Keyword: undulator
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MOYCB101 Brightness and Coherence of Synchrotron Radiation and FELs radiation, brightness, FEL, electron 16
 
  • Z. Huang
    SLAC, Menlo Park, California, USA
  
  Essential properties of radiation from storage rings and FELs include spatial- and temporal beam brightness and coherence. Starting from a fundamental representation of the electron beam as a radiating source the electromagnetic power can be represented as modes in phase-space to characterize beam quality. For storage rings, conditions for transverse coherence are possible which can lead to high-resolution imaging under a variety of polarization conditions. For FELs the radiation brightness is over 10 orders of magnitude higher with finite temporal coherence times and much of the total FEL power contained in the dominant mode. This presentation should provide an overview of the above.  
slides icon Slides MOYCB101 [9.731 MB]  
 
MOZB102 Undulator Technologies for Future Free Electron Laser Facilities and Storage Rings vacuum, radiation, electron, wiggler 26
 
  • M.-E. Couprie
    SOLEIL, Gif-sur-Yvette, France
  
  Insertion devices (undulators and wigglers) are key components for high brightness third generation synchrotron sources and for the amplifying medium of free electron lasers. Different technological developments carried out worldwide lead to improved undulator performance. In particular, the advances concerning the in vacuum permanent magnet systems, in particular for short period ones with the operation at cryogenic temperature with NdFeB or PrFeB magnets or for long period ones where in vacuum wigglers will be described. Secondly, progress in Elliptical Polarised Undulators (EPU) will be discussed, such as the DELTA undulator. Recent progress in superconducting undulators will also be reported. Finally, the effect of the insertion devices on the light source operation is analysed, either with the strategies to compensate unwanted effects or in viewing taking advantage of them as for Robinson or damping wigglers for reducing storage ring horizontal emittance.  
slides icon Slides MOZB102 [8.940 MB]  
 
MOPEA009 ESRF Operation and Upgrade Status storage-ring, emittance, booster, permanent-magnet 82
 
  • J.-L. Revol, J.C. Biasci, J-F. B. Bouteille, F. Ewald, L. Farvacque, A. Franchi, G. Gautier, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, M.L. Langlois, G. Lebec, J.M. Mercier, T.P. Perron, E. Plouviez, P. Raimondi, K.B. Scheidt, V. Serrière
    ESRF, Grenoble, France
  
  The European Synchrotron Radiation Facility (ESRF) is presently midway through the Upgrade Programme Phase I (2009-2015), which concerns its infrastructure, beamlines and X-ray source. This paper reports on the present operation performance of the source, highlighting the more recent developments. In this context, 8 insertion device straight sections have been lengthened from five to six metres; two of them operating with canted undulators. The lattice of one cell has been modified for a further increase to 7 metres allowing the test of a mini beta optics and latter the distribution of cavities. A second cryogenic permanent magnet undulator has been completed, which gives a factor of more than 2 in flux at high energy. The booster klystron-based radio frequency transmitter has been replaced by high power solid state amplifiers. Out of three prototypes of HOM damped cavities working at room temperature which have been received and tested, one has been successfully commissioned with beam. Subsequent to the upgrade of the beam position monitor system, a new orbit feedback has substantially reduced the orbit distortion induced by ID gap motions.  
 
MOPEA028 Present Status of the KEK PF-Ring and PF-AR injection, polarization, photon, linac 136
 
  • K. Tsuchiya, S. Asaoka, K. Haga, K. Harada, T. Honda, Y. Honda, M. Isawa, Y. Kamiya, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, T. Ozaki, H. Sagehashi, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, M. Shimada, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, Y. Tanimoto, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto
    KEK, Ibaraki, Japan
  • H. Takaki
    ISSP/SRL, Chiba, Japan
  
  In KEK, two synchrotron light sources have been operated. One is the 2.5 GeV Photon Factory storage ring (PF-ring) and the other is the 6.5 GeV Photon Factory advanced ring (PF-AR). In this paper, present operational status and recent R&D activities such as fast local bump system for helicity switching undulator, hybrid injection system, pulsed-sextupole injection, etc. Futhermore, upgrade plan towards the top-up injection of 6.5 GeV PF-AR ring is underway. Construction of the straight injection tunnel from linac to PF-AR will be started next fiscal year. Design detail and strategy for the injection scheme will be reported.  
 
MOPEA029 Status of UVSOR III injection, vacuum, sextupole, quadrupole 139
 
  • T. Konomi, M. Adachi, K. Hayashi, M. Katoh, J. Yamazaki
    UVSOR, Okazaki, Japan
  • M. Adachi, M. Katoh
    Sokendai - Okazaki, Okazaki, Aichi, Japan
  
  UVSOR-III is the 750 MeV synchrotron light source. In 2012, three new components were installed in the storage ring. First one is combined function bending magnets to reduce the emittance from 27 nm-rad to 17 nm-rad. These magnets can produce dipole, quadrupole and sextupole fields at the same time. Second ones are an in-vacuum undulator and a beam line. It was installed at 1.5 m straight section, which is the last section reserved for insertion devices. As a result, UVSOR-III is now equipped with six undulators. It would provide soft X-rays to a scanning transmission X-ray microscope (STXM) beam-line. Last one is a newly designed pulse sextupole magnet at the injection point. This is beneficial to the user experiments in the top-up operation mode. Fine machine tuning is in progress.  
 
MOPEA030 Status of UVSOR-III injection, vacuum, cavity, sextupole 142
 
  • N. Yamamoto
    Nagoya University, Nagoya, Japan
  • T. Konomi
    UVSOR, Okazaki, Japan
  
  Construction of the Central Japan Synchrotron Radiation (SR) Facility has been completed in the Aichi area of Japan, and the beam commissioning was started in Spring of 2012. Up to now, it is confirmed that the 1.2 GeV storage ring works with 300 mA Top-up mode. The key equipments of the accelerators are a compact electron storage ring with the ability to supply hard X-rays and full energy injectors for the top-up operation. The accelerators consist of an electron storage ring, a booster synchrotron ring, and an injector linac. In this prezentation, the present status of the accelerators are reported.  
 
MOPEA051 Insertion Devices Influence on the Beam Dynamics at Siberia-2 Storage Ring dynamic-aperture, wiggler, insertion, insertion-device 193
 
  • S.I. Tomin, V. Korchuganov
    NRC, Moscow, Russia
  
  Siberia-2 is now running with 7.5 T wiggler and the installation of additional two 3 T SC wigglers is under consideration. Besides that the insertion of an undulator with very short period up to 7 mm is planed. We studied an influence of the insertion devices on the dynamic aperture using new computer code which permits to find an electron beam trajectory in ID by Runge-Kutta integrator. Using two independent approaches it was shown that ID introduces the nonlinear components of magnetic field which lead to significant decrease of dynamic aperture in vertical direction. Nonlinear components of ID magnetic field are shown. Results of numerical calculation of Siberia-2 dynamic aperture are presented as well.  
 
TUPEA004 The Free-electron Laser FLASH at DESY FEL, photon, gun, linac 1167
 
  • M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch
    DESY, Hamburg, Germany
  
  The free-electron laser FLASH at DESY routinely produces up to several thousand photon pulses per second with wavelengths ranging from 44 nm down to as low as 4.25 nm and with pulse energies of up to 400μJoule. After a significant technical upgrade in 2010, which included an energy upgrade to 1.25 GeV and linearization of the longitudinal phase space by 3-rd harmonic cavities, emphasis was put on consolidation and automatization of operational procedures and better control of the electron/photon beam properties. Some highlights are: on-line measurements of the electron bunch-length in the regime of several 10 fs to 100 fs, reaching into the water window, increased photon pulse energies and the improved machine reproducibility. Moreover, first evidence of HHG seeding was found at the sFLASH experiment in spring 2012. Construction work is ongoing for a 2-nd beam-line (FLASH-2) for which commissioning will start in late 2013.  
 
