02 Synchrotron Light Sources and FELs

A05 Synchrotron Radiation Facilities

  
Paper Title Page
THXPA01 Overview of the Status of the Diamond Project 2718
 
  • R.P. Walker
    Diamond, Oxfordshire
  
  The presentation will outline the status of the Diamond project including an overview of the major areas of technical challenge including reference to the physics issues and their impact on design and performance. The majority of the talk will present the status and challenges of first commissioning, outlining the current performance and the challenges in achieving operational status.  
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THXPA02 Overview of the Status of the SOLEIL Project 2723
 
  • J.-M. Filhol, J.C. Besson, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.M. Godefroy, C. Herbeaux, V. Le Roux, P. Lebasque, A. Lestrade, M.-P. Level, A. Loulergue, P. Marchand, J.L. Marlats, A. Nadji, L.S. Nadolski, R. Nagaoka, B. Pottin, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
  
  SOLEIL is a third generation synchrotron radiation source, under construction in France near Paris. The storage ring consists of a 357 m circumference ring, with 16 cells and 24 straight sections, out of which up to 21 will house insertion devices (ID). The optics features a low 3.7 nm.rad emittance at the 2.75 GeV operating energy, so as to provide high brilliance, from the VUV up to the hard x-ray domain. To reach a long lifetime, and beam position stabilities in the micron range, significant attention was paid at each design stage (optics, magnets, beam position monitors, vacuum and RF systems…), including on the design of the building, the construction of which is now complete. This resulted in some unprecedented approaches such as the intensive use of NEG coating vessels, or the development of a dedicated SC RF cavity and of 200 kW solid state RF amplifiers. The injector system (100 MeV Linac) and the 3 Hz full energy booster synchrotron have reached nominal operating conditions by fall 2005, while the ring commissioning should start by April 2006. Innovative ID's were designed and built so as to provide the best possible performances in a wide energy range (5 eV to 50 keV).  
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THPLS001 The Strict Solution of a Radiation Problem in Toroidal Cavity 3260
 
  • T.H. Harutunyan
    YSU, Yerevan
  • E.D. Gazazyan, M.K. Khojoyan
    YerPhI, Yerevan
  
  The radiation of charged particles bunch which is moving along the axes of toroidal cavity cross section is considered. The toroidal cavity has a finite value of the quality factor and is filled with special symmetry inhomogeneous dielectric medium. The problem's solution is based on the complete set of the toroidal cavity's own modes being defined strictly for the mentioned dielectric medium the cavity is filled with. The charged particles bunch exists in the cavity during a finite time period and the charged bunch's arising and vanishing effects are examined and are taken into account as well. The toroidal cavity is considered as a convenient model to investigate the electromagnetic properties of the tokamak system, using the defined modes.  
THPLS002 X-ray and Optical Diagnostic Beamlines at the Australian Synchrotron Storage Ring 3263
 
  • M.J. Boland, R.T. Dowd, G. LeBlanc, M.J. Spencer, Y.E. Tan, A. Walsh
    ASP, Clayton, Victoria
  
  Two diagnostic beamlines have been designed and constructed for the Australian Synchrotron Storage Ring. One diagnostic beamline is a simple x-ray pinhole camera system, with a BESSY II style pinhole array, designed to measure the beam divergence, size and stability. The second diagnostic beamline uses an optical chicane to extract the visible light from the photon beam and transports it to various instruments. The end-station of the optical diagnostic beamline is equipped with a streak camera, a fast ICCD camera, a CCD camera and a fill pattern monitor. The beamline design and some commissioning measurements are presented.  
THPLS003 When Less is More - Construction of the Australian Synchrotron 3266
 
  • D. Morris
    ASP, Clayton, Victoria
  
  The Australian Synchrotron is a 3 GeV facility under construction next to Monash University in Melbourne. The project was launched in January 2003 and is scheduled for completion in March 2007. The funding of Aus$206M (about 125 MEuros) covers all costs associated with the site, building, accelerators and the first nine beamlines. The building contract was placed in July 2003 and completed in February 2005. Installation of the accelerators began in April 2005 and should be complete by May 2006. Commissioning of the injection system began in October 2005, and storage ring commissioning will begin mid-2006, with beamline commissioning beginning January 2007 and facility handover in March 2007. The project is being delivered with a staff of less than 50, which has meant that much of the detailed design work and project management for major systems (e.g., the injection system, RF system, support girders, vacuum vessels and front ends) has been performed by commercial suppliers under turn-key contracts. The presentation will discuss the main technical challenges, and results will be presented of the commissioning of the linac, booster and storage ring.  
THPLS004 Canadian Light Source Update 3269
 
  • L. O. Dallin, M.J. Sigrist, T. Summers
    CLS, Saskatoon, Saskatchewan
  
  The Canadian Light Source (CLS) storage ring has been operating routinely since commissioning was completed in the spring of 2004. Beam currents up to 230 mA have been achieved with the single superconducting RF cavity. With steady improvement beam lifetimes (1/e) of 10 hours at 170 mA and 0.25% coupling are now possible. In the last year the vertical tune was increased by 1 integer to produce a smaller vertical beam size in the ID straight sections. This year the horizontal tune will be increased to reduce the beam emittance. The vertical coupling has been reduced both globally and locally using a skew quadrupole response technique. A wide range of photons energies are provided by an initial complement of five insertion devices (IDs) and and two infrared (IR) ports. The 5 m straights have room for two IDs. The light cones from these IDs are separated by about 1.5 mrad by "chicaning" the electron beam in the straights. To date two IDs have been installed in one straight using the chicaning technique. As well, a superconducting wiggler and a in-vacuum undulator have been installed and commissioned. An AppleII type elliptically polarizing undulator will be installed in April 2006.  
THPLS005 Commissioning Results from the Injection System for the Australian Synchrotron Project 3272
 
  • S. Friis-Nielsen, H. Bach, F. Bødker, A. Elkjaer, N. Hauge, J. Kristensen, L.K. Kruse, S.M. Madsen, S.P. Møller
    Danfysik A/S, Jyllinge
  • M.J. Boland, R.T. Dowd, G. LeBlanc, M.J. Spencer, Y.E. Tan
    ASP, Clayton, Victoria
  • N.H. Hertel, J.S. Nielsen
    ISA, Aarhus
  
  Danfysik has built a full-energy turnkey injection system for the Australian Synchrotron. The system consists of a 100 MeV LINAC, a low-energy transfer beamline, a full-energy booster and a high energy transfer beamline. The booster synchrotron will deliver a 3-GeV beam with an emittance of 33 nm. The lattice is designed to have many cells with combined-function magnets (dipole, quadrupole and sextupole fields) in order to reach this very small emittance. The current in single- and multi-bunch mode will be in excess of 0.5 and 5 mA, respectively. The repetition frequency will be 1 Hz. At the time of writing this abstract, the LINAC beam has been injected into the low-energy transfer beamline. The project is on schedule for delivery in April 2006. Results from the commissioning of the system will be presented together with its performance.  
THPLS006 The Machine Installation at SOLEIL 3275
 
  • J.C. Besson, X. Deletoille, J.-F. Lamarre, D. Lefebvre, H. Rozelot
    SOLEIL, Gif-sur-Yvette
  
  SOLEIL is a third generation Synchrotron radiation Source, under construction in France near Paris. The 357 m circumference storage ring is mainly composed of (32 +1) dipoles, 160 quadrupoles, 120 sextupoles, 2 RF cryomodules, ~ 200 vacuum chambers, 6 injection equipment; 12 beamline front-ends and 4 insertion devices (initially). The 157 m circumference Booster comprises 36 dipoles, 44 quadrupoles, 28 sextupoles, 1 RF cavity and 8 injection/extraction equipment. Before the beginning of the Process installation, a general planning was established detailing the various stages of the equipment installation and their assembly protocols before their on-site installation. In reality, many unknown factors, delays on the buildings, delays on the equipment deliveries, technical problems encountered during the construction, have constrained us to significantly and frequently amend and adapt this initial planning. Due to the various delays, it was also necessary to manage the cohabitation with the various building trades. However, the work made on the initial planning paid off as without its detailed protocols, we could not have carried out the Process installation within correct deadline.  
THPLS007 Magnetic Measurements Results of the Dipoles, Quadrupoles and Sextupoles of the SOLEIL Storage Ring 3278
 
  • P. Brunelle, C. Benabderrahmane, P. Berteaud, F. Briquez, A. Dael, L. Dubois, M. Girault, A. Madur, F. Marteau, A. Nadji, F. Paulin, J. Vétéran
    SOLEIL, Gif-sur-Yvette
  
  During the magnetic measurement campaign, from May 2004 to August 2005, the 326 electro-magnets of the SOLEIL Storage Ring have been characterized in terms of magnetic axis centering and field properties. For the dipoles, two types of measurements have been performed at SOLEIL: field mapping in the mid plan using a Hall probes bench, and field integral comparison with a reference magnet using a stretched wire bench. For the quadrupoles, a rotating coil bench has been built and optimized at SOLEIL in order to reach magnetic center and tilt angle adjustments within ± 25 μm and ± 0.1 mrad respectively. For the sextupoles, magnetic measurements have been performed by the SIGMAPHI Company. This paper will present the main features of the SOLEIL benches, the results of magnetic measurements in terms of reproducibility, field identity between magnets, magnetic axis centering, and harmonic content versus current. Moreover, the origin of some unexpected harmonic field components will be discussed, as well as the magnetic compensation scheme used to minimize some of them.  
THPLS008 Commissioning of the SOLEIL Booster 3281
 
