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undulator

  
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TUZH102 Ion Instability Issues in Electron Rings electron, ion, vacuum, damping 79
 
  • T.-Y. Lee, J. Choi, H.-S. Kang
    PAL, Pohang, Kyungbuk
  The fast ion instability (FII) attracts interests recently for the International Linear Collider Project. FII was found by simulation in SLAC and later observed experimentally. Brief introduction and history of FII is given in this talk and a recent observation of FII in the PLS in-vacuum undulator is reported.  
slides icon Slides
 
TUPMA028 Status of the Photon Factory storage-ring, photon, factory, insertion 142
 
  • S. Sakanaka, S. Asaoka, W. X. Cheng, K. Haga, K. Harada, T. Honda, T. Ieiri, S. Isagawa, M. Izawa, T. Kageyama, T. Kasuga, M. Kikuchi, Y. Kobayashi, K. Kudo, H. Maezawa, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. T. Nakamura, H. Nakanishi, T. Nogami, T. Obina, K. Oide, M. Ono, T. Ozaki, C. O. Pak, H. Sakai, Y. Sakamoto, H. Sasaki, Y. Sato, T. Shioya, M. Tadano, T. Takahashi, S. Takasaki, Y. Tanimoto, M. Tejima, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto, S. I. Yoshimoto
    KEK, Ibaraki
  Two synchrotron light sources are in operation at the High Energy Accelerator Research Organization (KEK): the Photon Factory (PF) storage ring and the Photon Factory Advanced Ring (PF-AR). The 2.5-GeV PF storage ring was largely upgraded during March to September, 2005. Through this upgrade, existing ten straight sections were extended in length, and four short-straight sections were newly created. New short-period undulators were then installed in the new sections. Other developments, including a top-up injection, are in preparation. The other light source, the 6.5-GeV PF-AR, is routinely operated with a single bunch. It provides high-flux hard X-rays for research including time-resolved pulse X-ray experiments. In the PF-AR, four in-vacuum undulators and one elliptically polarized multipole wiggler are in operation. Moreover, a new in-vacuum undulator was installed in summer, 2006. Some operational developments were also carried out. In this presentation, we report both hardware and operational advances of the PF and the PF-AR storage rings.  
 
TUPMA037 Project of Infrared Storage Ring Free Electron Lasers at AIST electron, storage-ring, free-electron-laser, klystron 160
 
  • N. Sei, H. Ogawa, K. Y. Yamada, M. Y. Yasumoto
    AIST, Tsukuba, Ibaraki
  Development of free electron lasers (FELs) with a compact storage ring NIJI-IV in the near and middle infrared regions is planned in National Institute of Advanced Industrial Science and Technology (AIST). Infrared FELs with a linear accelerator have already been developed and used for various applications in many FEL facilities. However, there is no storage ring FEL (SRFEL) which can oscillate in those regions widely. Although an SRFEL is inferior to a linear accelerator FEL in the average power, it has an extremely stable wavelength and its line width is as narrow as that of a monochromatic light in a synchrotron radiation facility. The average power of the synchrotron radiation in an infrared beam line is about 10 micro-watt at most. Then the SRFEL can be expected as a light source which is more intense than the synchrotron radiation. The output power which is our target is 1 mill-watt. We are aiming at SRFEL oscillations in a wavelength region from 1 to 10 micron which include the fingerprint region partly.

sei.n@aist.go.jp

 
 
TUPMA038 Start-up of an FEL Oscillator from Shot Noise electron, radiation, simulation, free-electron-laser 163
 
  • V. Kumar, S. Krishnagopal
    RRCAT, Indore (M. P.)
  • W. M. Fawley
    LBNL, Berkeley, California
  In free-electron laser (FEL) oscillators, as in self-amplified spontaneous emission (SASE) FELs, the build-up of intra-cavity power starts from shot noise resulting from the discreteness of charge in the electron bunch. It is important to do the start-up analysis for the build-up of intracavity power in order to fix the macropulse width from the electron accelerator such that the system reaches saturation. In this paper, we show that one can use the time-dependent oscillator code GINGER [1] to perform this anlysis. we present results of this analysis for the parameters of the Compact Ultrafast TErahertz FEL (CUTE-FEL) [2] being built at RRCAT.