TUPEA005 Effects of Quantum Diffusion on Electron Trajectories and Spontaneous Synchrotron Radiation Emission electron, radiation, photon, synchrotron 1170
 
  • I.V. Agapov, G. Geloni
    XFEL. EU, Hamburg, Germany
  • O.V. Chubar
    BNL, Upton, Long Island, New York, USA
  
  For various cases, e.g. in the long undulator sections of the European XFEL, quantum diffusion and energy loss have a noticable effect on the electron trajectory, which in turn affects the properties of the emitted radiation. We discuss approaches to modelling the electron dynamics taking this into account and the effect it has on spontaneous radiation emission.  
 
TUPEA006 Towards Realistic Modelling of the FEL Radiation for the European XFEL simulation, radiation, FEL, controls 1173
 
  • I.V. Agapov, G. Geloni
    XFEL. EU, Hamburg, Germany
  
  For the operation phase of the European XFEL the possibility to characterize the FEL radiation taking realistic machine model into account is important. To achieve this, a software framework is being developed. It allows for interoperability of various simulation codes by means of a common graphical user interfaces, common input and output files, and common programming model for scripting; it includes the possibility of modeling beam jitters and machine imperfections to set errorbars on the simulation results, and has a connection to the control system for data acquisition. We report on the progress in the developing of this framework and give examples of FEL property calculations performed with it.  
 
TUPEA007 Spontaneous Radiation Calculations for the European XFEL radiation, electron, emittance, FEL 1176
 
  • I.V. Agapov, G. Geloni
    XFEL. EU, Hamburg, Germany
  • O.V. Chubar
    BNL, Upton, Long Island, New York, USA
  • M. Scheer, M. Titze
    HZB, Berlin, Germany
  • N.V. Smolyakov, S.I. Tomin
    NRC, Moscow, Russia
  
  Calculating spontaneous radiation emission from long undulators such as those present in the European XFEL, being background to FEL radiation, is still important for several diagnostics and science cases. For realistic setups, and including effects of electron beam focusing, emittance and energy spread in the electron beam, these calculations should be performed numerically. We present these calculations for several electron beam and undulator parameters performed by various codes. Sensitivity of different spontaneous radiation characteristics, in various collection schemes, to the electron beam and undulator magnetic field parameters is studied  
 
TUPEA010 FERMI Seeded FEL Progress Report FEL, laser, electron, free-electron-laser 1182
 
  • M. Svandrlik, E. Allaria, F. Bencivenga, C. Callegari, F. Capotondi, D. Castronovo, P. Cinquegrana, P. Craievich, I. Cudin, G. D'Auria, M. Dal Forno, M.B. Danailov, R. De Monte, G. De Ninno, A.A. Demidovich, S. Di Mitri, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, E. Ferrari, P. Finetti, L. Fröhlich, P. Furlan Radivo, G. Gaio, L. Giannessi, M. Kiskinova, G.L. Loda, M. Lonza, B. Mahieu, N. Mahne, C. Masciovecchio, F. Parmigiani, G. Penco, O. Plekan, M. Predonzani, E. Principi, L. Raimondi, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, L. Sturari, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • P. Craievich
    PSI, Villigen PSI, Switzerland
  • B. Mahieu
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  
  Funding: Work supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3
FERMI, the seeded Free Electron Laser located at the Elettra laboratory in Trieste, Italy, welcomed in December 2012 the first external users on the FEL-1 line. This line is based on a single stage of High Gain Harmonic Generation (HGHG), seeded by a UV laser, and covers wavelengths between 80 and 20 nm. The photon energy reached more than 300 μJ. The second FEL line, FEL-2, covering the lower wavelength range between 20 and 4 nm thanks to a double stage cascaded HGHG scheme, has generated its first coherent photons in October 2012. This is the first experimental demonstration of a seeded free electron laser configured as a two stages cascade operating in the "fresh bunch injection” mode, where the second stage is seeded by the light produced by the first stage. This paper describes the status of the operation and user experiments with FEL-1 and reports about the progress in the commissioning of FEL-2. 		 
 
TUPEA011 Double Stage Seeded FEL with Fresh Bunch Injection Technique at FERMI@Elettra FEL, laser, electron, photon 1185
 
  • S. Di Mitri, E. Allaria, D. Castronovo, P. Cinquegrana, P. Craievich, G. D'Auria, M.B. Danailov, G. De Ninno, A.A. Demidovich, B. Diviacco, W.M. Fawley, M. Ferianis, E. Ferrari, L. Fröhlich, G. Gaio, L. Giannessi, R. Ivanov, B. Mahieu, N. Mahne, I. Nikolov, F. Parmigiani, G. Penco, L. Raimondi, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • D. Gauthier
    University of Nova Gorica, Nova Gorica, Slovenia
  
  During the month of October 2012 the commissioning of the light source FEL-2 at FERMI was successfully concluded. Fermi FEL-2 is the first seeded FEL operating with a double stage cascade in the "fresh bunch injection" mode*. The two stages are two high gain harmonic generation FELs where the first stage is seeded by the 3rd harmonic of a Ti:Sa laser system, which is up converted to the 4th-12th harmonic. The output of the first stage is then used to seed the second stage. A final wavelength of 10.8 nm was obtained as the 24th harmonic of the seed wavelength at the end of the two frequency conversion processes, demonstrating that the FEL is capable of producing single mode narrow bandwidth pulses with an energy of several tens ofμjoules. We report on the experimental characterisation of the FEL performances in this configuration.
* I. Ben-Zvi, K. M. Yang, L. H. Yu, ”The ”fresh-bunch” technique in FELs”, NIM A 318 (1992), p 726-729 		 
 
TUPEA013 Present Status of Mid-infrared Free Electron Laser Facility in Kyoto University FEL, gun, electron, cavity 1190
 
  • H. Zen, Y.W. Choi, H. Imon, M. Inukai, T. Kii, R. Kinjo, T. Konstantin, K. Masuda, K. Mishima, H. Negm, H. Ohgaki, K. Okumura, M. Omer, S. Shibata, K. Shimahashi, K. Yoshida
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  
  A Mid-Infrared Free Electron Laser (MIR-FEL) facility named as KU-FEL has been constructed for energy science in Institute of Advanced Energy, Kyoto University*. The accelerator of KU-FEL consists of an S-band 4.5-cell thermionic RF gun, a Dog-leg section for energy filtering, a 3-m traveling-wave type accelerator tube, 180-degree arc section for bunch compression and a hybrid undulator. We have already succeeded in lasing of the FEL from 5.5 to 14.5 micro-meter. Present status and recent activity for the FEL development will be presented in the conference.
*H. Zen, et al., Infrared Physics & Technology, vol.51, 382-385. 		 
 
TUPEA030 High Brightness and Fully Coherent X-ray Pulses from XFELO Seeded High-gain FEL Schemes FEL, radiation, electron, cavity 1214
 
  • H.X. Deng, C. Feng
    SINAP, Shanghai, People's Republic of China
  
  The successful operation of the hard x-ray self-seeding experiment at the LCLS opens the era of fully coherent hard x-ray free electron lasers (FELs). However, the shot-to-shot radiation fluctuation is still a serious issue. In this paper, high-gain, single-pass x-ray FEL schemes seeded by the narrow bandwidth radiation signal from an x-ray FEL oscillator were proposed and investigated, which are expected to generate high brightness, fully coherent and stable x-ray pulse. A simple model has been developed to figure out the temporal and the spectral structures of the output pulses in x-ray FEL oscillator. And options using two synchronized accelerators and using one accelerator were considered, respectively.  
 
TUPEA033 Proposals for Chirped Pulse Amplification in HGHG and CHG at SDUV-FEL FEL, laser, electron, radiation 1217
 
  • C. Feng, L. Shen, D. Wang, D. Xiang, M. Zhang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  
  In this paper, a proposal to generate intense ultra-short free-electron laser (FEL) pulses at Shanghai deep ultraviolet FEL (SDUV-FEL) by combining the chirped pulse amplification (CPA) technique with the high-gain harmonic generation (HGHG) technique is presented. In this proposal, a frequency chirped seed pulse obtained by stretching an ultra-short laser pulse is first used to create frequency-chirped bunching at the laser harmonics in an electron beam; then the frequency chirped harmonic radiation is amplified by an energy chirped electron beam; finally the output radiation pulse which inherits the properties of the seed pulse is compressed to provide an ultra-intense ultra-short radiation pulse. The feasibility and performance of this CPA-HGHG scheme are studied with start-to-end simulations using the parameters of the SDUV-FEL.  
 