  • A. Loulergue
    SOLEIL, Gif-sur-Yvette
  
  SOLEIL is a 2.75 GeV new third generation synchrotron radiation facility under construction near Paris. The injector system is composed of a 100 MeV electron Linac pre-accelerator followed by a full energy (2.75 GeV) booster synchrotron. The booster lattice is based on a FODO structure with missing magnet. With a circumference of 157 m and low field magnets (0.74 T), the emittance is in the range of 110 to 150 nm.rad at 2.75 GeV. The magnets are excited at 3 Hz, using switched mode power supplies, with digital regulation. The LEP type RF cavity is powered by a 35 kW-352 MHz solid state amplifier. Closed orbits are measured turn by turn, using the BPM Libera digital electronics. The commissioning took place in October 2005, and an acceleration efficiency of 75% was obtained at the maximum energy. The main results achieved during that commissioning will be reported.  
THPLS009 First Results of the Commissioning of SOLEIL Storage Rings 3284
 
  • A. Nadji, J.C. Besson, P. Betinelli, P. Brunelle, A. Buteau, L. Cassinari, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, P. Gros, C. Herbeaux, J.-F. Lamarre, P. Lebasque, M.-P. Level, A. Loulergue, A. Madur, P. Marchand, L.S. Nadolski, R. Nagaoka, B. Pottin, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
  
  The commissioning of SOLEIL's storage ring will start in April 2006. The objective is to reach, within a first phase of two months, stable beam conditions at 100 mA in the multi-bunch mode that can be used for the commissioning of the beamlines. This is a challenging objective, especially because the SOLEIL's ring is incorporating some innovative techniques such as the use of a superconducting RF cavity, NEG coating for all straight parts of the machine and new BPM electronics. Prior to the start of the commissioning, some insertion devices and most of the insertion devices low gap vacuum vessels, including 10 mm inner vertical aperture vessels for the Apple-II type, will be installed on the ring. This paper will review the performances of all these equipment in presence of the beam. The results of the first commissioning runs will be presented.  
THPLS010 Metrology for the Beam Emittance Measurement of the SOLEIL Injector 3287
 
  • M.-A. Tordeux, Y.-M. Abiven, N.L. Leclercq, D. Pedeau
    SOLEIL, Gif-sur-Yvette
  
  The injector system of SOLEIL is composed of a 100 MeV electron linac pre-accelerator followed by a full energy 2.75 GeV booster synchrotron, operating at 3 Hz. Dedicated diagnostics such as emittance monitors are installed on the two transfer lines between the linac and the booster and between the booster and the storage ring. The measurement is performed using the gradient method, relying on YAG screens and high resolution CCD cameras. This paper will show the metrology of the emittance measurements which were made for the HELIOS (THALES) iinac beam (total emittance in the range of 1 μm.rad) and for the booster beam (rms emittance ~ 150 nm.rad): error sources are identified and specific corrections are shown. Additional analysis of the dynamics of the injection into the booster and into the storage ring is made for a deeper characterization.  
THPLS011 Operation and Recent Development at the ESRF 3290
 
  • J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, J. Chavanne, P. Elleaume, L. Farvacque, L. Hardy, J. Jacob, G.A. Naylor, E. Plouviez, A. Ropert, K.B. Scheidt
    ESRF, Grenoble
  
  We report on the achieved performance of the ESRF storage ring as well as developments accomplished or underway. A new hybrid filling mode based on groups of bunches and a 4-bunch filling pattern are now delivered to the users. Following the increasing demand of users for beam stability, the fast orbit feedback has been upgraded. The installation of 5 m-long, 8 mm vertical aperture NEG coated aluminum chambers is progressing at a rate of one chamber per shutdown. The increase in current from 200 to 300 mA is being prepared; however, operation in this mode is still impaired by HOM driven longitudinal instabilities. To overcome this difficulty, a longitudinal feedback is being commissioned. HOM damped cavities are also under study to possibly replace the existing five-cell cavities. The policy of preventive maintenance has been continued. However, in 2005 the machine availability was affected by water leaks occurring on front-end absorbers and on one dipole crotch absorber. The crotch absorbers suffer all from the same erosion process that could be delayed by a systematic vertical realignment, leaving time for procurement and replacement of the entire pool.  
THPLS012 Commissioning of the Australian Synchrotron Injector RF Systems 3293
 
  • C. Piel, K. Dunkel, J. Manolitsas, D. Trompetter, H. Vogel
    ACCEL, Bergisch Gladbach
  • M.J. Boland, R.T. Dowd, G. LeBlanc, M.J. Spencer, Y.E. Tan
    ASP, Clayton, Victoria
  
  On December 16, 2003 the contract for the design, manufacture, installation and commissioning of the turnkey injector system for the Australian Synchrotron Project was awarded to industry. ACCEL Instruments is delivering the turnkey 100MeV linac and the booster RF system. Commissioning of the linac for ASP was performed in December 2005, right after successful commissioning of the Diamond Light Source injection linac*. The 500MHz booster cavity and related low level RF system will be commissioned after installation of the booster is finalised in early 2006. The paper will present design and layout information, as well as commissioning results.

*Commissioning of the Diamond Pre-Injector Linac (this conference).

 
THPLS013 The Magnets of the Metrology Light Source in Berlin-Adlershof 3296
 
  • P. Budz, M. Abo-Bakr, K. Buerkmann-Gehrlein, V. Duerr, J. Kolbe, D. Krämer, J. Rahn, G. Wüstefeld
    BESSY GmbH, Berlin
  • I.N. Churkin, E.R. Rouvinsky, E.P. Semenov, S.V. Sinyatkin, A.G. Steshov
    BINP SB RAS, Novosibirsk
  • R. Klein, G. Ulm
    PTB, Berlin
  
  PTB, the German National Metrology Institute in close cooperation with BESSY II, is currently carrying out the project of constructing the low-energy "Metrology Light Source" (MLS) as a synchrotron radiation facility situated in the close vicinity of BESSY II. Construction of the MLS housing is in progress and nearly finished. The user operation is scheduled to begin in 2008. Dedicated to metrology and technology development in the UV and EUV spectral range, the MLS will bridge the gap that is existent since the shutdown of BESSY I. A 100 MeV microtron delivered by Danfysik A/S will provide the electrons for the MLS with a structure of asymmetric double bend achromat. The total circumference of the MLS is 48 m. The electron energy is ramped to the desired value between 200 MeV and 600 MeV. The MLS magnetic lattice, consisting of 8 bending magnets, 24 quadrupole magnets, 24 sextupole magnets and 4 octupole magnets, is laid out to facilitate this operation. The contract for the MLS magnets is awarded to the Budker Institute for Nuclear Physics. A description of the MLS magnets based on the results of the factory acceptance tests should be presented.  
THPLS014 Status of the Metrology Light Source 3299
 
  • K. Buerkmann-Gehrlein, M. Abo-Bakr, W. Anders, P. Budz, O. Dressler, V. Duerr, J. Feikes, H.G. Hoberg, D. Krämer, P. Kuske, R. Lange, J. Rahn, T. Schneegans, D. Schueler, E. Weihreter, G. Wuestefeld
    BESSY GmbH, Berlin
  • R. Klein, G. Ulm
    PTB, Berlin
  
  For more than 25 years, the Physikalisch-Technische-Bundesanstalt (PTB) uses synchrotron radiation at the storage rings BESSY I and II for photon metrology in the spectral range of UV to x-rays. Since decommissioning of BESSY I (1999), there is a gap in the spectral range of UV and EUV wavelength due to the higher electron energy of BESSY II. Thus, in 2003, the Metrology Light Source (MLS), a low energy electron storage ring, was approved, as central instrument in the future Willy Wien Laboratory (WWL). Design, construction and operation of the MLS are realized by BESSY, based on the PTB requirements for a permanent accessible radiometry source, optimized for the spectral range between UV up to VUV. The MLS is tuneable in energy between 200 MeV and 600 MeV, designed for currents between 1pA up to 200mA. Civil construction of WWL in the close vicinity to BESSY is nearing completion. The first MLS components will be installed in spring 2006, commissioning of the 100MeV Microtron is scheduled for summer 2006, while commissioning of the storage ring will start in spring 2007. Regular user operation will begin in January 2008. A status and an overview on the construction of the MLS are  
THPLS015 Spectral Fingerprints of Femtoslicing in the THz Regime 3302
 
  • K. Holldack, S. Khan, T. Quast
    BESSY GmbH, Berlin
  • R. Mitzner
    Universität Muenster, Physikalisches Institut, Muenster
  
  Femtosecond (fs) THz pulses are observed as a consequence of laser-induced energy modulation of electrons in the BESSY II storage ring in order to generate fs x-ray pulses via femtoslicing*. The THz pulses are spectrally characterized by step-scan and rapid scan FTIR spectroscopy. The temporal shape of the laser-induced density modulation is reconstructed from the THz spectra. It is studied as a function of laser and storage ring parameters and monitored over several revolutions. The results are compared with numerical simulations. The THz spectra acquired over a few seconds are used to optimize the laser parameters for achieving minimum x-ray pulse lengths in femtoslicing experiments.

*A. Zholents and M. Zoloterev, PRL 76 (1996), 912.

