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TUPMA015 Radiation Safety Considerations of the Operation of INDUS-1 Synchrotron Radiation Source radiation, shielding, storage-ring, synchrotron 121
 
  • H. Nair, V. Dev, M. K. Nayak, V. Verma, thakkar,k.k. thakkar
    RRCAT, Indore (M. P.)
  • P. K. Sarkar
    DAE/VECC, Calcutta
  • D. N. Sharma
    Bhabha Atomic Research Centre, Trombay, Mumbai
  Radiological safety aspects of the operation of the electron storage ring, Indus-1 (450 MeV, 100 mA) is described in the paper. The ring is provided with a modular hybrid shielding comprising of mild steel and lead through which synchrotron radiation (SR) beam lines pass out. During the commissioning phase several radiation protection problems like streaming of high-energy bremsstrahlung x-rays, through front ends of SR beam lines, shield joints, its detection and containment were encountered. Experimental measurements on the response of conventional radiation monitors with respect to water phantom were then carried out to evaluate the dose build up factors in the streaming high-energy radiation field. The studies lead to the deduction of correction factors for the monitors for use in Indus-1. Improvement in monitor response on account of spectral degradation through shield and radiation levels during accidental beam loss are other problems, which are evaluated. Details of the radiation protection programme, radiation physics studies, the current status of radiation levels and access control are presented.  
 
TUPMA020 Beam Based Alignment and COD Correction for the Siam Photon Source quadrupole, controls, alignment, betatron 130
 
  • S. Rugmai, S. Rugmai
    Suranaree University of Technology, Nakhon Ratchasima
  • P. Klysubun, C. Kwankasem, P. Sudmuang
    NSRC, Nakhon Ratchasima
  The first systematic Beam based Alignment (BBA) and COD correction attempt for the Siam Photon Source has been performed. Automated measurements were carried out using MATLAB OPC Toolbox, interfacing to the PLCs of the accelerator control system. Calculations of theoretical parameters were performed with Accelerator Toolbox via MATLAB interface. Since the Beam Position Monitors (BPMs) were not properly calibrated prior to installation beam based calibrations were carried out. Preliminary calibration factors for each BPM were obtained by normalizing BPM signals to modeled steering magnet responses. Measurements of offsets between BPM and quadrupole centers were performed by fitting for minima of orbit response to changes of quadrupole strengths. The resulting offsets were superimposed to the BPM readings in the PLC. COD correction was then performed.  
 
TUPMA028 Status of the Photon Factory undulator, storage-ring, 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.  
 
TUPMA034 Operation Experience of Top-up injection at Taiwan Light Source injection, storage-ring, beam-losses, insertion-device 151
 
  • G.-H. Luo, H.-P. Chang, C.-T. Chen, J. Chen, J.-R. Chen, C.-C. Kuo, K. S. Liang, Y.-C. Liu, R. J. Sheu, D.-J. Wang
    NSRRC, Hsinchu
  The storage ring of Taiwan Light Source (TLS) has one Superconducting (SC) cavity, one SC wavelength shifter, and two SC wigglers installed during last two years. The operation mode was also upgraded to have the capability of top-up injection. Top-up is an operation mode in which the beam current is maintained above certain level by frequent injections in the storage ring. The current stability maintains in the range of 10-3 for long period of operation. It provides constant thermal loading on all components in the storage ring and the optics components of beamlines, as well as constant signal to the beam position monitor. The top-up injection is a routine operation mode during user shifts at TLS. Statistics, operation experience and future expansion will be discussed in this paper.  
 