TUPEA044 The Design of Control System for the Optical Cavity Adjuster of a FEL-THz Source controls, cavity, FEL, electron 1232
 
  • X. Liu, Q. Fu, B. Qin, P. Tan, C. Wang, Y.Q. Xiong, J. Yang, H. Zeng
    HUST, Wuhan, People's Republic of China
  
  The optical cavity adjuster is an important sub-system in a FEL-THz source, which is used to adjust the position and angle of the optical cavity with a high precision. In view of the requirements of the optical cavity adjuster of the FEL-THz source, this paper presents the design of the control system of the optical cavity adjuster. The design of the control system based on a PC and a motion controller is adopted. The motion controller controls high-precision linear stage to adjust linear direction and picomotors are controlled to enable the adjustment of roll and yaw. According to relevant calculation, the range of linear direction and the accuracy can be reached at ±3mm and 0.2~0.5μm; the range of the adjustment of roll and yaw and the accuracy can be reached at ±2° and 20″. In summing up it can be stated that the design meets the requirements and it also lays the foundation for engineering on developing the optical cavity adjuster.  
 
TUPEA050 Extension of the MAX IV Linac for a Free Electron Laser in the X-ray Region linac, FEL, emittance, electron 1244
 
  • F. Curbis, N. Čutić, M. Eriksson, O. Karlberg, F. Lindau, A. Mak, E. Mansten, S. Thorin, S. Werin
    MAX-lab, Lund, Sweden
  
  The 3 GeV linac for the MAX IV laboratory is currently under construction in Lund (Sweden). As full energy injector for the MAX IV rings, a thermionic gun will be used to create electrons. However a photocathode gun planned for a short pulse facility (SPF) will deliver small emittance and ultra-short electron bunches that will be suitable to also drive a Free-Electron Laser. Moreover extending the linac energy with 1 or 2 GeV will give the opportunity to get closer to 1 Angstrom radiation with much more flexibility and better performances. Given these opportunities at the MAX IV laboratory, a free electron laser is envisaged in the long term perspective of the facility. In this study we investigate the case of a 5 GeV machine which can produce radiation in the X-ray region. The FEL design will benefit from the implementation of self-seeding, to enhance stability of the central wavelength and spectral bandwidth. Tapering along variable gap undulators will help to extract the maximum photon flux and increase the brilliance of the source. Among others, this kind of machine would be suitable for time resolved experiments and imaging.  
 
TUPEA061 High-Brightness SASE Studies for the CLARA FEL FEL, electron, radiation, simulation 1274
 
  • R.N.C. Santer, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  The Compact Linear Accelerator for Research and Applications (CLARA) is a proposed 250 MeV FEL test facility to be constructed at STFC Daresbury Laboratory in the UK [1]. This paper presents study of a scheme for the temporal and spectral stabilisation of the SASE output. A feasibility study for the operation of the FEL in a novel High-Brightness SASE mode is presented. Electron beam delays are introduced between undulator sections to disrupt the localised collective FEL process, increase the radiation coherence length and reduce the rms bandwidth. This may extend the range of electron bunch lengths appropriate for the generation of temporally coherent single spike SASE FEL pulses.  
 
TUPEA085 Optics Tuning and Compensation in LCLS-II quadrupole, focusing, lattice, optics 1313
 
  • Y. Nosochkov, T.O. Raubenheimer, M. Woodley
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the US Department of Energy contract DE-AC02-76SF00515.
The LCLS-II is a future upgrade of the Linear Coherent Light Source (LCLS) at SLAC. It will include two new Free Electron Lasers (FELs) to generate soft and hard X-ray radiation. The 2.9 km LCLS-II lattice will include 1/3 of the SLC linac located just before the existing LCLS, the 1.2 km bypass line, the bend section, the beam separation and diagnostic regions, and the FEL undulators and dump. The LCLS operation showed that occasionally the beam phase space may be significantly mismatched due to various errors in the beamline. This requires correction to ensure good beam quality in the undulators. Similarly, the LCLS-II must have lattice correction system with a large tuning range to cancel such errors. Since the various LCLS-II regions are connected using matching sections, the latter naturally can be used for correction of the mismatched lattice functions. In addition, the large tuning capability is required to provide a wide range of focusing conditions at the FEL undulators. The compensation and tuning abilities of the LCLS-II lattice have been studied for incoming beam errors equivalent to 160% of beta beat and for a factor of 5 in the range of undulator quadrupole strengths. 		 
 
TUPFI081 Progress with Coherent Electron Cooling Proof-Of-Principle Experiment cavity, electron, gun, ion 1535
 
  • I. Pinayev, S.A. Belomestnykh, I. Ben-Zvi, K.A. Brown, J.C. Brutus, L. DeSanto, A. Elizarov, C. Folz, D.M. Gassner, Y. Hao, R.L. Hulsart, Y.C. Jing, D. Kayran, R.F. Lambiase, V. Litvinenko, G.J. Mahler, M. Mapes, W. Meng, R.J. Michnoff, T.A. Miller, M.G. Minty, P. Orfin, A. Pendzick, F. Randazzo, T. Rao, T. Roser, J. Sandberg, B. Sheehy, J. Skaritka, K.S. Smith, L. Snydstrup, R. Than, R.J. Todd, J.E. Tuozzolo, G. Wang, D. Weiss, M. Wilinski, W. Xu, A. Zaltsman
    BNL, Upton, Long Island, New York, USA
  • G.I. Bell, J.R. Cary, K. Paul, B.T. Schwartz, S.D. Webb
    Tech-X, Boulder, Colorado, USA
  • C.H. Boulware, T.L. Grimm, R. Jecks, N. Miller
    Niowave, Inc., Lansing, Michigan, USA
  • M.A. Kholopov, P. Vobly
    BINP SB RAS, Novosibirsk, Russia
  • M. Poelker
    JLAB, Newport News, Virginia, USA
  
  We conduct proof-of-the-principle experiment of coherent electron cooling (CEC), which has a potential to significantly boost luminosity of high-energy, high-intensity hadron colliders. In this paper, we present the progress with experimental equipment including the first tests of the electron gun and the magnetic measurements of the wiggler prototype. We describe current design status as well as near future plans.  
 
TUPME003 Simulations of the ILC Positron Source at Low Energies positron, target, electron, polarization 1562
 
  • A. Ushakov, V.S. Kovalenko, G.A. Moortgat-Pick
    University of Hamburg, Hamburg, Germany
  • S. Riemann, F. Staufenbiel
    DESY Zeuthen, Zeuthen, Germany
  
  Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Optimization", contract number 19XL7Ic4
The International Linear Collider (ILC) baseline design includes an undulator-based positron source. The accelerated electron beam will be used for the positron generation before it goes to the collision point. For the whole ILC energy range the source has to generate 1.5 positrons per electron. However, the efficiency of positron production goes down with decreasing electron drive beam energy. This effect can be compensated to some extend by the choice of undulator parameters and an optimized capture section. The simulation study considers for the range of electron beam energies down to low values of 120 GeV the feasibility to achieve the required positron yield. In particular, the optimum parameters for undulator and capture section are presented depending on the drive electron beam energy. 		 
 
TUPME006 Simulation of Stress in Positron Targets for Future Linear Colliders target, photon, positron, electron 1571
 
  • F. Staufenbiel, S. Riemann
    DESY Zeuthen, Zeuthen, Germany
  • O.S. Adeyemi, V.S. Kovalenko, G.A. Moortgat-Pick, A. Ushakov
    University of Hamburg, Hamburg, Germany
  
  Future linear collider projects require intense positron sources with yields of about 1014 positrons per second. The positron source for the ILC is based on a helical undulator passed by the accelerated electron beam to create an intense circularly polarized photon beam. The positron beam produced by these photons is longitudinally polarized. The intense photon beam causes rapid temperature increase in the target material resulting in periodic stress. The average and peak thermal and mechanical load are simulated. Implications due to long-term target irradiation are considered.  
 