 
THPLS016 Bunch Shape Diagnostics Using Femtoslicing 3305
 
  • K. Holldack, T. Quast
    BESSY GmbH, Berlin
  • S. Khan
    Uni HH, Hamburg
  • R. Mitzner
    Universität Muenster, Physikalisches Institut, Muenster
  
  Laser-energy modulation of relativistic electron bunches as needed for the BESSY femtosecond (fs) x-ray source is accompanied by the emission of fs THz pulses*. The total THz intensity probes the square of the longitudinal particle density within a slice of ~50 fs length (fwhm). The bunch shape can be directly monitored while sweeping the time delay between laser and bunch clock. The method is demonstrated for bunch lengths between 3 and 30 ps (rms) in different operation modes of BESSY II. The use of THz signals from successive turns and the influence of periodic bursts of coherent synchrotron radiation, which lock to the laser pulse under certain conditions, are discussed. The method is used for setting up and stabilizing the temporal overlap between a fs-laser and a relativistic electron bunch.

*K. Holldack et al., Phys. Rev. Lett. (2006), accepted Dec. 2005.

 
THPLS017 Orbit Stability in the 'Low Alpha' Optics of the BESSY Light Source 3308
 
  • R. Müller, J. Feikes, P. Kuske, G. Wuestefeld
    BESSY GmbH, Berlin
  
  Running the light source during dedicated shifts in the so-called 'low alpha' mode, BESSY serves two major user groups: THz experiments take advantage of intense, coherent synchrotron radiation (CSR) generated by the short bunches. Time resolved experiments appreciate the very short, high intensity VUV and x-ray pulses in the ps range that help, e.g., prepare the high resolution, low intensity fs-slicing experiments. In the 'low alpha' mode, the sensitivity of the storage ring with respect to energy and horizontal orbit is increased by orders of magnitude while the user experiments require the same beam stability as in 'normal' mode. In this paper an overview of the operational conditions of this specific user mode, the stabilization measures taken, observations and available diagnostic results as well as the achievements and shortcomings of the adapted slow orbit feedback are given.  
THPLS018 FLUKA Calculations of Neutron Spectra at BESSY 3311
 
  • K. Ott
    BESSY GmbH, Berlin
  
  The synchrotron light source BESSY consists of a 50 MeV microtron, a full energy synchrotron and a 1.9 GeV storage ring. The electron losses during injection causes electromagnetic cascades within the stainless steel of the vacuum system and the aluminum chambers of the undulators. The cascade-produced neutrons result from giant resonances, quasi-deuteron fissions and photo-pion productions. The cross sections of the evaporation reactions of neutrons are an order of magnitude higher than the cross sections of the latter two reaction channels. The energy distribution of the giant resonance neutrons has a maximum at about 1 MeV in comparison with 100 - 200 MeV of the high energy neutrons. At electron accelerators outside the shielding wall, half of the neutron dose is often determined by the more penetrating high energy part of the neutron fluence. We used the particle interaction and transport code FLUKA for the calculations of the energy distribution of both the fluence and the dose inside and outside the shielding wall for different realistic scenarios. From the integrated spectra we get the calibration factor to determine the total neutron dose from the measurements directly.  
THPLS019 The Metrology Light Source: an Electron Storage Ring Dedicated to Metrology 3314
 
  • R. Klein, G. Ulm
    PTB, Berlin
  • P. Budz, K. Buerkmann-Gehrlein, J. Rahn, G. Wuestefeld
    BESSY GmbH, Berlin
  
  PTB, the German National Metrology Institute, in close cooperation with BESSY, is currently setting up a low-energy electron storage ring (200 MeV up to 600 MeV electron energy), the Metrology Light Source MLS, which will be dedicated to metrology and technology development in the UV and EUV spectral range which synchrotron radiation. The MLS has been designed by BESSY according to PTB specifications. User operation is scheduled to begin in 2008. Currently, the building, housing the storage ring, is nearly completed, and all major parts of the storage ring and the injection system have been ordered or have already been delivered. 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, calculations show, that the MLS is ideally suited for the production of coherent synchrotron radiation in the far IR and THz region. We give a status update on the construction, the instrumentation for the measurement of the storage ring parameters and calculations for a low-  
THPLS020 Progress Report on PETRA III 3317
 
  • K. Balewski
    DESY, Hamburg
  
  Starting from the middle of 2007, the existing storage ring PETRA II at DESY will be converted into the hard x-ray light source PETRA III. The project was launched in 2002, and in preparation of the conversion a technical design report was published in 2004. Since then detailed design and construction of technical components have begun. Prototypes have been built and tested and the procurement of major parts of the machine components such as magnets and vacuum chambers has started. The project is well underway and in line with the goal of starting the rebuilding in 2007 and the commissioning in 2009. In addition to an overall status report, the development of components and measurement results of prototypes will be presented.  
THPLS021 Dynamic Aperture Studies for PETRA III 3320
 
  • Y.J. Li, K. Balewski, W. Decking
    DESY, Hamburg
  
  PETRA III is a low-emittance storage ring dedicated to synchrotron radiation. For efficient injection in the top-up mode, the dynamic aperture has to be larger than 30 mm-mrad in the horizontal plane. This paper presents the choice of tunes and the optimization of the sextupole configuration. Tracking simulations have been performed, including the non-linear effects of 20 four-meters-long damping wigglers and a representative set of undulators. Misalignment and multipole errors are considered as well, leading to specifications for the magnet design and alignment procedure.  
THPLS022 Radiation Dose Related to ANKA Operation Mode 3323
 
  • I. Birkel, MH. Hagelstein, E. Huttel, A.-S. Müller, P. Wesolowski
    FZK, Karlsruhe
  
  Radiation doses in the ANKA hall are measured by area monitoring and Albedo dosimeters. In August 2004 the machine optics was replaced by a new optics with reduced emittance and higher brightness. Measurements of the beam lifetime and the related radiation doses show a strong correlation between the operation mode of the machine and the dose distribution in the hall.  
THPLS023 Wake Computations for the Beam Positioning Monitors of PETRA III 3326
 
  • A.K. Bandyopadhyay, A. Joestingmeier, A.S. Omar
    Otto-Von-Guericke University, Magdeburg
  • K. Balewski, R. Wanzenberg
    DESY, Hamburg
  
  At DESY it is planned to convert the PETRA ring into a synchrotron radiation facility, called PETRA III, in 2007. For proper design of PETRA III it is very important to estimate the wakes due to various discontinuities along the beam pipe. This article is on the wake computations for the beam positioning monitors (BPMs) in the PETRA III beam pipe. Two computer codes, namely MAFIA and Microwave Studio, were used for the electromagnetic field computations. Convergence tests and the agreement between the results of both softwares were taken as criteria in order to validate the results.  
THPLS024 Controlling the Vertical Emittance Coupling in CAMD 3329
 
  • V.P. Suller
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • M.G. Fedurin, P. Jines, D.J. Launey, T.A. Miller, Y. Wang
    LSU/CAMD, Baton Rouge, Louisiana
  
  The vertical beam size in the CAMD Light Source, as measured with an x-ray pinhole camera, indicates an emittance coupling ratio of 3%. This is consistent with the coupling ratio as measured by the betatron tune split when the coupling resonance is fully engaged. It has been shown that the coupling is mainly produced in the 7T wiggler, which is known to produce non-linear fields. To correct this coupling, it is proposed to install up to four skew quadrupoles. The results of testing a prototype skew quadrupole in the lattice are presented. It is shown that the coupling will be substantially corrected by suitably distributing and powering the four skew quadrupoles.  
THPLS025 Diamond Light Source Vacuum Systems Commissioning Status 3332
 
  • M.P. Cox, B. Boussier, S. Bryan, B.F. Macdonald, H.S. Shiers
    Diamond, Oxfordshire
  
  Diamond Light Source is a new 3 GeV light source currently being commissioned in the UK. The main vacuum systems are a 561.6 m circumference electron storage ring and a 158.4 m circumference booster ring. The storage ring target operating pressure is 1·10-9 mbar with 300 mA of stored beam after 100 A.h of beam conditioning. The booster ring target operating pressure is up to an order of a magnitude higher. Pumping is provided by discrete noble diode ion pumps, supplemented by titanium sublimation pumps and NEG cartridge pumps. Vacuum vessel construction is mainly from 316LN stainless steel. There is no in situ bakeout except for the 24 storage ring straights and the front ends. An ex situ bakeout process is used for the storage ring arcs followed by installation under vacuum. This paper reports results and experience from the construction and commissioning of the diamond vacuum systems.  
THPLS026 Front Ends at Diamond 3335
 
  • J. Strachan, D.G. Clarke
    CCLRC/DL, Daresbury, Warrington, Cheshire
  • H.C. Huang, J. Kay
    Diamond, Oxfordshire
  
  This paper describes the three different types of Front End that have been designed to transmit the intense synchrotron radiation generated by the undulator, multi-pole wiggler and bending magnet sources in the Diamond storage ring to the experiments. The functions of the main components and their location in the layout are described. The Finite Element Analysis that has been carried out to verify the performance under the high heat loads generated by Diamond is also described along with the limits on temperature and stress that have been employed in the design.  
THPLS027 Vibration Measurement at Diamond and the Storage Ring Response 3338
 
  • H.C. Huang, J. Kay
    Diamond, Oxfordshire
  
  Controlling and minimising the sources and transmission of vibration in Synchrotron Light Sources is an important factor in achieving the stability needed to generate the very brightest beams. This paper describes the equipment that has been used at Diamond to measure vibration and reports the results of measurements taken on the accelerator floor and on the girder structures carrying the Storage Ring. A description is given of the intensively piled foundations and a comparison is made between the measured response and the modelled response. The contribution to vibration from water and ventilation services is also discussed.  
THPLS028 Pulsed Magnets and Pulser Units for the Booster and Storage Ring of the Diamond Light Source 3341
 
  • V.C. Kempson, J.A. Dobbing
    Diamond, Oxfordshire
  • C.E. Hansen, N. Hauge, G. Hilleke
    Danfysik A/S, Jyllinge
  
