results extraction, undulator, linac, laser 2266
 
  • L. Dallin, R. Berg, J.C. Bergstrom, X. Shen, R.M. Silzer, J.M. Vogt, M.S. de Jong
    CLS, Saskatoon, Saskatchewan
  The storage ring for the Canadian Light Source (CLS) was completed in August 2003. By January 2004, after about shifts of commissioning beam currents of up to 25 mA with 0.7 hr lifetimes were achieved. Injection times for 25 mA are about 4 minutes. Commissioning activities include global orbit correction, measurement of machine parameters and beam-based diagnostices. Features of the CLS are a compact lattice (170 m) for a 2.9 GeV storage ring, high performance magnets and a superconducting RF cavity. By July, when beamlines become operational, currents up to 100 mA with 4 hour lifetimes are expected.  
 
THPKF008 Injection System for the Canadian Light Source injection, extraction, undulator, laser 2269
 
  • R.M. Silzer, R. Berg, J.C. Bergstrom, L. Dallin, X. Shen, J.M. Vogt
    CLS, Saskatoon, Saskatchewan
  The full energy injection system for the Canadian Light Source is made up of a 250 MeV linac, a low energy transfer line, a 2.9 GeV booster synchrotron and a high energy transfer line. The system has routinely provided up to 25 mA peak current in a 132 ns pulse train to the CLS storage ring injection point since September 2003. By January, 2004, injection efficiencies up to 10% have been acheived and stored currents up to 25 mA were accumulated in less than 4 minutes. The injection timing system allows a variety of fill patterns. By July, 2004, injection rates of up to 2 mA per second should be possible providing a fill time of under one minute for a 100 mA stored beam.  
 
THPKF009 Orbit Control for the Canadian Light Source injection, extraction, undulator, laser 2272
 
  • R. Berg, L. Dallin, J.M. Vogt
    CLS, Saskatoon, Saskatchewan
  The orbit control system for the Canadian Light Source storage ring is design to provide both static global orbit correction and active correction up to 100 Hz. The system is made up of 48 button monitors (X and Y), 24 fast correcter magnets (X and Y), and 24 slow correction coils in sextupole magnets (X and Y). To date the system has been use to apply static corrections the to CLS storage ring. While some works remains on the horizontal correction, the vertical orbit has been corrected to an RMS value of less tha 0.75 mm. Future corrections may be augmented by some beam-based magnet re-alignment. The orbit correction system is run on a MATLAB(R) operating system. Singular value decompostion (svd) was used extensively to reduce initial gross mis-alignments.  
 
THPKF011 Vibration Measurements at the Swiss Light Source (SLS) injection, extraction, undulator, laser 2275
 
  • S. Redaelli, R.W. Assmann, W. Coosemans
    CERN, Geneva
  • M. Böge, M. Dehler, L. Rivkin
    PSI, Villigen
  Vibration measurements have been carried out at the Swiss Light Source (SLS) site as part of a collaboration between the Paul Scherrer Institute (PSI) and the European Organization for Nuclear Research (CERN). The vibration level of the SLS floor and of some lattice elements of the SLS ring have been monitored under various experimental conditions. In particular, vibration spectra of lattice quadrupoles have been measured with a circulating beam and compared with the spectra of transverse beam positions, as measured with beam position monitors. This paper summarizes the results.  
 
THPKF012 Operation of the Swiss Light Source: Top-up for Highest Performance injection, extraction, undulator, laser 2278
 
  • A. Lüdeke
    PSI, Villigen
  The Swiss Light Source (SLS) is now in its third year of user operation. Right from the beginning Top-up has been the standard mode of operation. Operation at a fixed beam current makes many applications easier to implement and allows to push several systems to higher performance. It enabled us to reach an excellent orbit stability and reproducibility and it made our users less sensitive to shortened beam lifetimes. We succeeded to satisfy the high demands on the availability of the injector system and our flexible timing system allows for a parallel usage of the Linac for experiments during Top-up operation. The impact of Top-up operation on the overall performance of the SLS is documented in this paper.  
 