TUPME013 Coherent Thomson Scattering using Beam Echo laser, electron, scattering, radiation 1592
 
  • K. Ohmi, S. Kamada
    KEK, Ibaraki, Japan
  • H. Fares
    Kanazawa University, Kanazawa, Japan
  
  Longitudinal phase space of the beam is modulated by laser interacting in undulators. The beam can have higher frequency component using the beam echo than than the laser as dicussed by G. Stupakov et al. The modulated beam has a potential to emit coherent radiation with the wave length. We evaluate coherent short wave length (~nm) and/or short pulse (attosec) light source using the beam echo in a low energy accelerator ~100MeV.  
 
TUPWA008 Computation of Wakefields for an In-vacuum Undulator at PETRA III vacuum, wakefield, simulation, impedance 1736
 
  • E. Gjonaj, L. Lünzer, T. Weiland
    TEMF, TU Darmstadt, Darmstadt, Germany
  • R. Wanzenberg
    DESY, Hamburg, Germany
  
  Funding: Work supported by DESY, Hamburg, Germany
At DESY the installation of an in-vacuum undulator at the synchrotron radiation facility PETRA III is under consideration. The moveable magnet array of the undulator is installed inside the vacuum chamber to achieve shorter wavelength synchrotron radiation. A thin metal foil covers the magnet structure to mitigate resistive wall wakefields. Moveable tapered transitions connect the magnet structure and the adjacent vacuum duct to reduce the geometric wakefields. Nevertheless these moveable tapered transitions contribute significantly to the impedance budget of PETRA III. The computer codes MAFIA, CST-Studio and PBCI have been used to calculate the longitudinal and transverse wakefields. The results for the loss and kick parameters are presented and compared to the corresponding parameters for a standard undulator section. 		 
 
TUPWO007 Investigation of the Magnetic Chicane of the New Short-Pulse Facility at the DELTA Storage Ring laser, simulation, electron, klystron 1889
 
  • R. Molo, J.A. Grewe, H. Huck, M. Huck, M. Höner, S. Khan, A. Schick, P. Ungelenk
    DELTA, Dortmund, Germany
  
  Funding: Supported by DFG, BMBF, and the Federal State NRW.
The new short-pulse facility at DELTA (a 1.5-GeV synchrotron light source) based on coherent harmonic generation (CHG) utilizes an electromagnetic undulator which can be configured as optical klystron (undulator – chicane – undulator). To optimize the CHG signal, the energy modulation of the electrons in the first undulator and the dispersion of the magnetic chicane (i.e. the R56 matrix element) have to be optimized. Since the R56 value of the present chicane is not sufficient, it is planned to rewire the magnetic coils to create a more efficient chicane. Simulations of the present chicane will be compared to measurements of the R56 matrix element and a new chicane configuration will be presented which increases the R56 value by a factor of ten. 		 
 
TUPWO013 Non-linear Beam Transport Optics for a Laser Wakefield Accelerator radiation, focusing, electron, optics 1907
 
  • C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, N. Braun, B. Härer, P. Peiffer, R. Rossmanith, W. Werner
    KIT, Karlsruhe, Germany
  • O. Jäckel, M. Kaluza, M. Reuter
    HIJ, Jena, Germany
  • M. Kaluza, M. Nicolai, T. Rinck, A. Sävert
    IOQ, Jena, Germany
  • M. Scheer
    HZB, Berlin, Germany
  
  Funding: This work is funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and no. 05K10SJ2
The transport and matching of electron beams generated by a Laser Wakefield Accelerator (LWFA) is a major challenge due to their large energy spread and divergence. The divergence in the range of one milli-radian at energies of some 100 MeV calls for strong focusing magnets. At the same time a chromatic correction of the magnets is needed due to the relative energy spread of a few percent. This contribution discusses in particular the layout of the beam transport optics for a diagnostic beam-line at the LWFA in Jena, Germany. The aim of this optics is to match the betatron functions and the non-zero dispersion to the x-dependent flux density amplitude of a non-planar undulator such that monochromatic undulator radiation is generated despite the large energy spread. The transport line is realized as a dogleg chicane involving several strong focusing quadrupoles. The chromatic error is compensated by additional sextupoles. To keep the setup as compact as possible the magnets are designed as combined function magnets. In this contribution the design and optimization of the transport optics, as well as its realization are presented. 		 
 
TUPWO030 Beam-based Alignment Simulation on Flash-I Undulator quadrupole, simulation, alignment, electron 1940
 
  • D. Gu, Q. Gu, D. Huang, M. Zhang, M.H. Zhao
    SINAP, Shanghai, People's Republic of China
  • M. Vogt, N.J. Walker
    DESY, Hamburg, Germany
  
  In order to ensure the SASE process can take place in the whole FLASH-I undulator section, a straight beam trajectory is mandatory which can only be achieved through beam-based alignment (BBA) method based on electron energy variations. In this paper, a detailed result of simulation is presented which demonstrate that the alignment can be achieved within accuracy of a few 10 μm after several iterations. The influence of Quadrupole and BPM offsets, magnet-mover calibration errors, quadrupole gradient errors are also discussed.  
 
TUPWO035 Physical Design of Beam Transport Line of a Compact Terahertz FEL lattice, quadrupole, electron, FEL 1952
 
  • H. Zeng, Q.S. Chen, Q. Fu, B. Qin, B. Wu, Y.Q. Xiong
    HUST, Wuhan, People's Republic of China
  • G. Feng, Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  The single pass, linac-based compact terahertz source at HUST is now in the physical design stage. To match Twiss parameters and dispersion function of the electron beam at the undulator entrance and get smaller beta function in the whole line, several lattices based on the double bending achromat(DBA) structure were discussed and the optimized design is given with beam dynamics results–calculated by MAD and Trace 3D.  
 
TUPWO057 Active Shimming of Dynamic Multipoles of an APPLE II Undulator in the Diamond Storage Ring polarization, injection, optics, vacuum 1997
 
  • B. Singh, R. Bartolini, R.T. Fielder, E.C. Longhi, I.P.S. Martin, S.P. Mhaskar, R.P. Walker
    Diamond, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  
  Diamond plans to operate a 5 m, long period length, APPLE undulator in a long insertion straight section. Theoretical investigations showed a severe impact on machine dynamics especially when the device is operated in vertical polarization mode. The use of local optics corrections and/or lowering of beta functions were initially investigated as possible solutions but with limited success. Active shimming of dynamic multipoles, following the approach at BESSY-II, proved more effective. The optimum shiming has been devised using kick map approach. In this paper we review the theoretical analysis, the commissioning of the active shims and the undulator, and the net effect of the undulator after compensation.  
 
WEZB101 Status of the European XFEL linac, photon, electron, gun 2058
 
  • M. Hüning
    DESY, Hamburg, Germany
  
  The European XFEL is one of the world's largest accelerators presently under construction. The facility includes a 17.5 GeV superconducting linac with more than 3 km of electron beam transport lines and up to 5 FEL undulators. In mid-2013 the underground civil construction will finish. With most of the large scale production in full swing and first accelerator components installed, this talk should present the XFEL facility status and plans for accelerator commissioning including prospects for first XFEL experiments in Hamburg.  
slides icon Slides WEZB101 [16.980 MB]  
 
WEZB102 Overview of Seeding Methods for FELs FEL, electron, radiation, laser 2063
 
  • S. Reiche
    PSI, Villigen PSI, Switzerland
  
  In recent years enormous progress has been achieved in the theoretical understanding and experimental demonstration of FEL seeding. The state of the art for FEL seeding should be reviewed and compared to HHG, HGHG, EEHG techniques. The potential of various seeding methods and their promise to produce radiation pulses that approach the transform limit in a range of experimental configurations at different user facilities should be explored.  
slides icon Slides WEZB102 [4.238 MB]  
 
WEODB101 X-ray Spectra and Peak Power Control with iSASE FEL, electron, laser, radiation 2068
 
  • J. Wu, F.-J. Decker, Y. Feng, J. Krzywinski, H. Loos, A.A. Lutman, A. Marinelli, H.-D. Nuhn, C. Pellegrini, D.F. Ratner, D.H. Zhang, D. Zhu
    SLAC, Menlo Park, California, USA
  