  The Diamond booster and storage ring complex require ten pulsed magnet systems, five for the booster (injection and extraction) and five for the storage ring injection. Each has its own specific design criteria, although commonality of approach has been applied wherever possible. This paper describes the design principles and construction method for the various systems and presents the results of power supply tests and magnetic measurements. Finally, initial experience during the Diamond beam commissioning is discussed.  
THPLS029 Commissioning of the Booster Synchrotron for the Diamond Light Source 3344
 
  • V.C. Kempson, R. Bartolini, C. Christou, J.A. Dobbing, G.M.A. Duller, M.T. Heron, I.P.S. Martin, G. Rehm, J.H. Rowland, B. Singh
    Diamond, Oxfordshire
  
  The Diamond booster is a 158 m circumference, 5 Hz synchrotron which accelerates the 100 MeV electron beam from a linac to 3 GeV for full-energy injection into the Diamond storage ring. The booster has been commissioned in the first few months of 2006, following successful initial 100 MeV trials at the very end of 2005. The injection and ramping process, orbit correction and essential beam physics measurements are discussed as are extraction and beam transport to the storage ring.  
THPLS030 Beam Optic Measurements for the Booster Synchrotron of the Diamond Light Source 3347
 
  • B. Singh, R. Bartolini, C. Christou, V.C. Kempson, I.P.S. Martin
    Diamond, Oxfordshire
  • J.K. Jones
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  
  The booster synchrotron of the Diamond Light Source is a full energy injector ramping from 100 MeV to 3 GeV with a repetition rate of 5 Hz. As part of the booster commissioning, beam optic measurements were performed to characterize the booster performance. Through the use of the beam position monitors, orbit corrections, tune and chromaticity measurements were performed at injection energy and during the ramp. A first comparison with the booster model is also discussed.  
THPLS031 Elettra Top-up Requirements and Design Status 3350
 
  • F. Iazzourene, S. Bassanese, A. Carniel, K. Casarin, R. De Monte, M. Ferianis, F. Giacuzzo, M. Lonza, G. Tromba, A. Vascotto
    ELETTRA, Basovizza, Trieste
  
  Elettra is a 2.5 GeV third generation light source in operation since 1993. To provide more stable beams to the users, we plan to operate in the so-called top-up injection mode. The first step is the substitution of the present 1GeV linac by a 100 MeV pre-injector linac and a fast cycling 2.5 GeV synchrotron booster foreseen to be in operation in 2007*. The present paper will report on the requirements for the top-up operation in terms of radiation safety, diagnostics H/S, timing, modality, etc. and the design status. In particular, a new BPM system, based on the log-ratio detectors, has been successfully commissioned on the present transfer line and linac and is ready to be deployed on the new injector and to be used by the new foreseen shot to shot transfer line booster to storage trajectory feedback system. Furthermore, in order to flatten the storage ring filling, the top-up charge will be integrated where needed. Preliminary measurements on the bunch by bunch measurement methods of the storage ring bunch charge are reported.

*“Elettra New Full Energy Injector Status Report”, these proceedings.

 
THPLS032 ELETTRA New Full Energy Injector High Level Software 3353
 
  • C. Scafuri, F. Iazzourene
    ELETTRA, Basovizza, Trieste
  
  The control system for the new full energy injector* will be entirely based on Tango with an object oriented distributed architecture. The availability of the new and modern software platform led us to design and develop a new high level software framework which allows a model-based accelerator control. The new design is fully object oriented and follows a layered approach. The main layers provide a set of different views or abstractions of the underlying accelerator: field layer, machine layer, and optics layer. The field layer handles all the access and communications with the actual devices of the accelerator, e.g., power supplies, instrumentation, etc. The machine layer handles the machine layout description, functional constraints like the association of a string of magnets with one power supply, and the conversion from actual values acquired from the field into values meaningful to beam dynamics problems. The optics layer performs all the actual calculations concerning the beam like beta functions, damping times, etc. An important characteristic of the new library is the unified management of all the needed calibrations and configurations by means of a relational database.

*“Elettra New Full Energy Injector Status Report”, these proceedings.

 
THPLS033 Elettra New Full Energy Injector Status Report 3356
 
  • M. Svandrlik, S. Bassanese, F.C. Cargnello, A. Carniel, K. Casarin, D. Castronovo, P. Craievich, G. D'Auria, R. De Monte, S. Di Mitri, A. Fabris, R. Fabris, M. Ferianis, A. Gambitta, F. Giacuzzo, M. Giannini, F. Iazzourene, G.L. Loda, M. Lonza, F.M. Mazzolini, D.M. Morelli, G. Pangon, C. Pasotti, G. Penco, L.P. Pivetta, L. Rumiz, C. Scafuri, G. Tromba, A. Vascotto, R. Visintini, D. Zangrando
    ELETTRA, Basovizza, Trieste
  
  The Elettra new full energy injector will be based on a 100 MeV linac pre-injector, a 2.5 GeV booster synchrotron and two new beam transfer lines. It will replace the existing 1.2 GeV linac injector and transfer line. Full funding was finally available in 2005, which allowed to start, or in some cases to re-start, the construction activities. The status of the project will be presented in this paper, in particular the progress of the fabrication of various components, like magnets, power supplies, vacuum chambers; also the status of the construction of the building and technical plants will be given. Results of recent optimization studies will also be outlined. The commissioning of the new injector is scheduled to start in Spring 2007, while the first ELETTRA operation for user's with the new full energy injector is expected for the last quarter of 2007.  
THPLS034 Top-up Operation of SPring-8 Storage Ring with Low Emittance Optics 3359
 
  • H. Tanaka, N. Kumagai, M. Masaki, S. Matsui, H. Ohkuma, T. Ohshima, M. Oishi, J. Schimizu, K. Soutome, S. Takano, M. Takao, H. Takebe, K. Tsumaki, H. Yonehara, T. Yorita, C. Zhang
    JASRI/SPring-8, Hyogo-ken
  
  We have succeeded in providing stable and three-times more brilliant x-ray to users by combining top-up operation with low emittance optics. The optics with the low emittance of 3nmrad was first applied to the user operation in November 2002. Although the low emittance provided the brilliant x-ray, the extremely short beam lifetime much disturbed the precise experiments. Moreover, the aborted electron beam damaged the part of vacuum chamber at the beam injection section. The low emittance operation was thus suspended in October 2003. By improving design of the vacuum chamber and introducing the top-up injection, the problems for the stable operation were resolved, and then the top-up operation with the low emittance optics has been first achieved at SPring-8. This paper illustrates how we achieved this sophisticated operation by explaining the following three essential investigations: (1) reduction of natural emittance for a storage ring with four magnet-free long straight sections, (2) protection of vacuum chamber from aborted electron beam, and (3) consistency to the top-up operation. The obtained performance is also described in the paper.  
THPLS035 Next Generation Light Source Storage Ring at SPring-8 3362
 
  • K. Tsumaki, N. Kumagai
    JASRI/SPring-8, Hyogo-ken
  
  A linac-based XFEL and an ERL are widely accepted as next-generation light sources. But they still have many technologically difficult problems to overcome. In contrast, electron beams in a storage ring are very stable. Thus, we examined the possibility of the storage ring as a next-generation light source. We designed a storage ring with an energy of 6 GeV and a circumference of 1436 m. The ring consists of 24 ten-bend achromat cells and has a natural emittance of 83 pm·rad. The circumference is equal to that of SPring-8 storage ring and the cell length is two times, which enables us to replace the existing storage ring with this new one in the SPring-8 tunnel and use the photon beam-lines without constructing new ones. Particle tracking simulation showed that the horizontal dynamic aperture at the center of a straight section is -3.7 mm and +3.4 mm and that it can be increased to -6.6 mm and +10.0 mm by changing the sextupole strength for chromaticity correction while keeping zero chromaticity. In this paper, we describe the design and the dynamic aperture of the extremely low emittance storage ring at SPring-8.  
THPLS036 Results of the Straight-sections Upgrade of the Photon Factory Storage Ring 3365
 
  • T. Honda, S. Asaoka, W.X. Cheng, K. Haga, K. Harada, Y. Hori, M. Izawa, T. Kasuga, Y. Kobayashi, H. Maezawa, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. Nogami, T. Obina, C.O. Pak, S. Sakanaka, H. Sasaki, Y. Sato, T. Shioya, M. Tadano, T. Takahashi, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto
    KEK, Ibaraki
  
  At the 2.5-GeV ring of the Photon Factory (PF), a large reconstruction of the lattice around the straight sections* has been accomplished in 2005. As a result, four short straight sections of 1.5 m have been newly created, and the lengths of the existing straight sections have been much improved. For example, the length of the longest straight section has been extended to 9 m from 5 m. The optics has been optimized for installing short-period narrow-gap (in-vacuum) undulators at the new straight sections. The reconstruction work on the ring was held from March to September 2005. In the range over two-thirds of the storage ring, all the quadrupole magnets and all the beam ducts have been renewed and rearranged. Commissioning of the storage ring was started from the end of September 2005 and continued for one month. The operation for the user experiment was resumed from the end of October on schedule. Though we made no in-situ baking after the installation for the beam ducts, the vacuum scrubbing by the synchrotron radiation is running very well. The product of the beam lifetime and the beam current exceeded 700 A min for the operation current 450 mA at the end of December 2005.

*S. Asaoka et al. "New Upgrade Project for the Photon Factory Storage Ring", AIP Conf. Proc. 705, p161 (2004).