TUPMA046 Future Light Source based on Energy Recovery Linac in Japan linac, gun, emittance, factory 172
 
  • T. Kasuga, T. Furuya, H. Kawata, Y. Kobayashi, S. Sakanaka, K. Satoh
    KEK, Ibaraki
  • R. Hajima
    JAEA/FEL, Ibaraki-ken
  • N. Nakamura
    ISSP/SRL, Chiba
  After extensive discussions on the future light source of the Photon Factory at High Energy Accelerator Research Organization (KEK), it has been concluded that a 5 GeV energy recovery linac (ERL) should be the most suitable candidate to foster cutting edge experiments and support a large variety of user needs from VUV to X-rays. On the other hand, Japan Atomic Energy Agency (JAEA), which has already built a low energy (17 MeV) ERL, also proposed its own 5-6 GeV ERL as a light source. These two institutes with a participation of the members of the Institute for Solid State Physics (ISSP) of the University of Tokyo agreed to promote an ERL-based next-generation synchrotron light source in Japan. In order to realize a 5 GeV ERL, it is necessary to construct a prototype ERL with an energy of ~200 MeV and develop several critical components such as electron guns and superconducting accelerating structures. We are planning to construct together the prototype ERL at the KEK site. An R&D team for the prototype ERL is going to be organized in collaboration with accelerator scientists from the other facilities, UVSOR and SPring-8.  
 
TUPMA058 Insertion Devices for SESAME undulator, 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.  
 
WEPMA054 Photon Beam Position Monitor with Hydraulic Level System storage-ring, diagnostics, feedback, controls 398
 
  • Y. J. Han, J. Choi, J. Y. Huang, S. N. Kim, Y.-C. Kim
    PAL, Pohang, Kyungbuk
  • I. S. Ko
    POSTECH, Pohang, Kyungbuk
  In a synchrotron radiation source like the Pohang Light Source (PLS), a great effort has been made on beam stability improvements. For the beamline user-sided orbit feedback, Photon Beam Position Monitor(PBPM) provides more practical informations on the position and angle of the electron beam at the center of the bending magnet, compared the closed orbit data. For improvement of the orbit stability, PBPMs are used in PLS. However, as the ground of PLS moves about 2mm every year, we also monitor the level difference between the storage ring and the beamline floor with Hydraulic Level System (HLS). The design and experimental results of PBPM with HLS will be presented.  
 
WEPMA099 A New, PXI Bus Based, Pattern Memory System for the Siam Photon Source. power-supply, synchrotron, booster, controls 461
 
  • G. G. Hoyes
    NSRC, Nakhon Ratchasima
  A new pattern memory system has been built from PXI bus modules to ramp the booster synchrotron magnet and RF power supplies, replacing an old and proprietary Toshiba system. The new system is compact, rugged, easy to program using LabVIEW, easy to repair and low cost.  
 
WEPMA109 Positron Injector Accelerator and RF System for the ILC positron, target, electron, linac 473
 
  • J. W. Wang, C. Adolphsen, V. Bharadwaj, G. B. Bowden, E. N. Jongewaard, Z. Li, R. H. Miller, J. Sheppard
    SLAC, Menlo Park, California
  Due to the extremely high energy deposition from positrons, electrons, photons and neutrons behind the positron target, and because a solenoid is required to focus the large emittance positron beam, the 1.3 GHz pre-accelerator has to use normal conducting structures up to energy of 400 MeV. There are many challenges in the design of the normal-conducting portion of the ILC positron injector system such as obtaining high positron yield with required emittance, achieving adequate cooling with the high RF and particle loss heating, and sustaining high accelerator gradients during millisecond-long pulses in a strong magnetic field. Considering issues of feasibility, reliability and cost savings for the ILC, the proposed design for the positron injector contains both standing-wave (SW) and traveling-wave (TW) L-band accelerator structures. A short version of the new type of the SW section is under fabrication and testing, an updated status report is given. This paper also covers the acceleration vs. deceleration for pre accelerator sections, SW vs. TW structures, as well as the longitudinal matching from target to linac and linac to damping ring.

* Work supported by U. S. Department of Energy, contract DE-AC02-76SF00515.