  Funding: Work is supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515.
We report the first measurement of spectral line-width reduction in a self-amplified spontaneous emission (SASE) X-ray free-electron laser (FEL) obtained by introducing repeated delays of the electron bunch with respect to the radiation field pulse. The improved longitudinal coherence obtained by this method reduces the intensity spiking effect characteristic of a SASE FEL. The electron-photon delays introduced along the FEL undulator mix the spikes phase and amplitude, increasing the cooperation length and generating a smaller bandwidth than in the conventional SASE mode of operation of an FEL. We call this mode of operation, based on repeated electron-photon delays, ‘‘improved SASE'' (iSASE). We also show with theoretical and simulation analysis that in the iSASE mode it is possible to choose the separation and magnitude of the delays to obtain a nearly transform limited X-ray pulse. This analysis is carried out using a time dependent, one-dimensional model and with GENESIS numerical simulation, including three-dimensional effects. 		 
slides icon Slides WEODB101 [7.647 MB]  
 
WEODB102 Generating Polarization Controllable FELs at Dalian Coherent Light Source FEL, polarization, controls, electron 2071
 
  • T. Zhang, H.X. Deng, D. Wang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  • D.X. Dai, G.R. Wu, X.M. Yang, W.Q. Zhang
    DICP, Dalian, People's Republic of China
  
  Funding: 973 Program of China (2011CB808300), NSFC 11175240 and 11205234.
The property of the FEL polarization is of great importance to the user community. FEL pulses with ultra-high intensity and flexible polarization control ability will absolutely open up new scientific realms. In this paper, several polarization control approaches are presented to investigate the great potential on Dalian coherent light source, which is a government-approved novel FEL user facility with the capability of wavelength continuously tunable in the EUV regime of 50-150 nm. The numerical simulations show that both circularly polarized FELs with highly modulating frequency and 100 microjoule level pulse energy could be generated at Dalian coherent light source*.
*T. Zhang, et al., FEL Polarization Control Studies on Dalian Coherent Light Source, Chinese Physics C, 2013, to be published. 		 
slides icon Slides WEODB102 [6.131 MB]  
 
WEODB103 Current Status of PAL-XFEL Project FEL, emittance, gun, klystron 2074
 
  • H.-S. Kang, J.H. Han, T.-H. Kang, C. Kim, D.E. Kim, S.H. Kim, I.S. Ko, H.-S. Lee, K.-H. Park, S.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  The PAL-XFEL is a 0.1-nm hard X-ray FEL construction project which started from 2011 with a total budget of 400 M$. The PAL-XFEL is designed to have three hard X-ray undulator lines at the end of 10-GeV linac and a dog-leg branch line at 3 GeV point for two soft X-ray undulator lines. The three-bunch compressor lattice (3-BC) is chosen to have large flexibility of operation, making it possible to operate soft X-ray FEL undulator line simultaneously and independently from hard X-ray FEL line. Self seeding to achieve the FEL radiation bandwidth of below 5x10-5 is baseline for the hard X-ray FEL line. Polarization control will be available by using the PU + EPU layout for the soft X-ray FEL line. The overview of the project with current status is presented.  
slides icon Slides WEODB103 [8.332 MB]  
 
WEOBB201 Commissioning of the X-band Transverse Deflector for Femtosecond Electron/X-Ray pulse Length Measurements at LCLS FEL, electron, diagnostics, klystron 2091
 
  • Y.T. Ding, C. Behrens, J.C. Frisch, Z. Huang, P. Krejcik, J.R. Lewandowski, H. Loos, J.W. Wang, M.-H. Wang, J.J. Welch
    SLAC, Menlo Park, California, USA
  • C. Behrens
    DESY, Hamburg, Germany
  
  X-ray free-electron lasers provide ultrashort x-ray pulses from several to a few hundred femtoseconds for multidisciplinary users. However, tremendous challenges remain in the measurement and control of these ultrashort pulses with femtosecond precision, for both the electron beam and the x-ray pulses. A new diagnostic scheme adding a transverse radio-frequency deflector at the end of the linac coherent light source (LCLS) undulator beamline has been proposed*. Two 1-m long deflecting structures have been installed at LCLS during the summer of 2012. Installation of the high power RF components including the klystron, waveguide, RF controls etc. is proceeding and commissioning is scheduled for March 2013. We report the latest progress of the commissioning of the deflector at LCLS.
* Y. Ding et al., Phys. Rev. ST Accel. Beams 14, 120701 (2011) 		 
slides icon Slides WEOBB201 [4.199 MB]  
 
WEPWA003 Hall-Probe Bench for Cryogenic in-Vacuum-Undulators vacuum, laser, cryogenics, permanent-magnet 2126
 
  • C. Kuhn, H.-J. Bäcker, J. Bahrdt, A. Gaupp, B. Schulz
    HZB, Berlin, Germany
  
  The Helmholtz-Zentrum Berlin (HZB) builds a 2m long in-vacuum-hall-probe-bench for the characterization of several cryogenic undulators currently under development. Short period lengths and small gaps require an accurate correlation between Hall probe position / orientation and the 3D-magnetic field. The geometric tolerances of an in-vacuum bench in the presence of strong temperature gradients do not permit a Hall probe movement along a straight line without corrections. The HZB-bench employs a system of laser interferometers and position sensitive detectors, which is used in a feed-back loop for the Hall probe position / orientation. First measurements on the accuracy and reproducibility of the new device are presented.  
 
WEPWA005 Experimental Characterization of the Coherent Harmonic Generation Source at the DELTA Storage Ring laser, radiation, electron, synchrotron 2132
 
  • M. Huck, H. Huck, M. Höner, S. Khan, R. Molo, A. Schick, P. Ungelenk
    DELTA, Dortmund, Germany
  • S. Cramm, L. Plucinski, C.M. Schneider
    Forschungszentrum Jülich, Peter-Gruenberg-Institut-6, Jülich, Germany
  • S. Döring, L. Plucinski, C.M. Schneider
    Universität Duisburg-Essen, Duisburg, Germany
  
  Funding: Work supported by DFG, BMBF, and by the Federal State NRW.
The short-pulse facility at the 1.5-GeV synchrotron light source DELTA, operated by the TU Dortmund University, generates coherent VUV and THz radiation by Coherent Harmonic Generation (CHG). Here, a femtosecond laser pulse interacts with an electron bunch in an undulator causing a periodic energy modulation and subsequent micro-bunching, which gives rise to coherent radiation at harmonics of the seed wavelength. Rather than using Ti:Sapphire laser pulses at 795 nm directly, the second harmonic is employed for seeding since 2012. After significant modifications of the seed laser beamline and the dispersive chicane to improve the microbunching, the last commissioning steps include characterization of the CHG radiation and preparing the experimental setup at an existing VUV beamline for time-resolved photoemission spectroscopy. In this paper, the status of the project and recent experimental results are presented. 		 
 
WEPWA007 First Tests with a Local and Integral Magnetic Field Measurement Setup for Conduction Cooled Superconducting Undulator Coils synchrotron, vacuum, radiation, synchrotron-radiation 2138
 
  • A.W. Grau, S. Casalbuoni, S. Gerstl, N. Glamann, T. Holubek, D. Saez de Jauregui
    KIT, Eggenstein-Leopoldshafen, Germany
  
  The magnetic field quality of insertion devices (IDs) has a significant influence on their performance. Therefore it is essential to characterize their magnetic properties and perform precise field measurements before installation in synchrotron light sources. Particularly for permanent magnet IDs the magnetic field measurement technology made significant progress during the last years and pushed the capabilities of synchrotron light sources. Even though for superconducting IDs the measurement settings are far more challenging similar major developments are required. As a part of our R&D program on superconducting IDs we perform quality assessment of their magnetic field properties. This contribution describes details, challenges and the first tests with the measurement equipment configurations to perform measurements of the integral and local magnetic field distributions of superconducting undulator coils up to 2 m length, in a cold (4.2 K), in-vacuum and cryogen free environment.  
 
WEPWA022 The Fabrication and Measurement of the New Insertion Devices of Hefei Light Source vacuum, insertion, insertion-device, radiation 2177
 
  • Q.K. Jia
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more new insertion devices. The new insertion devices include one elliptically polarizing undulator with 104 mm period, one in-vacuum undulator with 40mm period, one wiggler with 152mm period and one quasi-periodic undulator based on a new scheme proposed by us. In this paper the fabrication and the preliminary results of the magnetic field measurements of the new insertion devices are reported.  
 