THPKF013 Terahertz Diagnostics for the Femtosecond X-ray Source at BESSY injection, undulator, beamloading, lattice 2281
 
  • K. Holldack, S. Khan, R. Mitzner, T. Quast, G. Wustefeld
    BESSY GmbH, Berlin
  A longitudinal electron density modulation caused by femtoslicing in a storage ring is accompanied by a strong broad band coherent THz-light emission between 0.3 and 10 THz at certain synchrotron radiation emitting devices downstream of the interaction region. A technique to use the THz signal for the control of the overlap of laser and electron bunch using fast infrared bolometers is described. A new dedicated THz extraction port at a bending magnet as well as a spectroscopic setup based on a Martin Puplett spectrometer will be commissioned in May 2004 together with the new femtoslicing source at BESSY.

* A. Zholentz, M. Zoloterev, PRL 76/1996, 912** H.-J. Baecker et al., these proceedings

 
 
THPKF014 Status of the BESSY II Femtosecond X-ray Source injection, beamloading, lattice, beamlosses 2284
 
  • S. Khan, H.-J. Baecker, J. Bahrdt, H.A. Duerr, V. Duerr, W. Eberhardt, A. Gaupp, K. Godehusen, K. Holldack, E. Jaeschke, T. Kachel, D. Krämer, R. Mitzner, M. Neeb, W.B. Peatman, T. Quast, G. Reichardt, M.-M. Richter, M. Scheer, O. Schwarzkopf, F. Senf, G. Wustefeld
    BESSY GmbH, Berlin
  • I. Hertel, F. Noack, W. Sandner, I. Will, N. Zhavarnokov
    MBI, Berlin
  At the BESSY II storage ring, work is in progress to produce X-ray pulses with 50 fs (fwhm) duration and tunable energy and polarization by "femtoslicing" [*].This work includes extensive alterations to the storage ring (one new and one modified undulator, both in the same straight section, three additional dipole magnets, a new IR beamline, and nine meters of new vacuum vessels) and to two beamlines (relocation and new optical designs), as well as the installation of a femtosecond Ti:sapphire laser system. Commissioning is planned for May 2004. This paper reviews the principles and technical implementation of the new femtosecond X-ray source, and reports the status of the project.

* A. Zholentz, M. Zoloterev, Phys.Rev.Lett. 76 (1996), 912

 
 
THPKF015 Compressed Electron Bunches for THz-Generation - Operating BESSY II in a Dedicated Low Alpha Mode injection, beamloading, lattice, beamlosses 2287
 
  • G. Wustefeld, J. Feikes, K. Holldack, P. Kuske
    BESSY GmbH, Berlin
  For the first time an electron storage ring was operated during regular user shifts in a dedicated 'low alpha' mode, where electron bunches are compressed to 5 times shorter length for THz [*] and short X-ray pulses experiments. The 1 mm rms-long bunches emit powerfull, coherent THz waves, up to 107 times stronger than incoherent radiation. We report on machine set up and operating experience.

* M. Abo-Bakr et al., Phys. Rev. Lett. 88, 254801 (2002)

 
 
THPKF016 The Metrology Light Source of the Physikalisch-Technische Bundesanstalt in Berlin-Adlershof beamloading, lattice, beamlosses, coupling 2290
 
  • R. Klein, G. Ulm
    PTB, Berlin
  • M. Abo-Bakr, P. Budz, K. Bürkmann, D. Krämer, J. Rahn, G. Wustefeld
    BESSY GmbH, Berlin
  PTB, the German National Metrology Institute, has gained approval for the construction of a low-energy electron storage ring in the close vicinity of BESSY II, where PTB operates a laboratory for X-ray radiometry. The new storage ring, named 'Metrology Light Source MLS' will be dedicated to metrology and technology development in the UV and EUV spectral range and so will fill the gap that is present since the shut down of BESSY I. The MLS is designed in close cooperation with BESSY and is located adjacent to the BESSY II facility. Construction will start 2004 and user operation is scheduled to begin in 2008. The MLS has a circumference of 48 m, injection will be from a 100 MeV microtron. The electrons energy is ramped to an eligible value in the range from 200 MeV to 600 MeV. The MLS will be equipped with all the instrumentation necessary to measure the storage ring parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty, enabling PTB to operate the MLS as a primary source standard. Moreover, provision is taken to operated the MLS in a low alpha mode for the production of coherent synchrotron radiation in the far IR and THz region.  
 