 
THPLS037 Beam Position and Angular Monitor for Undulator by Using SR Monitor Technique 3368
 
  • T. Mitsuhashi, M. Tadano
    KEK, Ibaraki
  
  We presented a beam position monitor by using SR monitor technique in the last PAC05. In this monitor, a visible SR in far tail of the undulator spectrum is extracted by a water-cooled beryllium mirror. We applied a focusing system to observe a beam position in the undulator through an optical image of beam. We continue further study of this monitor, and this time, we add the afocal system like a Kepler type telescope to measure the angular deviation of the beam. This system converts the angular deviation of optical axis of input ray into position deviation, and we can measure an angular deviation of the beam through its position deviation on the CCD. The results show us this method is applicable to monitor an angular deviation of beam in the undulator independent from position deviation, and gap change of undulator has no effect for the beam position monitoring.  
THPLS039 Upgrade and Current Status of the PF Ring Vacuum System 3371
 
  • Y. Tanimoto, Y. Hori, T. Nogami, T. Uchiyama
    KEK, Ibaraki
  
  The vacuum system for the KEK Photon Factory (PF) was extensively modified in 2005 as part of the PF ring straight-sections upgrade project. This project required replacements of the quad magnets in both northern and southern straight-sections that account for nearly two-thirds of the whole circumference. Therefore, the vacuum ducts in these new quad magnets (Q-ducts), as well as the vacuum ducts in their related bend magnets (B-ducts), needed to be replaced. The new Q-ducts have a narrower cross-section and are equipped with new 4-electrode beam position monitors, and the new B-ducts are furnished with new distributed ion pumps. After the installation of these vacuum chambers, we omitted the thermal in-situ baking, anticipating that beam scrubbing would provide more efficient cleaning. Furthermore, even pre-baking before installation was not performed for the chambers in the northern half in order to evaluate the effect of the pre-baking during the early period of the commissioning. Details of these modifications, as well as the current status of the new vacuum system, will be presented.  
THPLS040 Present Status of the UVSOR-II 3374
 
  • M. Katoh, K. Hayashi, M. Hosaka, A. Mochihashi, J. Yamazaki
    UVSOR, Okazaki
  • T. Hara
    RIKEN Spring-8 Harima, Hyogo
  • M. Shimada
    KEK, Ibaraki
  
  UVSOR electron storage ring, which was a 2nd-generation synchrotron radiation (SR) light source for VUV and soft x-ray region, has been renewed as UVSOR-II at the beginning of 2003. Because of the improvement, the beam emittance has been reduced from 165nm-rad to 27nm-rad, and longer straight sections with smaller vertical betatron functions have been provided. In addition to a helical/linear undulator, two in-vacuum undulators have been installed in the long straight sections at the improvement. New variably polarized undulator will be also installed in summer 2006. Improvement of booster synchrotron will be also performed in summer 2006 with aiming to top-up operation in the future. Now UVSOR-II has been operated in 750MeV with the emittance of 27nm-rad in daily users runs. Not only the development of high quality SR beams but also basic investigations for new light source have been performed; development of storage ring FEL and investigation of intense THz burst SR. Bunch slicing experiment with a Ti:Sa laser (800nm) has also been started since 2005, and experiments for coherent harmonic generation and coherent SR generation with the laser-beam interaction have been performed.  
THPLS041 Observation of Intense Terahertz Synchrotron Radiation produced by Laser Bunch Slicing at UVSOR-II 3377
 
  • M. Katoh, M. Hosaka, K. Kimura, A. Mochihashi, M. Shimada
    UVSOR, Okazaki
  • T. Hara
    RIKEN Spring-8 Harima, Hyogo
  • T. Takahashi
    KURRI, Osaka
  • Y. Takashima
    Nagoya University, Nagoya
  
  We have performed electron bunch slicing experiments using a femto-second high power pulse laser in the UVSOR-II electron storage ring. As the pulse laser system we have used a Ti:Sa laser whose wavelength is 800 nm, typical pulse duration is 100 fs, pulse repetition is 1 kHz and typical average power is 2W. The laser is operated in mode-locked condition and synchronized with the electron beam revolution. The laser pulse is injected into an undulator section and it goes along with the electron bunch. By adjusting the radiation wavelength of the undulator to the laser wavelength, the electron beam energy can be partially modulated in the electron bunch. We have observed THz synchrotron radiation (SR) light from a bending magnet that is downstream of the interaction region. The SR light contains extremely intense THz pulse radiation that is synchronized with the laser injection. The extremely high intensity strongly suggests that the THz pulses are coherent synchrotron radiation from the electron bunch with a hole because of the laser-beam interaction.  
THPLS042 Observation of THz Synchrotron Radiation Burst in UVSOR-II Electron Storage Ring 3380
 
  • A. Mochihashi, M. Hosaka, M. Katoh, K. Kimura, M. Shimada
    UVSOR, Okazaki
  • T. Takahashi
    KURRI, Osaka
  • Y. Takashima
    Nagoya University, Nagoya
  
  Very intense THz synchrotron radiation bursts have been observed in single-bunch operation in the UVSOR-II electron storage ring*. The observation was performed in an infrared beam line in UVSOR-II by using a liquid-He-cooled In-Sb hot-electron bolometer that has a good response time of several microseconds. Thanks both to the beam line and the detector, it is clearly observed that the intense bursts have typical macroscopic and microscopic temporal structure. Macroscopically, it is clearly observed that the bursts tend to be generated with quasi-periodic structure in which the period tends to depend on the beam intensity. From a microscopic point of view, each burst has also quasi-periodic structure in itself, and the period almost corresponds to the half value of the inverse of the synchrotron oscillation frequency. The peak intensity of the bursts was about 10000 times larger than that of ordinary synchrotron radiation in the same wavelength region. The extremely high intensity strongly suggests that the bursts are coherent synchrotron radiation, although the radiation wavelength was much shorter than the electron bunch length.

*Y. Takashima et al., Jpn. J. Appl. Phys. 44, No.35 (2005) L1131.

 
THPLS043 Status of SESAME 3383
 
  • G. Vignola, A. Amro, M. Attal, H. Azizi, A. Kaftoosian, F. Makahleh, M.M. Shehab, H. Tarawneh, S. Varnasseri
    SESAME, Amman
  
  An overview of the status of SESAME is presented. SESAME is a third generation light source facility, with an e-beam energy of 2.5 GeV, located in Allan, Jordan. The emittance is 26 nm.rad and 12 straights are available for insertion devices. The injector consists of a 22.5 MeV microtron and 800 MeV booster synchrotron, with a repetition rate of 1 Hz. The conceptual design of the accelerator complex has been frozen, and the engineering design is in progress. The phase I scientific program for SESAME has also been finalized, and it foresees 6 beam lines, including 2 IR ports. The construction of the SESAME building is in progress, and the beneficial occupancy is expected by the end of 2006. The completion of the accelerators complex construction is scheduled for the end of 2009.  
THPLS044 Preliminary Experiment of the Thomson Scattering X-ray Source at Tsinghua University 3386
 
  • Y.-C. Du, Cheng. Cheng. Cheng, Q. Du, Du.Taibin. Du, W.-H. Huang, Y. Lin, C.-X. Tang, S. Zheng
    TUB, Beijing
  
  A preliminary experiment of the Thomson scattering x-ray source is being planned and constructed to generate short-pulsed, tunable x-rays in the range of ~4.5 kev by Thomson scattering of laser photons from a relativistic electron beam. Laser photons of ? = 1064 nm are Thomson backscattered by a 16MeV electron beam from a 16MeV Backward Travelling Wave (BTW) electron linac. The laser is derived from a 2J,10ns Nd:YAG laser. The parameters of electron beam and laser have been measured. The simulated and experiment results are described in this paper.  
THPLS045 Construction Status of the SSRF Project 3389
 
  • Z. Zhao
    SINR, Jiading, Shanghai
  • H. Ding, H. Xu
    SINAP, Shanghai
  
  The Shanghai Synchrotron Radiation Facility (SSRF), an intermediate energy third generation light source, is under construction at Zhang-Jiang Hi-Tech Park in Shanghai. Its main and auxiliary buildings are scheduled to be completed in October 2006, and this will be followed by the SSRF accelerator installations from October 2006 to March 2008. This paper presents the final design and the current construction status of the SSRF project.  
THPLS046 The Status of Instrumentation and Control for SSRF 3392
 
  • D.K. Liu
    SINAP, Shanghai
  
  The SSRF (Shanghai Synchrotron Radiation Facility) was started in December 25, 2004, and is located in the Zhang Jiang Hi-Teck park in Shanghai. During the past one year, the main structure is under construction and will be completed in the middle of next year on schedule. Various equipment is being processed and tested. The preliminary design of the control system, including various hardware and software, are completed, and some prototype of IOC with EPICS such as LINAC rf station, magnet station and beam diagnosis station, etc. have been already tested successfully. The digital power supply control will be adopted. Various beam instrumentation have been designed for diagnostics of the LINAC, booster and storage ring. The performance of the design, progress of the subsystem and preliminary test results of the prototype will be described in this paper in detail.  
THPLS048 Beam-optics Analysis and Periodicity Restoration in the Storage Ring of the Pohang Light Source 3395
 
  • S.H. Shin, M. Yoon
    POSTECH, Pohang, Kyungbuk
  • E.-S. Kim
    PAL, Pohang, Kyungbuk
  
  The PLS is a third-generation synchrotron radiation source, which provides intense light from ultraviolet to soft x-rays. Similar to other light sources, the PLS is characterized by a small emittance in order to achieve a very high spectral brightness and stably circulating electron beam. To guarantee these characteristics, a thorough understanding of the linear optics has to be carried out, and many storage rings employ LOCO (Linear Optics from Closed Orbits) to analyse the linear optics. This paper will describe the LOCO implementation at PLS and the results.  
THPLS052 The Vacuum System for the Spanish Synchrotron Light Source (ALBA) 3398
 