 
 
THYMA03 Commissioning Experience of Superconducting Radio Frequency Systems for the Taiwan Light Source cryogenics, vacuum, synchrotron, feedback 549
 
  • Ch. Wang, L.-H. Chang, M. H. Chang, S.-S. Chang, F.-T. Chung, F. Z. Hsiao, M.-C. Lin, Y.-H. Lin, M. H. Tsai, T.-T. Yang, M.-S. Yeh
    NSRRC, Hsinchu
  An industrially manufactured CESR-type SRF module has been routinely operated at the Taiwan Light Source (TLS) at the National Synchrotron Radiation Research Center (NSRRC) since the beginning of March 2005. The original goals of doubling the electron beam current to increase the synchrotron light intensity and of eliminating the instability caused by the interaction of the electron beams with the cavity's higher-order modes have been successfully demonstrated. The greatest challenge to the operational reliability is the shortness of the mean time between failures, and has been successfully overcome. This work reports the commissioning experience of the SRF module at TLS for high beam-current operation toward a maximum beam current of 400 mA in top-up mode from 200 mA in decay mode over last two years. Emphasized will be the instrument development for analysis of SRF trip event and the continuous improvements of the operating analogous low-level rf system against instability of feed back loops caused by heavy beam loading.  
slides icon Slides
 
THC3MA01 Operation and Recent Developments at the Siam Photon Source storage-ring, synchrotron, insertion, insertion-device 607
 
  • P. Klysubun, S. Cheedket, G. G. Hoyes, C. Kwankasem, M. Oyamada, S. Rugmai, S. Rujirawat
    NSRC, Nakhon Ratchasima
  The Siam Photon Source (SPS) is a dedicated synchrotron radiation facility located in Nakhon Ratchasima, Thailand. After successful commissioning and recent energy upgrade from 1.0 GeV to 1.2 GeV, the Siam Photon Source is currently well into user mode of operation. The light source is now providing routinely synchrotron radiation in the vacuum ultraviolet and soft x-ray spectral ranges to both internal and external researchers. In this report we describe the overview of the current machine performance including user availability, the progresses made recently, and the planned machine improvements, which emphasizes on improving beam stability and machine reliability. Plan to install two insertion devices, a permanent magnet planar undulator and a superconducting magnet wavelength shifter, is also discussed.  
slides icon Slides
 
THPMA059 The Vacuum System for the SSRF Storage Ring vacuum, storage-ring, radiation, synchrotron 708
 
  • D. K. Jiang
    SINAP, Shanghai
  SSRF is the first third generation light source in China. The storage ring vacuum system adopts SUS316LN material chambers with antechamber structure and discrete absorbers. There are several types of absorbers in the storage ring. TSP and SIP+NEG combined pumps are used. A single finger RF shielded structure is applied in bellows. The models of vacuum chambers (SUS316L material), absorbers and combined pumps (SIP 200l/s + NEG WP1250) were developed and tested. In order to check the vacuum system design and the fabrication technology, the model components were installed together with magnets and girders to forming a standard cell prototype.

Only for poster

 
 
THPMA088 Bremsstrahlung Converter For High Power EB Radiation Processing Facility electron, target, radiation, radioactivity 767
 
  • V. C. Petwal, S. C. Bapna, S. Kotaiah, R. S. Sandha
    RRCAT, Indore (M. P.)
  • K. V. Subbaiah
    Safety Research Institute, Indira Gandhi Center for Atomic Research, Tamilnadu
  A radiation processing facility based on 10 kW Linac is being set up at RRCAT for irradiation of food products and sterilization of medical items. The facility is planned to operate in electron (10 MeV) and X-ray (5 & 7.5 MeV)mode. The required X-rays will be generated by bombarding an optimised target with 5 or 7.5 MeV electron beam. Monte Carlo simulation with MCNP has been performed to optimise the design of the targets for maximizing the X-ray output. The composite target is made of Ta, water & SS. Characteristics of the emerging X-ray field e.g. photon energy spectrum, angular distribution, radial dose and depth dose distribution in unit density material have been simulated & compared for 5 & 7.5 MeV. Our simulation results show that for optimised design, the fraction of the energy transmitted at 5 & 7.5 MeV is 9.3% & 14.2 % respectively, which is useful for radiation processing. The most probable energy of the photons is 0.3 MeV for both 5 and 7.5 MeV electrons and the average energy is 0.84 MeV & 1.24 MeV respectively. Large fraction of electron beam power is dissipated as heat in the targets. Necessary data has been generated to carry out thermal design.