1. W. Fawley, 'A user Manual for GINGER and Its Post-Processor XPLOTGIN}},LBNL-49625-Rev. I' ed., Lawrence Berkley National Laboratory (2004).2. S. Krishnagopal et al., Proceedings of FEL conference (2006) 496.

 
 
TUPMA057 Physics Design of PAL-XFEL Undulator radiation, electron, linac, vacuum 190
 
  • D. E. Kim, C. W. Chung, J.-S. Oh, K.-H. Park
    PAL, Pohang, Kyungbuk
  • I. S. Ko
    POSTECH, Pohang, Kyungbuk
  Pohang Accelerator Laboratory(PAL) is planning a 0.3 nm – 0.45 nm SASE (Self Amplification of Spontaneous Emission) XFEL based on 3.7 GeV linear accelerator. It is targeting utilization of 0.1 nm X-ray radiation using the 3rd harmonic FEL radiation. With 3.7 GeV electron beam energy, achieving 0.3 nm fundamental FEL lazing is very challenging and it requires very low emittance electron beam with minimum energy spread. It also requires small period undulator with very small gap. In this context, application of SPring8 type in vacuum undulator is seriously considered. This reflects the experiences from SPring8 SCSS project. In this report, the physics design efforts of the undulator is described. The periodic parts are optimized to achieve the highest field with other requirements. The end structures were designed to be asymmetric along the beam direction to ensure systematic zero 1st field integral. The thickness of the last magnets were adjusted to minimize the transition distance to the fully developed periodic field. The final design features 4 mm minimum pole gap, 15 mm period, peak effective field of 1.09 Tesla.  
 
TUPMA058 Insertion Devices for SESAME photon, wiggler, lattice, brilliance 193
 
  • H. Tarawneh, G. Vignola
    SESAME, Amman
  SESAME is a 3rd generation synchrotron light source that is optimized for the use of Insertion Devices. In this note, the magnetic design for a Hybrid Multipole Wiggler (HMW) and an Elliptically Polarizing Undulator (EPU), proposed for the Phase-I beamlines of SESAME will be presented. Both devices fulfill the electron beam stay clear requirements defined by the SESAME lattice leading to a decent vacuum lifetime. The HMW will provide photon energies from 3-25 keV, which are defined by the scientific case of the SESAME storage ring. The HMW is a hybrid device with period length of 160 mm, a minimum gap of 14.5 mm, maximum flux density of 2.10 Tesla and total magnetic length of 3.04 m. A maximum photon flux density of 1.80×1015 photons/sec/0.1%BW is obtained. The EPU device is required to provide the SESAME users with a variable polarized light and high photon flux over the energy range of 100-1500 eV. The proposed design is of Apple-II type with a period length of 60 mm, a minimum gap of 13 mm and a total magnetic length of 1.782 m. Only the helical mode of operation has been considered where horizontal, vertical and elliptical polarized light can be obtained.  
 
WEPMA048 Beam Position Monitor at SCSS Prototype Accelerator alignment, acceleration, dipole, coupling 387
 
  • H. Maesaka, Y. Otake, T. Shintake, K. Togawa
    RIKEN Spring-8 Harima, Hyogo
  • H. Ego, T. Fukui, N. Hosoda, T. Ohshima
    JASRI/SPring-8, Hyogo-ken
  The SCSS X-ray free electron laser (XFEL) project is in progress at SPring-8. The SCSS prototype accelerator for VUV-FEL has been constructed and is in operation. The required resolution of the beam position is less than 1um for XFEL (10um for VUV-FEL). A cavity RF-BPM (Radio Frequency Beam Position Monitor) was developed for the SCSS accelerator based on the past experiment in which the position resolution of several 10nm was achieved. In the prototype accelerator, the beam-based calibration method of the RF-BPM was established. An experiment to evaluate the position resolution was also performed, and the preliminary result was obtained to be less than 5um. This result is sufficient for VUV-FEL. The RF-BPM made important contributions to the tuning of the prototype accelerator such as beam optics measurements and VUV-FEL amplification. By using RF-BPM data, for example, the envelope of the beam trajectory was visualized and the beam was straightly passed through undulators. As a result, VUV-FEL amplification was observed in the wavelength region of 40-60nm.  
 