  • E. Al-Dmour, D. Einfeld, M. Q. Quispe, L. Ribó
    ALBA, Bellaterra
  
  ALBA will be a 3GeV, third generation synchrotron light facility to be built near Barcelona (Spain). The design phase of ALBA is almost completed and the main components have been ordered, which includes the vacuum chambers for the storage ring. Commissioning of the storage ring is foreseen to start at the end of 2008. The circumference of the storage ring of ALBA is 268.8 m, and it will be divided into 16 vacuum sections by ultra high vacuum (UHV) gate valves. The vacuum chamber will be made of stainless steel with an internal vertical aperture of 28 mm and 72 mm width. The vacuum chamber will be connected to an antechamber with a slot of 10 mm height and 20 mm width. The antechamber will have the discrete absorbers, which will absorb the unwanted synchrotron radiation. The pumping will be by sputter ion pumps (SIP) and NEG pumps, with an overall pumping speed from SIP of 57400 l/s. This will maintain an average dynamic pressure of around 1.0·10-9 mbar to achieve a beam lifetime > 15 hours at the designed current. No in-situ bakeout is foreseen, as the vacuum section will be conditioned ex-situ and installed under vacuum to the storage ring.  
THPLS053 Status of the ALBA Project 3401
 
  • D. Einfeld
    ALBA, Bellaterra
  
  ALBA is a 3 GeV light source being built near Barcelona, Spain. ALBA is optimized for high flux density and a large number of available straight sections for insertion devices (3x8 m, 12x4.2 m) in a relatively small circumference of 268.8 m. The light source should be operational in 2010, including the operation of seven beamlines, including six insertion devices. The design of the lattice and of the major components of the accelerator complex (linac and booster, magnets, RF system, vacuum system) is finish and the procurement procedure has started for the large majority of them. The construction of the building will start in the first half of 2006. This report offers an overview of the status of the project, with special emphasis in the new developments.  
THPLS054 Closed Orbit Correction and Beam Dynamics Issues at ALBA 3404
 
  • M. Muñoz, D. Einfeld, T.F. Günzel
    ALBA, Bellaterra
  
  ALBA is a 3 GeV light source being built in Spain. The light source should be operational in 2010.The lattice for the storage ring is now finalized. The basic cells is an extended DBA-like structure with finite dispersion in the straight sections, providing low emittance (under 5nmrad) , small beam cross sections at the source points (less than 150 micro-m horizontal and 10micro-m vertical), and a large number of straight sections (4 times 8m, 12 times 4.2m and 8 times 2.6m). In this paper we review the properties of the lattice with special emphasis in the closed orbit correction system and the lifetime limits.  
THPLS055 Effects of Phase 1 Insertion Devices at the ALBA Project 3407
 
  • M. Belgroune, M. Muñoz
    CELLS, Bellaterra (Cerdanyola del Vallès)
  
  The ALBA new third generation light source offers a large number of straight sections to its community of users. Three types of straights will be available, 4 of 8 m, 12 of 4.2 m and 8 of 2.6 m. The compact lattice of a 268 m circumference ring is now mature and its main components are already fixed. We discuss here the beam dynamics studies performed for Phase 1 Insertion Devices (IDs) where two helical devices HU71, two in-vacuum undulators U21 and a multipole wiggler have been modeled using the kick map approach. This allowed defining the suitable compensation scheme in a machine where the vertical focusing is mainly controlled by the gradients in the dipole magnets. In addition, the Touschek lifetime computations and the identification of the limiting resonances using Frequency Map Analysis showed how strong the working point is in the presence of these IDs. Tolerances on the multipolar components due to the fields' roll-off have also been defined and allowed the progress in the IDs design.  
THPLS056 Synchrotron Radiation Monitors at ALBA 3410
 
  • U. Iriso
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • F. Pérez
    ALBA, Bellaterra
  
  ALBA is a 3 GeV, low emittance third generation synchrotron light source that is in the construction phase in Cerdanyola, Spain. Synchrotron Radiation Monitors (SRM) are one of the most useful, non-destructive tools to easily obtain information of three important parameters for a synchrotron user: beam position, beam dimensions and beam stability. These monitors diagnose beam performance using the radiation produced when the beam traverses a bending magnet. An extensive usage of SRM, based on the visible part of the spectrum, is planned in the ALBA synchrotron: Linac, Booster, Transfer Lines and the Storage Ring. The latter will be equipped as well with an SRM based on the x-ray part of the spectrum, using the PinHole technique in order to accurately measure the low beam size and emittance. This paper describes the different SRM designs for the ALBA light source.  
THPLS057 Injector Design for ALBA 3413
 
  • M. Pont, G. Benedetti, D. Einfeld, A. Falone, U. Iriso, M.L. Lopes, M. Muñoz
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • E. Al-Dmour, F. Pérez
    ALBA, Bellaterra
  • W. Joho
    PSI, Villigen
  
  The storage ring ALBA is a 3rd generation synchrotron light source under construction in Barcelona (Spain). The facility is based on a 3.0 GeV storage ring of 268.8 m circumference with a beam emittance under 5 nm.rad. Top-up operation is foreseen from the start. The injector complex for ALBA will consist of a 100 MeV linac and a full energy booster. The linac will be a turn-key system which has already been ordered to the industry and delivery is expected in the second half of 2007. The full energy booster will be placed in the same tunnel as the storage ring and will have a circumference of 249.6 m. The lattice of the booster is a modified FODO lattice providing an emittance as low as 9 nm.rad. The magnet system comprises 40 combined magnets and 60 quadrupoles. Chromaticity correction relies on the sextupole component built-in the combined magnets and the quadrupoles. In this paper a description of the booster design including the present status of the different components will be given.  
THPLS058 MAX III Commissioning 3416
 
  • M. Eriksson, M. Bergqvist, M. Brandin, L.-J. Lindgren, M. Sjöström, S. Thorin
    MAX-lab, Lund
  
  Some of the features of the 700 MeV MAX III synchrotron radiation storage ring are presented, and the commissioning of this ring is described.  
THPLS059 Status of the MAX IV Light Source Project 3418
 
  • M. Eriksson, M. Berglund, K.I. Blomqvist, M. Brandin, T. Hansen, D. Kumbaro, L.-J. Lindgren, L. Malmgren, M. Sjöström, H. Svensson, H. Tarawneh, S. Thorin, E.J. Wallén, S. Werin
    MAX-lab, Lund
  • B. Anderberg
    AMACC, Uppsala
  
  The present development of the accelerator part of the MAX IV synchrotron radiation project is presented. The main features of the 3 GeV injector linac and the two storage rings operated at different electron energies to cover a broad spectral range of high brilliance undulator radiation are described in some detail. A third ring, the existing MAX III ring, is planned to be transferred to the new facility. The preparation of the injector linac to serve as a free electron laser source and the major sub-systems of the facility are also presented.  
THPLS060 Lifetime and Acceptance at the SLS 3421
 
  • A. Streun, Å. Andersson
    PSI, Villigen
  
  Beam lifetime at the storage ring of the Swiss Light Source (SLS) is limited by Touschek effect and elastic gas scattering. Both mechanism are affected by narrow gaps in the machine, elastic scattering directly by the vertical acceptance limitation, Touschek scattering via a possible restriction of lattice momentum acceptance due to coupling. The particle loss mechanism was explored by evaluations of lifetime as function of scraper position, chromaticity and emittance coupling.  
THPLS061 Status of the Swiss Light Source 3424
 
  • A. Lüdeke, Å. Andersson, M. Böge, B. Kalantari, B. Keil, M. Pedrozzi, T. Schilcher, V. Schlott, A. Streun
    PSI, Villigen
  
  The Swiss Light Source (SLS) is a 3rd generation synchrotron light source in operation since 2001. The paper will point out the recent activities to enhance machine operation and provides an overview about the new beamlines currently under construction at the SLS.  
THPLS062 Sub-picosecond X-ray Source FEMTO at SLS 3427
 
  • A. Streun, A. Al-Adwan, P. Beaud, M. Böge, G. Ingold, S. Johnson, A. Keller, T. Schilcher, V. Schlott, T. Schmidt, L. Schulz, D. Zimoch
    PSI, Villigen
  
  The FEMTO source at the SLS (Swiss Light Source) employs laser/e-beam 'slicing' to produce sub-picosecond x-ray pulses for time resolved pump/probe experiments. The final design of the source, the status of construction and commissioning as well as the first experimental results will be presented.  
THPLS063 Nonlinear Beam Dynamics of TPS 3430
 
  • H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  
  A design study of 3.0 GeV high performance low emittance storage ring Taiwan Photon Source has been conducted recently The natural emittance of the storage ring can be as low as 1.7 nm-rad in our design and its lattice structure is a 24-cell double bend achromat type with circumference of 518.4 m, which will be located in the existing NSRRC site in Hsinchu. The strong focusing requires strong aberration correction with nonlinear sextupole magnets. The distribution of the sextupoles and number of families are studied to ensure a good dynamic aperture. The nonlinear effects in both betatron and synchrotron motions are investigated. Nonlinear beam dynamics effects in the presence of magnetic field imperfections as well as the insertion devices are simulated. The physical aperture limitations are included in the study too, and the Touschek lifetime is calculated. The tracking data are analyzed using frequency map analysis method and corresponding beam dynamics behavior can be revealed more precisely.  
THPLS064 Design Concept of the Vacuum System for the 3 GeV Taiwan Photon Source 3433
 