WEPWA026 Mechanical Design of Shift Driving System for DEPU at SSRF polarization, controls, simulation 2187
 
  • R.B. Deng, W.L. Chen, H.W. Du, Z.B. Yan, M. Zhang
    SINAP, Shanghai, People's Republic of China
  
  Double elliptically polarized undulator (DEPU) for a soft X-ray beamline for ARPES and PEEM is being built at SSRF. In DEPU, two EPUs with different period lengths have the roughly same magnet array lengths and share a common H style frame. The shift driving systems for polarization adjustment, which are set on top of the backing beams for the constraint of space, are sophisticated designed to assure position stability under longitudinal magnet force change. Finite-element analyses are also performed to guarantee the rigidity of the systems. The system performance is tested under full operation range and the results are described in this paper.  
 
WEPWA028 Measurement and Research on Cryogenic Remanence of Chunks Permanent Magnet for Cryogenic Undulator cryogenics, permanent-magnet, controls, factory 2190
 
  • Y.Z. He
    SINAP, Shanghai, People's Republic of China
  
  The higher-precision cryogenic remanence measurment technology and error for chunks permanent magnet were researched in china firstly (10-300K). Magnetic measurement tooling and magnetic field calculation and measurement method of cryogenic remanence measurement system of chunks permanent magnet for cryogenic undulator were optimized. Cryogenic calibration Hall probe were pasted on surface of domestic chunks permanent magnet(Nd2Fe14B: N52, N50M, etc.) and table magnetic field B of permanent magnet were measured, and after being converted, then cryogenic remanence of domestic chunks permanent magnet were obtained and cryogenic remanence variation of domestic chunks permanent magnet were researched. Cryogenic remanence measurement data were checked by pulse B-H tester and PPMS respectively, the results show that cryogenic remanence data has higher reliability. By this experiment, initial foundation were established for development of SSRF cryogenic undulator and for cryogenic remanence measurement and study of domestic other chunks permanent magnets.  
 
WEPWA029 Undulator Chamber R&D for SXFEL vacuum, controls, free-electron-laser, laser 2193
 
  • X. Hu, L. Yin
    SINAP, Shanghai, People's Republic of China
  
  The upcoming construction of Shanghai Soft X-ray Free Electron Laser Facility (SXFEL) will use 18 m small gap undulators. Each undulator is 3 meters long and will work at a minimum gap of 9 mm. This requires a vacuum chamber with an outer height of 8 mm and an elliptic inner aperture. The pressure inside of the chamber shall be less than 10-5 Pa for the beam operation. An oxygen-free copper vacuum chamber was designed and a prototype was developed. This chamber includes three parts, a copper pipe manufactured by stretching, two flanges made of clad metal and a set of supports. The main fabrication procedure and the test results for the chamber prototype are described in this paper.  
 
WEPWA032 The Feed-forward Control Design of Correction Coil Power Supply for SSRF EPU controls, EPICS, power-supply, insertion 2199
 
  • Q. Yuan, M. Gu, G.Y. Jiang, R. Wang
    SINAP, Shanghai, People's Republic of China
  
  The SSRF Elliptically Polarized Undulator (EPU) has been in operation for about three years. The feed-forward control algorithm of correction coil power supply (CCPS) is implemented in the Input and Output Controller (IOC) based on VME. The correction current responds not fast enough to gap movement, mainly because the communication between IOC and digital CCPS taking up much time. This paper introduces one new feed-forward design, that is ,on the one hand, the CCPS current responds to both gap movement and shift movement according to 2D Look-up Table(LUT) by linear interpolation method. On the other hand, feed-forward control algorithm is carried out in the EPU controller, and the CCPS with fast control response is directly controlled by PLC through analog interface. Thus, the correction current respond well to gap and shift movement owing to leaving out communication time.  
 
WEPWA033 The Magnetic Performance of Two Undulators for HLS polarization, multipole, electron, vacuum 2202
 
  • W. Zhang, Q.G. Zhou
    SINAP, Shanghai, People's Republic of China
  • H.F. Wang
    SSRF, Shanghai, People's Republic of China
  
  An elliptically polarized undulator and an in vacuum undulator for HLS have been built at SSRF. The magnetic design of the two Undulators is reviewed. Measurements of the complete undulators are described. Results of performance optimization, including minimization of optical phase error, trajectory wander and integrated multipoles with magic fingers are presented.  
 
WEPWA035 Design of a Superconducting Undulator Magnet Prototype for SSRF superconductivity, synchrotron, electron, storage-ring 2205
 
  • Z.C. Zhang, J. Cui, J.Y. Jiang, M. Li, W. Li, J.P. Xu, J.J. Xu, J.F. Yu
    SINAP, Shanghai, People's Republic of China
  
  Funding: Project 11275254 supported by National Natural Science Foundation of China.
A 0.65 T NbTi superconducting undulator magnet prototype with a period length of 16 mm and a period number of 5 for SSRF is designed. The magnetic field simulation shows that it is possible to obtain a peak field of 0.6 T on the beam axis at a magnetic gap of 9 mm, with a current density of 800A/mm2 in the superconducting coils. Two coil formers are machined from SAE1018 stainless steel and coated with TiO2 for insulation. The dimension of the grooves of the coil windings in the coil formers is 5 mm x 10 mm. Formvar insulated NbTi superconducting wires with a diameter of 0.6 mm are used for the 128 turn coils per core groove. A five periods core of NbTi superconducting magnet is machined from SAE1018 stainless steel and winded with copper wires. 		 
 
WEPWA036 The Magnetic Performance of a Double Elliptically Polarized Undulator polarization, photon, quadrupole, focusing 2208
 
  • Q.G. Zhou, H.F. Wang, M. Zhang, W. Zhang
    SINAP, Shanghai, People's Republic of China
  
  A pair of elliptically polarized undulators with APPLE-II type which will be used in a soft X-ray beam line for ARPES and PEEM at SSRF has been built and installed in the storage ring. The undulators can cover the energy range from 20eV to 2000eV of arbitrary polarized light including the horizontal, vertical, elliptical and circular polarization. The quasi-periodic design of the low energy undulator minimizes the contributions of the higher harmonics to be less than 20%. The magnet design and the measured magnetic field performance will be presented in this paper.  
 
WEPWA038 Influence of Magnet Errors and Waveguide Permeability on Magnetic Field Performance in Pure Permanent Undulators FEL, permanent-magnet, simulation, radiation 2214
 
  • X. Liu, K.F. Liu, B. Qin, P. Tan, B. Wu, Y.Q. Xiong, J. Yang, L. Yang
    HUST, Wuhan, People's Republic of China
  
  Abstract For pure permanent magnet (PM) undulator, unavoidable divergences of remanence field and magnetization vector in PM blocks and installation error will cause magnetic field error at the central line of the undulator. This paper presents the simulation results of the magnetic field in non-ideal undulator containing these errors, with specified tolerances in Normal distribution. As well as the peak field error, increases of the harmonic components and impact on field integrals are calculated. The influence on magnetic field caused by waveguide permeability is also discussed.  
 
WEPWA044 Electron Trajectories in a Three-dimensional Undulator Magnetic Field electron, focusing, radiation, simulation 2223
 
  • N.V. Smolyakov, S.I. Tomin
    NRC, Moscow, Russia
  • G. Geloni
    XFEL. EU, Hamburg, Germany
  
  In this contribution we present an analysis of electron trajectories in the three dimensional magnetic field from a planar undulator. The electron trajectory is influenced by the focusing properties of the undulator field. In the European XFEL case, long segmented undulators (21 segments for the SASE3 beamline to 35 for SASE1 and SASE2) are planned to be installed, with quadrupole lenses between different segments. These focusing properties should be taken into account in simulations of spontaneous radiation, which constitutes the background signal of the FEL. The ideal magnetic field of an undulator can be described by a sinusoidal vertical magnetic field on the undulator axis, and by horizontal and longitudinal field components that appear out of axis. Exploiting this description for the ideal case, an experimentally measured magnetic field is accounted for by solving the differential equations of motion. The electrons' trajectories for the experimentally measured magnetic field were also simulated numerically. To that aim, a computer code was written, which relies on the Runge-Kutta algorithm. The analytical and numerical methods show a good agreement.  
 