THPKF017 Status of the Synchrotron Light Source DELTA beamloading, lattice, beamlosses, coupling 2293
 
  • D. Schirmer, U. Berges, J. Friedl, A. Gasper, M. Grewe, P. Hartmann, R.G. Heine, H. Huck, G. Schmidt, C. Sternemann, M. Tolan, T. Weis, C. Westphal, K. Wille
    DELTA, Dortmund
  Since 1999, the Dortmunder 1.5 GeV electron storage ring DELTA was continuously extended. The facility serves universities and industries as a source of synchrotron radiation on a regional level. The consolidation of the machine was finally completed in 2002. By now, DELTA, operated for 3000 hours per year, has reached a reliability comparable to other facilities in the world. Large improvements have been made in the installation of the beamlines. At present, two undulator beamlines and several dipole beamlines in the range of soft X-rays are in operation. The 5.3 T superconducting asymmetric wiggler (SAW) serves three beamlines in the hard X-ray regime with circular polarized light. Also the accelerator physics research program has been promoted. The vacuum system was revised during the last year to provide extra space for test sections and additional diagnostics. Substantial progress was achieved by SVD based orbit correction and LOCO based optics modelling as well as detailed CBM studies and a new method for fast tune measurements has been implemented. Future developments for machine improvements, such as DSP-based fast local orbit feedback and a frequent injection mode are in preparation.  
 
THPKF018 Study for a Frequent Injection Mode at Delta with Beam Shutters Open injection, synchrotron, beamloading, lattice 2296
 
  • G. Schmidt, M. Benna, U. Berges, J. Friedl, A. Gasper, M. Grewe, P. Hartmann, R.G. Heine, H. Huck, D. Schirmer, S. Strecker, T. Weis, K. Wille, N. Zebralla
    DELTA, Dortmund
  The Dortmunder Electron Accelerator (DELTA) is a 1.5 GeV synchrotron light source. DELTA is now operated for 3000 h per year including 2000 h beam time for synchrotron radiation use. The maximum beam current is limited by rf power. To increase the average beam current a frequent injection scheme with beam shutters open is discussed for Delta. The peak current is not enlarged but the number of injections is increased to establish a quasi constant beam current. The quasi constant beam current has in addition the advantage of a constant synchrotron radiation heat-load on vacuum chambers and experiments. First tests at Delta have shown the gain in stability of the closed orbit during frequent injection. This article shows the possibility to install a frequent injection mode with beam shutters open during injection at DELTA. The results of measurements and simulations are presented.  
 
THPKF019 PETRA III: A New High Brilliance Synchrotron Radiation Source at DESY injection, synchrotron, emittance, beamloading 2299
 
  • K. Balewski, W. Brefeld, W. Decking, Y.L. Li, G.K. Sahoo, R. Wanzenberg
    DESY, Hamburg
  DESY has decided to rebuild its 2304 m long accelerator PETRA II into a dedicated light source called PETRA III. The reconstruction is planned to start mid of 2007.The new light source will operate at an energy of 6 GeV, a current of 100 mA, a horizontal emittance of 1 nmrad and an emittance coupling of 1%. In the first phase thirteen insertion devices are foreseen. In this paper the principle layout of the machine will be presented. The structure of the new machine combines properties of conventional storage rings and light sources and is therefore quite unconventional. One of the major challenges of the project is to achieve the small emittances. The basic idea is to use so called damping wigglers with a total length of 80 m to reduce the horizontal emittance to the desired level. To obtain and maintain the small emittances imposes tight tolerances on spurious dispersion and orbit quality and stability. These limits will be given and discussed.  
 
THPKF020 Improvements of the Orbit Stability at DORIS III injection, emittance, beamloading, lattice 2302
 
  • F. Brinker, O. Kaul
    DESY, Hamburg
  Running since 1974, the storage ring DORIS experienced a major modification in 1991 to run as a dedicated synchrotron radiation source since 1993. Since then the increasing requirements of the users on beam stability lead to a series of technical and operational measures to improve the beam conditions. The beam pipe has been mechanically isolated from the magnets, the cooling has been improved and this year a new orbit feedback came to operation which uses positron beam position monitors as well as photon monitors in the beam lines to stabilise the different photon beams. The different measures taken are presented.