  • G.-Y. Hsiung, C.K. Chan, C.-H. Chang, H.P. Hsueh, T.L. Yang
    NSRRC, Hsinchu
  • J.-R. Chen
    NTHU, Hsinchu
  
  The design concept of the vacuum system for the electron storage ring of the Taiwan Photon Source (TPS), 518.4 m in circumference, is described. The vacuum system for the synchrotron light source not only meets the specifications of an electron beam energy of 3 GeV and a beam current at 400 mA but also provides a safety factor of 1.7 (~ 500 mA) at 3.3 GeV at the upper bound. The vacuum system for the storage ring is built with consideration of the following features: (1) Large aluminum bending chambers to simplify the ultra-high vacuum (UHV) structure; (2) Absorbers located as far from the source as possible to reduce the heat load and associated yield of photon stimulated desorption (PSD) as well as the photoelectron; (3) Vacuum pumps located in the antechamber and closed to the absorbers to increase the localized pumping efficiency and to minimize the impedance of beam ducts; (4) Quantity of flanges and bellows is significantly reduced. Configuration of the pumps, results of the simulation for the pressure and thermal stress, and the criteria of the design will be discussed.  
THPLS065 Optimization for Taiwan Photon Source Electron Beam Position Monitors through Numerical Simulation 3436
 
  • H.P. Hsueh, C.-H. Chang, G.-Y. Hsiung, C.-K. Kuan, T.-S. Ueng
    NSRRC, Hsinchu
  • J.-R. Chen
    NTHU, Hsinchu
  
  One of the key steps toward successfully building the newly proposed 3rd generation synchrotron radiation research facility, Taiwan Photon Source (TPS), is to optimize the design of the high resolution electron beam position monitors through numerical simulation. With more advanced electromagnetic simulation tool like MAFIA tailored specifically for particle accelerator, the design for the high resolution electron beam position monitors can be tested in such environment before actually fabricated and physically tested. The design goal of our high resolution electron beam position monitors is to achieve 0.1 micron resolution if allowed by engineering limitations. The design consideration to achieve this 0.1 micron resolution goal will also be discussed. The first design has been carried out and the correlated simulations were also carried out with MAFIA. The results are presented and discussed here. Sensitivity as high as 200 has been achieved at 500 MHz. Further study will also be described.  
THPLS066 Improvement on the Single Bunch Operation of the TLS Injector 3439
 
  • J.-Y. Hwang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.H. Hu, S.H. Lee, K.-K. Lin, K.-B. Liu, Y.-C. Liu
    NSRRC, Hsinchu
  
  The improvement of the TLS (Taiwan Light Source) injector on single bunch operation is presented in this study. Limited by the existing design of the TLS injector, the single bunch operation was not optimized in terms of bunch purity for specific users of TLS. A high voltage pulser was implemented to improve the situation. This pulser has been integrated into the high-voltage-deck electronics of electron gun for single bunch generation. Both high-voltage pulses and the associated electron bunches are monitored with a wideband digital oscilloscope. The result shows that the bunch purity can be greatly improved by using the newly installed pulser. It also greatly eliminates the beam losses while injected into the booster ring.  
THPLS067 Vertical Beam Size Control in TLS and TPS 3442
 
  • C.-C. Kuo, H.-P. Chang, J.-R. Chen, P.J. Chou, K.-T. Hsu, G.-H. Luo, H.-J. Tsai, D.-J. Wang, M.-H. Wang
    NSRRC, Hsinchu
  • A. Chao
    SLAC, Menlo Park, California
  • W.-T. Weng
    BNL, Upton, Long Island, New York
  
  Vertical beam size control is an important issue in the light source operations. The horizontal-vertical betatron coupling and vertical dispersion were measured and corrected to small values in the TLS 1.5 GeV storage ring. Estimated beam sizes are compared with the measured values. By employing an effective transverse damping system, the vertical beam blow-up due to transverse coherent instabilities such as the fast-ion beam instability was suppressed and as a result, the light source is very stable. In NSRRC we are designing an ultra low emittance 3-GeV storage ring and its designed vertical beam size could be as small as a few microns. The ground and mechanic vibration effects, and coherent instabilities could spoil the expected photon brightness due to blow-up of the vertical beam size if not well taken care of. The contributions of these effects to vertical beam size increase will be evaluated and the counter measures to minimize them will be proposed and reported in this paper.  
THPLS068 Design of Taiwan Future Synchrotron Light Source 3445
 
  • C.-C. Kuo, H.-P. Chang, C.-T. Chen, P.J. Chou, H.J. Jhao, G.-H. Luo, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  
  We report updated design works for a new 3-3.3 GeV synchrotron light source with a high performance and low emittance storage ring, called Taiwan Photon Source (TPS). With its natural horizontal emittance less than 2 nm-rad and low emittance coupling, TPS will be able to provide an extremely bright photon beam to the demanding users, especially the x-ray community. The lattice type of the TPS is a 24-cell DBA structure and the circumference is 518.4 m. We present the lattice design, the accelerator physics issues and its performances.  
THPLS069 Preliminary Design of the TPS Linac to Booster Transfer Line 3448
 
  • Y.-C. Liu, H.-P. Chang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.-K. Lin, K.-B. Liu, G.-H. Luo
    NSRRC, Hsinchu
  
  The preliminary design of the LTB (linac to booster) transfer line of the proposed TPS (Taiwan Photon Source) project is considered in this study. The layout presented in this report is based on the booster lattice and the choice of linac parameters. These parameters are adopted from previous report of booster design and typical commercial available products of linac. The simulation result indicates that the desired optical functions at a given location can be readily obtained by varying the appropriate focusing strength of quadrupoles. It provides tuning capability to match various possible options of optical functions at injection location. This report is presented together with design consideration of a set of beam diagnostics instruments.  
THPLS073 Effect of Nonlinear Synchrotron Motion on TPS Energy Acceptance 3451
 
  • M.-H. Wang, H.-P. Chang, C.-C. Kuo, G.-H. Luo
    NSRRC, Hsinchu
  
  For design of new generation synchrotron light source the first order momentum compaction factor is usually small. The contribution of second order momentum compaction factor can't be neglected. The longitudinal phase space changes significantly due to the nonlinear effect. This will affect the energy acceptance of the particles and reduce the Touschek beam life time. In this paper we analyze the effect of the nonlinear synchrotron motion of TPS lattice design*. The reduction of energy acceptance is estimated. The contribution to second order momentum compaction factor is discussed. Efforts to minimize this nonlinear effect will also be addressed.

*C. C. Kuo et al., "Design of Taiwan Future Synchrotron Light Source", these proceedings.

 
THPLS074 Ground Vibration Measurement at NSRRC Site 3454
 
  • D.-J. Wang, H.-P. Chang, J.-R. Chen, J.P. Wang, J. Wang
    NSRRC, Hsinchu
  
  For the future 3GeV TPS project in the NSRRC, ground vibration would be important for this low emittance machine. We have monitored the ground vibration under various experimental conditions at the NSRRC site. Sensors were installed in the bare site, underground 35 meters deep and ground of TLS storage ring, including an electricity shutdown in the NSRRC. From the collected data, we compare the effect about day and night, traffic effect, internal machine vibration propagation. Specific vibration sources and their propagations are also discussed.  
THPLS075 Progress in Development of Kharkov X-Ray Generator 3457
 
  • A.Y. Zelinsky, V.P. Androsov, E.V. Bulyak, A. Dovbnya, I.V. Drebot, P. Gladkikh, V.A. Grevtsev, Yu.N. Grigor'ev, A. Gvozd, V.E. Ivashchenko, I.M. Karnaukhov, N. Kovalyova, V.P. Kozin, V. Lapshin, V.P. Lyashchenko, V. Markov, N.I. Mocheshnikov, V.B. Molodkin, A. Mytsykov, I.M. Necklyudov, F.A. Peev, O.V. Ryezayev, A.A. Shcherbakov, A. Shpak, V.L. Skirda, V.A. Skomorokhov, Y.N. Telegin, V.I. Trotsenko, O.D. Zvonarjova
    NSC/KIPT, Kharkov
  • A. Agafonov, A.N. Lebedev
    LPI, Moscow
  • J.I.M. Botman
    TUE, Eindhoven
  • R. Tatchyn
    SLAC, Menlo Park, California
  
  Over the past year the design, development and construction of NSC KIPT X-ray generator NESTOR has been in progress. NESTOR is a new type radiation source on the base of Compton scattering and a 40 - 225 MeV electron storage ring. Electrons are injected in the storage ring at 100 MeV and ramped up to final energy 225 MeV. It is supposed that stored electron beam current will be of about 200 mA. Along with use of Nd:Yag laser of 10 W average power which was developed by High-Q laser firm and optical resonator with accumulation gain of about 1000 it allows to provide X-ray radiation flux up to 1011 phot/s. NESTOR is the cooperative facility and is supported both as well Ukrainian government as NATO SfP project #977982. It is supposed that NESTOR will be in operation in the middle of 2007 year. The status of the project and main facility systems are described in the report.  
THPLS076 Status of RF Deflecting Cavity Design for the Generation of Short X-Ray Pulses in the Advanced Photon Source Storage Ring 3460
 
  • G.J. Waldschmidt, M. Borland, Y.-C. Chae, K.C. Harkay, D. Horan, A. Nassiri
    ANL, Argonne, Illinois
  
  The Advanced Photon Source (APS) at Argonne National Laboratory is exploring the possibility of using radio frequency deflection to generate x-ray radiation pulses on the order of 1 pico-second (Delta t - 70%) or less*. This scheme is based on a proposal by A. Zholents et al.** that relies on manipulating the transverse momenta of the electrons in a bunch by using an rf deflecting cavity to induce a longitudinally dependent vertical deflection of the beam. The beam will then travel through a number of undulators before arriving at a second set of deflecting cavities where the deflection is reversed such that the remainder of the storage ring is largely unperturbed***. Considerable effort has been expended on the design of a superconducting rf deflecting cavity operating in the S-Band at 2.8 GHz to address fundamental design issues including cavity geometry, deflecting voltage, rf power coupling, tuning, and damping of higher-order and lower-order modes. In this paper we present simulation results and analysis of an optimized superconducting rf deflecting cavity design for the APS storage ring.