WEPWA053 Control System of In-vacuum Undulator in Taiwan Photon Source controls, EPICS, vacuum, insertion 2238
 
  • C.Y. Wu, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, C.Y. Liao
    NSRRC, Hsinchu, Taiwan
  
  Insertion device (ID) is a crucial component in third-generation synchrotron light sources, which can produces highly-brilliant, forward-directed and quasi-monochromatic radiation over a broad energy range for various experiments. In the phase I of the Taiwan Photon Source (TPS) project, seven IU22s (In-Vacuum Undulator) will be planned, constructed, and installed. The control system for IU22 is based on the EPICS architecture. The main control components include the motor with encoder for gap adjustment, trimming power supply for corrector magnets, ion pumpers and BA gauges for vacuum system, temperature sensors for ID environmental monitoring and baking, and interlock system (limit switches, emergency button) for safety. The progress of IU22 control system will be summarized in this report.  
 
WEPWA054 Rejuvenation of Control System of the Undulator 50 in Taiwan Light Source controls, EPICS, insertion, insertion-device 2241
 
  • C.Y. Liao, J. Chen, P.C. Chiu, K.T. Hsu, C.Y. Wu
    NSRRC, Hsinchu, Taiwan
  
  The Undulator 50 (U50) for Taiwan Light Source (TLS) was installed on March 1997 at NSRRC. It provides service for more than 15 years. Control system of U50 includes a PC running MS-DOS for local control. Motion controller contains two indexers with driver via RS-232 interface. It equip with IEEE-488 interface to connect to the VME system for remote access. The response time for command and reply is in the order of second, thus the throughput of the experiment for energy scan is time-consuming. New U50 control system will share the standard environment for insertion devices (ID) control for the Taiwan Photon Source (TPS) project. Ethernet based motion controller was chosen to drive motor drivers. All control functionality will coordinate by the cPCI EPICS IOC. To compatible with TLS existed control environment, a server program was develop to translate the protocol to EPICS PVs. All existed GUI of TLS still can be used. These improvements of control system for U50 are essential upgrading geared to avoid obsolescence of the control related parts, increase productivity and support on-the-fly experiments. The progress of the controls plan will be summarized in this report.  
 
WEPWA055 Multipole and End-field Shimming Results of EPU46 at the TPS multipole, quadrupole, polarization, electron 2244
 
  • T.Y. Chung, C.-H. Chang, J. Chen, J.C. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin
    NSRRC, Hsinchu, Taiwan
  
  Multipole error and the first and second integrals of EPU46 require shimming to fulfill the tolerance requirements of beam dynamics. In this paper, we describe the field correction, including central-field and end-field shimming procedures, and the results for EPU46 at TPS. End-pole shimming for the first and second integrals serve to adjust the beam trajectory, and magic fingers to decrease the multipole error. For the active multipole shimming for undulators of type Apple II, a trim-long-coil array is used to compensate for multipole error. This scheme efficiently eliminates a phase-dependent skew quadrupole error.  
 
WEPWA062 Status of the UK Superconducting Planar Undulator Project cryogenics, vacuum, wakefield, radiation 2259
 
  • J.A. Clarke, B.J.A. Shepherd
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • V. Bayliss, T.W. Bradshaw, S.A. Brown, A.J. Brummitt, G.W. Burton, S.J. Canfer, B. Green, S.R. Watson
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • S.E. Hughes, E.C. Longhi, J.C. Schouten
    Diamond, Oxfordshire, United Kingdom
  
  The UK is developing a short period, narrow aperture, planar superconducting undulator that is planned to be installed and tested in the 3 GeV Diamond Light Source in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. First measurements will be presented of a 19 period test module and also the commissioning of the 2K cryogenic turret.  
 
WEPWA070 Design of a Collimation System for the Next Generation Light Source collimation, gun, kicker, linac 2277
 
  • C. Steier, J.M. Byrd, S. De Santis, P. Emma, D. Li, H. Nishimura, C. F. Papadopoulos, H.J. Qian, F. Sannibale
    LBNL, Berkeley, California, USA
  
  Funding: This work is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Next Generation Light Source at LBNL will deliver MHz repetition rate electron beams to an array of free electron lasers. Because of the high beam power approaching one MW in such a facility, effective beam collimation is extremely important to minimize radiation damage, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the conceptual design of a collimation system, including detailed simulations to verify its effectiveness. 		 
 
WEPWA075 High-gain X-ray FELs using a Transverse Gradient Undulator in an Ultimate Storage Ring FEL, emittance, electron, storage-ring 2286
 
  • Y.T. Ding, P. Baxevanis, Y. Cai, Z. Huang, R.D. Ruth
    SLAC, Menlo Park, California, USA
  
  An “ultimate” storage ring based on PEP tunnel has been designed to achieve diffraction limited emittance (at 1.5 Angstrom)[*]. With sufficient peak current, the beam brightness of such an “ultimate” storage ring may be sufficient to drive a short-wavelength, high-gain FEL. However, the large energy spread intrinsic to storage rings hinders the FEL applications for x-ray wavelengths. To overcome this problem, we adopt the transverse-gradient undulator concept[**][***] to study a high-gain FEL in an ultimate storage ring. Using PEP-X as an example, we showed from simulations that a high-gain FEL at the photon energy 1keV with a peak power of a few hundred megawatts can be achieved within a saturation length of 100 meters.
* Y. Cai et al., Phys. Rev. ST Accel. Beams 15, 054002 (2012).
** T. Smith et al., J. Appl. Phys. 50, 4580 (1979)
*** Z. Huang, Y. Ding and C. B. Schroeder, Phys. Rev. Lett 109, 204801 (2012). 		 
 
WEPWA081 Status of the Praseodymium Undulator with Textured Dysprosium Poles for Compact X-Ray FEL Applications cryogenics, vacuum, simulation, radiation 2298
 
  • F.H. O'Shea, R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods
    RadiaBeam, Santa Monica, USA
  • J. Park, R.L. Stillwell
    NHMFL, Tallahassee, Florida, USA
  • V. Solovyov
    BNL, Upton, Long Island, New York, USA
  
  The demand for high-brightness hard x-ray fluxes from next generation light sources has spurred the development of insertion devices with shorter periods and higher fields than is feasible with conventional materials and designs. RadiaBeam Technologies is currently developing a novel high peak field, ultrashort period undulator with praseodymium-iron-boron (PrFeB) permanent magnets and textured dysprosium (Tx Dy) ferromagnetic field concentrators. This device will offer an unparalleled solution for compact x-ray light sources, as well as for demanding applications at conventional synchrotron radiation sources. A 1.4T on-axis field has already been achieved in a 9mm period undulator, demonstrating the feasibility of using Tx Dy poles in a hybrid undulator configuration with PrFeB magnets. Facets of the undulator design, optimization of the Tx Dy production and characterization process, and magnetic measurements of Tx Dy will be presented.  
 
WEPWA086 Characterization of PrFeB Permanent Magnet Blocks with Helmholtz Coils at NSLS-II cryogenics, dipole, permanent-magnet, insertion 2304
 
  • P. He, P.L. Cappadoro, T.M. Corwin, H.C. Fernandes, D.A. Harder, C.A. Kitegi, M.M. Musardo, G. Rakowsky, J. Rank, T. Tanabe
    BNL, Upton, Long Island, New York, USA
  • M. Kokole
    KYTE, Sezana, Slovenia
  
  For investigatation to build the cryogenic undulator using bake-able Praseodymium-Iron-Boron(PrFeB) magnet blocks, a short period(16.8mm) and fixed gap(5mm) hybrid undulator prototype has been fabricated at BNL. For this undulator, 36 PrFeB magnet blocks(28 type A, 4 type B, 4 type C) are used. The magnetic field characteristics of the undulator heavily depend on the directional uniformity of the magnetization of block sets. The strength and direction of magnetization of the PrFeB magnet blocks are measured using a Helmholtz coil system. The data include the three vector components of the total magnetic dipole moment of the blocks and also compare with vendor measuremeant results.  
 