WEPMA111 Mechanical Engineering Challenges in the Development of the FEL at RRCAT vacuum, linac, gun, laser 479
 
  • S. Chouksey, S. Krishnagopal, V. Kumar, S. Lal, K. K. Pant, V. Prasad
    RRCAT, Indore (M. P.)
  The Compact Ultrafast TErahertz Free-Electron Laser (CUTE-FEL) is being developed by BP&FEL Laboratory, RRCAT, which is designed to lase around 80 mm. Sub-systems like S-band high gradient accelerating structures, pre-buncher, buncher, pure permanent undulator etc. have already been developed and others are in advanced stage of fabrication/commissioning. In this paper we present the design, fabrication, measurements and status of various prototype developments of structures.  
 
THC3MA04 Status of the Novosibirsk High Power Terahertz FEL radiation, electron, laser, vacuum 616
 
  • S. V. Miginsky, B. A. Knyazev, E. I. Kolobanov, V. V. Kotenkov, V. V. Kubarev, G. Kulipanov, A. V. Kuzmin, A. S. Lakhtychkin, A. N. Matveenko, L. E. Medvedev, L. A. Mironenko, A. D. Oreshkov, A. V. Ovchar, V. M. Popik, T. V. Salikova, M. A. Scheglov, S. S. Serednyakov, O. A. Shevchenko, A. N. Skrinsky, N. Vinokurov
    BINP SB RAS, Novosibirsk
  • D. Kayran
    BNL, Upton, Long Island, New York
  The first stage of Novosibirsk high-power free-electron laser (FEL) was commissioned in 2003. It is based on the normal conducting CW energy recovery linac. Now the FEL provides electromagnetic radiation in the wavelength range 120–180 micrometers. The average power is 400 W. The minimum measured line width is 0.3%, which is close to the Fourier-transform limit. The assembly of user beamline is in progress, parts of the full-scale machine are manufactured. The latter will operate in the near IR region and will provide higher average power.  
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THPMA061 Numerical study of field errors due to mechanical tolerances in superconducting miniundulators simulation, linac, microtron, synchrotron 711
 
  • C. Diao, H. O. Moser
    SSLS, Singapore
  Based on a wire model, analytical formulae are derived to describe the spatial distribution of the magnetic field as determined by the parameters of the undulator including positional and orientational errors. Semi-analytical numerical simulations are performed to estimate the tolerance of the errors required for a satisfactory function of the supramini, including the effects of systematic errors (pitch, yaw and roll errors) and random errors of the wire position. The effects of these errors on the quality of the field are then graphically analyzed to show the RMS spread of the functions.  
 
THPMA062 An APPLE-II Type Helical Undulator for SSRF polarization, electron, synchrotron, radiation 714
 
  • Q. G. Zhou, M. Zhang
    SINAP, Shanghai
  Shanghai Synchrotron Radiation Facility (SSRF) is an intermediate energy (3.5GeV) light source under construction. Specially designed insertion devices will be required to realize the high brightness photon beams made possible by the low emittance electron beam. The first insertion device to be designed is a 4.2m long, 10cm period, APPLE-II type helical undulator, U10.0. The U10.0 will use a permanent magnetic configuration corresponding to four standard Halbach-type magnet rows which consist of two pairs of planar permanent magnet rows above and below the electron orbit plane. The C-frame support structure is selected. The design of U10.0, including magnetic structure, backing beams, support structures and drive systems, is described  
 
THPMA117 Design and Fabrication of Arups U6 Undulator at PLS controls, insertion, insertion-device, synchrotron 806
 
  • H.-G. Lee, C. W. Chung, H. S. Han, Y. G. Jung, D. E. Kim, W. W. Lee, K.-H. Park, H. S. Suh
    PAL, Pohang, Kyungbuk
  Pohang Accelerator Laboratory(PAL) had developed and installed an U6 undulator recently to utilize brilliant undulator radiation for ARUPS (Angle Resolved Ultraviolet Photoemission) beamline at Pohang Light Source (PLS). The U6 is a hybrid type device with period of 6 cm, minimum gap of 18 mm, maximum flux density of 0.85 Tesla and total magnetic structure length of 1830 mm. The support locations and structure of an insertion device are optimized to achieve a minimum deflection due to the magnetic loads. A Finite Element Analysis (FEA) is performed to find out the amount of maximum deflection and optimal support positions on the backing beam. The optimized maximu deflection is estimated to be about 11.6 ?, while the deflection before any optimization is 48.8 ?. In this report, all the mechanical design, fabrication and assembly details of the PLS U6 undulator are described.