*K. Harkay et al. Proceedings of 2005 PAC, Knoxville, TN, May 2005, p. 668. **A. Zholents et al. Nucl. Instrum. Methods, A425, 385 (1999). ***M. Borland and V. Sajaev. Proceedings of 2005 PAC, Knoxville, TN, May 2005, p. 3886.

 
THPLS078 Tests of a New Bunch Cleaning Technique for the Advanced Light Source 3463
 
  • F. Sannibale, W. Barry, M.J. Chin
    LBNL, Berkeley, California
  
  A new bunch cleaning technique is being tested at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory. The new procedure allows for high purity, arbitrary filling patterns and is potentially compatible with standard user operation and with the incoming top-off injection mode. The description of the new system and the results of the first tests at the ALS are presented.  
THPLS079 Bunch Diffusion Measurements at the Advanced Light Source 3466
 
  • F. Sannibale, W.E. Byrne, C.-W. Chiu, J. Guo
    LBNL, Berkeley, California
  • J.S. Hull, O.H.W. Siegmund, A.S. Tremsin, J. Vallerga
    UCB, Berkeley, California
  
  In storage ring based synchrotron light sources, a long beam lifetime is usually a fundamental requirement for a high integrated brightness. The dynamic aperture and the momentum acceptance of lattices are carefully studied and maximized as much as possible for a long lifetime performance. On the other hand, large momentum acceptance and dynamic aperture increase the probability that a particle diffuses from one bunch to another. Diffusion can represent a severe limitation for those experiments where the samples have long relaxation times requiring empty buckets between bunches. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory we have characterized the particle diffusion for the present lattice in order to evaluate its impact on a special user operation dedicated to these long relaxation time experiments and on the incoming top-off injection mode for the ALS.  
THPLS082 Status of the Top-off Upgrade of the ALS 3469
 
  • C. Steier, D. Robin, T. Scarvie
    LBNL, Berkeley, California
  
  In order to provide higher brightness and better stability, the ALS is being upgraded to top-off injection. One main part of the top-off modifications is an upgrade of the booster as well as extraction and injection elements and the transfer line for full energy. Further upgrades include new diagnostics, improved controls and timing system, and new radiation safety systems (monitors and interlocks).  
THPLS083 Implementation of the Double-waist Chicane Optics in SPEAR 3 3472
 
  • W.J. Corbett, M. Cornacchia, T. Dao, D. Dell'Orco, D. Harrington, R.O. Hettel, X. Huang, Y. Nosochkov, T. Rabedeau, F.S. Rafael, H. Rarback, A. Ringwall, J.A. Safranek, B. Scott, J.J. Sebek, J. Tanabe, A. Terebilo, C. Wermelskirchen, M. Widmeyer
    SLAC, Menlo Park, California
  • M. Yoon
    POSTECH, Pohang, Kyungbuk
  
  The SPEAR 3 upgrade produced two new 7.6 m racetrack straight sections in the 18 cell, 234 m magnet lattice. One of these straights houses four PEP-II style mode-damped RF cavities. The other straight will accommodate two new small-gap insertion devices separated by 10mrad in a magnetic chicane configuration. A quadrupole triplet has been installed at the midpoint of the chicane and the vertical tune has been raised by an integer to create a 'double waist' optics with betay = 1.6m in the center of each ID. Furthermore, as part of the optics upgrade, betay in the four straights adjacent to the racetrack sections was reduced from 5m to 2.5m. In this paper, we describe the physical implementation of the double-waist chicane optics and initial operational results.  
THPLS085 Nonlinear Dynamics in the SPEAR 3 Double-waist Chicane 3475
 
  • J.A. Safranek, X. Huang, A. Terebilo
    SLAC, Menlo Park, California
  
  A quadrupole triplet has been included in the center of a 7.6 m long chicane in SPEAR 3 to create a novel and technically challenging 'double waist' optics with betay=1.6m at the center of each of two future small-gap insertion devices. The new optics also reduces betay to 2.5m in the four adjacent 4.8m straight sections. In this paper, we discuss key issues associated with design of the machine optics, insertion device compatibility issues, optimization of dynamic aperture and initial measurements of machine performance in the new configuration.  
THPLS087 A Control Theory Approach for Dynamic Aperture 3478
 
  • J. Bengtsson
    BNL, Upton, Long Island, New York
  
  The dynamic aperture problem dates back to the design of the first synchrotrons. Over time, both analytical and numerical methods have been pursued. In the former case mainly by applying techniques developed for celestial mechanics to rather simplified equations of motion. Over the last decade, analysis of the Poincare map has become the method of choice. In particular, application of symplectic integrators, truncated power series algebra, and Lie series techniques has led to a complete set of tools for self-consistent numerical simulations and analytic treatment of realistic models. Nevertheless, a control theory for the general nonlinear case remains elusive. We summarize how to apply this framework to the design of modern synchrotron light sources. Moreover, we also outline how a control theory can be formulated based on the Lie generators for the nonlinear terms.  
THPLS088 Optimizing the Dynamic Aperture for Triple Bend Achromatic Lattices 3481
 
  • S.L. Kramer, J. Bengtsson
    BNL, Upton, Long Island, New York
  
  The Triple Bend Achromatic (TBA) lattice has the potential for lower natural emittance per period than the Double Bend Achromatic (DBA) lattice for high brightness light sources. However, the DBA has been chosen for 3rd generation light sources more often due to the higher number of undulator straight section available for a comparable emittance. The TBA has considerable flexibility in linear optics tuning while maintaining this emittance advantage. We have used the tune and chromaticity flexibility of a TBA lattice to minimize the lowest order nonlinearities using a high order achromatic tune condition, while maintaining a constant emittance. This frees the geometric sextupoles to counter the higher order nonlinearities. This procedure is being used to improve the nonlinear dynamics of the TBA as a proposed lattice for the NSLS-II facility. The flexibility of the TBA lattice will also provide for future upgrade capabilities of the beam parameters.  
THPLS089 Comparison of Double Bend and Triple Bend Achromatic Lattice Structures for NSLS-II 3484
 
  • S.L. Kramer, J. Bengtsson, S. Krinsky
    BNL, Upton, Long Island, New York
  
  The Double Bend Achromatic (DBA) and the Triple Bend Achromatic (TBA) lattice have been studied rather extensively for use for the NSLS-II storage ring. The well known advantage of the TBA compared to the DBA is that the emittance per period has the potential to be considerably lower. However, the DBA has been chosen more often due to the greater number of ID straight sections for the users for a desired emittance. We present a comparison of these lattice structures based on the optimization of the non-linear driving terms from the chromatic sextupole and the ease of compensation of these terms using the higher order achromatic cancellation.  
THPLS090 Consideration of the Double Bend Achromatic Lattice for NSLS-II 3487
 
  • S. Krinsky, J. Bengtsson, S.L. Kramer
    BNL, Upton, Long Island, New York
  
  We present the results of a study of the Double Bend Achromatic (DBA) lattice as a possible choice for the NSLS-II storage ring. The DBA possesses a large number of straight sections with easily tunable beta functions which can be used for insertion device sources and for damping wigglers to reduce emittance. The dispersive regions can be designed to minimize the strength of the chromatic correction sextupoles. A key constraint is the imposition of a limit on circumference which is closely tied to cost. We discuss optimization of the dynamic aperture by minimizing the non-linear driving terms using high-order achromatic cancellation in the non-linear lattice.  
THPLS091 Control of Dynamic Aperture with Insertion Devices 3490
 
  • T.V. Shaftan, J. Bengtsson, S.L. Kramer
    BNL, Upton, Long Island, New York
  
  It is well known that insertion devices (IDs) perturb the linear optics in the vertical plane. In particular, that the effect can be corrected locally by a symmetric arrangement of four quadrupoles on each side of the IDs. We show how to control an arbitrary set of IDs in this configuration with the response matrix for the beta-beat and perturbation of the phase advance and SVD, i.e., to maintain the dynamic aperture. We also evaluate the residual impact on the dynamic aperture from the nonlinear terms and outline how to control these. As an example, we discuss an impact of some ID models on the NSLS-2 dynamic aperture. Results for a single ID and a set of 20 IDs with random field strengths are presented.  
THPLS097 Model of the CSR Induced Bursts in Slicing Experiments 3502
 
  • G.V. Stupakov, S.A. Heifets
    SLAC, Menlo Park, California
  
  In a recent experiment on 'femtoslicing' at the Advanced Light Source in LBNL, it has been observed that the beam slicing initiates correlated bursts of coherent synchrotron radiation (CSR) of the beam. In this paper, we suggest a model describing such bursts. The model is based on the linear theory of the CSR instability in electron rings. We describe how an initial perturbation of the beam generated by the laser pulse evolves in time when the beam is unstable due to the CSR wakefield. Although this model does not give quantitative predictions, it qualitatively explains the evolution of the induced CSR bursts.