WEPEA079 A New Method to Integrate s-dependent Hamiltonian insertion, insertion-device, beam-transport, focusing 2693
 
  • W. Guo
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
The present theory to obtain higher order terms of beam dynamics is mostly through Taylor expansion and differentiation, for example, the Lie transformation. When 3-dimensional Hamiltonian is being considered the operation of integration becomes necessary. In this paper we will present a new integration theory, which leads to transfer maps for common accelerator elements based on 3-d Hamiltonians. Some physics insight was also gained from this theory, for example, the kick-map theory which is used for insertion device design and modeling, is a first-order approximation in our approach. 		 
 
WEPFI057 Longitudinal Design and RF Stability Requirements for the SwissFEL Facility linac, wakefield, emittance, booster 2821
 
  • B. Beutner
    PSI, Villigen PSI, Switzerland
  
  The SwissFEL facility will produce coherent, bright, and short photon pulses covering a wavelength range down to an angstrom, requiring an emittance between 0.18 to 0.43 mm mrad at bunch charges between 10 pC and 200 pC. In nominal operation continuous changes in this range will be offered to the users to allow an individual tradeoff between photon power and pulse length. The facility consists of a S-band RF-gun, booster, and a C-band main linac, which accelerates the beam up to 5.8 GeV. Two compression chicanes will provide a nominal peak current of about 1 to 3 kA depending on the charge. The stability of RF systems is a key design issue for stable compression schemes at reliable user facilies. In this paper different operation modes are presented and discussed in terms of machine stability requirements.  
 
WEPME001 SOLEIL Beam Stability Status feedback, coupling, emittance, electron 2917
 
  • N. Hubert, L. Cassinari, J.-C. Denard, M. Labat, J.-F. Lamarre, A. Nadji, L.S. Nadolski, D. Pédeau, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  
  This paper reports recent work for improving SOLEIL electron beam stability. X-BPMs from four bending magnet beamline frontends have been inserted in the global orbit feedback loops during user operation. The corresponding source point stabilities have improved and results are reported. Some of the new beamlines request more stringent stability than the existing ones. Their requirements are not only tighter for beam orbit but also for beam size and divergence stability. For these reasons, SOLEIL has decided to define beam quality criteria for each sensitive beamline. Then it can predict ahead of commissioning how well the beamline will likely perform. A feedback on the vertical emittance, measured by a pinhole camera, has been introduced in order to reduce beam size and divergence variations due to magnetic configuration changes of a few insertion devices.  
 
WEPME035 Overview of the RF Synchronization System for the European XFEL laser, linac, LLRF, booster 3001
 
  • K. Czuba, D. Sikora, L. Zembala
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • J. Branlard, F. Ludwig, H. Schlarb, H.C. Weddig
    DESY, Hamburg, Germany
  
  One of the most important requirements for the European XFEL RF system is to assure a very precise RF field stability within the accelerating cavities. The required amplitude and phase stability equals respectively dA/A <3·10-5, dphi<0.01 deg @ 1.3GHz in the injector and dA/A<10-3, dphi <0.1 deg @1.3GHz in the main LINAC section. Fulfilling such requirements for the 3.4 km long facility is a very challenging task. Thousands of electronic and RF devices must be precisely phase synchronized by means of harmonic RF signals. We describe the proposed architecture of the RF Master Oscillator and the Phase Reference Distribution System designed to assure high precision and reliability. A system of RF cable based interferometers supported by femtosecond-stable optical links will be used to distribute RF reference signals with required short and long term phase stability. We also present test results of prototype devices performed to validate our concept.  
 
THPFI008 Experience and Benefits from PLM-based Parts Management at European XFEL cavity, controls, linac, factory 3306
 
  • L. Hagge, J.A. Dammann, S. Eucker, A. Frank, J. Kreutzkamp, D. Käfer, D. Szepielak, N. Welle
    DESY, Hamburg, Germany
  
  DESY has developed a parts management solution, which is used in the series fabrication of accelerator components for the European XFEL. The parts management solution stores assembly instructions and drawings for each component, and it tracks the assembly progress of each individual component. It offers procedures for quality inspections, for handling non-conformities and for managing changes, and it tracks the current whereabouts and the entire history of each part. The solution is based on DESY's Product Lifecycle Management (PLM) System and integrates several laboratories and suppliers. The poster shows how parts management is used at the European XFEL in the production of the super-conducting rf cavities, in the assembly of the cryomodules and in the assembly of the undulators, and discusses experience and benefits.  
 
THPFI075 Baking Test for an In-vacuum Undulator vacuum, controls, synchrotron, synchrotron-radiation 3469
 
  • L.H. Wu, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, H.P. Hsueh, J.C. Huang, C.K. Yang
    NSRRC, Hsinchu, Taiwan
  • J.-R. Chen
    National Tsing Hua University, Hsinchu, Taiwan
  
  For Taiwan Photon Source in NSRRC, the in-vacuum undulator (IU22) will be set in the straight section. The baking test took place in the NSRRC. The heating wires were welded on the outside wall of stainless chamber. The tape heaters were used for the sites without the heating wires. After acceptation test, we assemble the residual gas analysis (RGA) and extractor gauge in the IU22. The pumping down curve and RGA spectrum were recorded and investigated. It was found the slope of the pumping curve near 1 h is -0.99. When the temperature gradually increases to about 185 oC, the vacuum pressure arrives to about 8.7x10-5 Torr. The most gas source is from water before baking process. After baking test, the major residual gas includes H2, CH4, H2O, CO, and CO2. We analyze the RGA spectrum during the baking process and discuss in the paper.  
 
THPME021 Application of Magnetic Field Integral Measurement of Magnet Module to Research Alterable Gap Undulator multipole, controls, quadrupole, synchrotron 3549
 
  • H.F. Wang, W. Zhang, Q.G. Zhou
    SINAP, Shanghai, People's Republic of China
  
  A set of magnetic measurement system and a suitable magnetic field optimization method for an In-Vacuum Undulator (IVU) with alterable gaps have been developed. The method is based on assembling orders and directions of all magnet modules for correcting rms optical phase error, electron trajectory and multipole components of the IVU. Magnetic field distributions on axis and off axis of every magnet block module are measured. Then the appropriate magnetic block modules will be chosen from measured magnet modules according to a sorting algorithm and assemble them to two inner girders of an IVU. This paper will describe a magnetic field measurement system, magnetic field optimization method and optimized results of an IVU with a period of 20 mm.  
 
THPME026 First Results of the PAL-XFEL Prototype Undulator Measurements FEL, controls, radiation, insertion-device 3561
 
  • D.E. Kim, H.S. Han, Y.-G. Jung, H.-G. Lee, S.B. Lee, W.W. Lee, K.-H. Park, H.S. Suh
    PAL, Pohang, Kyungbuk, Republic of Korea
  • M.-H. Cho, I.S. Ko
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  
  Pohang Accelerator Laboratory (PAL) is developing 10 GeV, 0.1 nm SASE based FEL for high power, short pulse X-ray coherent photon sources named PAL-XFEL. At the first stage PAL-XFEL needs two undulator lines for photon source. PAL is developing undulator magnetic structure based on EU-XFEL design. The hard X-ray undulator features 7.2 mm min magnetic gap, and 5.0 m magnetic length with maximum effective magnetic field larger than 0.908 T to achieve 0.1nm radiation at 10 GeV electron energy. A prototype for PAL-XFEL Xray undulator line is completed and the measurement, correction results are summarized.  
 
THPME027 Design and Fabrication of Prototype Phase Shifter for PAL XFEL FEL, electron, controls, radiation 3564
 
  • H.-G. Lee, Y.-G. Jung, H.-S. Kang, D.E. Kim, S.B. Lee, W.W. Lee, K.-H. Park, H.S. Suh
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Pohang Accelerator Laboratory(PAL) is developing a SASE X-ray Free Electron Laser based on 10 GeV linear accelerator. Prototype phase shifters are being developed to be used for the X-ray and Soft X-ray undulator line. The phase shifters will be used to adjust the phase of the electron beam with respect to that of the radiation field. Two prototype phase shifters are being developed. One is based on the EU-XFEL phase shifter using zero-potential iron yoke, and the other one is similar to FERMI phase shifter where only permanent magnets are used. Driving system consists of 5 phase stepping motor, left/right handed ball screw and absolute linear encoder. In this paper, we describe the design, fabrication and test results of the two phase shifter prototypes.