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Huang, J.Y.

Paper Title Page
MPPP003 FALSE BPM READINGS AFFECTING ORBIT FEEDBACK 847
 
  • H.-S. Kang, J. Choi, M.-H. Chun, K.M. Ha, J.Y. Huang, Y.-C. Kim, E.-H. Lee, T.-Y. Lee, W.W. Lee, J.-H. Suh
    PAL, Pohang, Kyungbuk
 
  Funding: Ministry of Science and Technology, Korea.

A slow global orbit feedback (SOFB) is routinely operating in the usual user service operation at PLS. The orbit feedback uses 22 correctors in each plane which have 20-bit capability for the vertical plane and 16-bit capability for the horizontal plane, and the feedback speed is 4 seconds. The orbit stability in RMS was maintained below 1 mm in both planes for one hour and 3 mm for a 12-hour operation. The BPM chamber movement due to the change of synchrotron radiation heat load mainly limits the SOFB performance. The intensity dependence of BPM electronics is well compensated by a look-up table of BPM.

 
WPAE061 LC Filter for High Accuracy and Stability Digital MPS at PLS 3550
 
  • S.-C. Kim, J. Choi, K.M. Ha, J.Y. Huang
    PAL, Pohang, Kyungbuk
 
  Funding: Work supported by the Ministry of Science and Technology, Korea.

High accuracy and stability digital power supply for magnet is developed at PLS. This power supply has three sections. The first section is digital controller including DSP&FPGA and precision ADC, the second consists of IGBT driver and four quad IGBT switch, and the third is LC output section. AC input voltage of power supply is 3-phase 21V, output current is 0 ~ 150 A dc. Switching frequency of IGBT is 25 kHz. The output current of power supply has very high accuracy of 100 mA step resolution at full range and the stability of ± 1.5 ppm for short term and ± 5 ppm for long term. This paper describes characteristics of filter and output current performance improvement after LC output filter at four quad digital power supplies.

 
RPAT007 Status of Beam Diagnostic Systems for the PEFP 1090
 
  • J.H. Park, J.Y. Huang, W.H. Hwang, Y.W. Parc, S.J. Park
    PAL, Pohang, Kyungbuk
  • Y.-S. Cho, B.H. Choi, S.-H. Han
    KAERI, Daejon
 
  Funding: Supported by the PEFP (Proton Engineering Frontier Project).

A proton linear accelerator is currently the construction at the KAERI (Korea Atomic Research Institute) to the PEFP (Proton Engineering Frontier Project) in Korea. We are accomplished the technique development of beam diagnostic system to be currently the construction. We treat beam diagnostics for the high power proton linear accelerator. Prototype beam position & phase monitor (BPPM) electronics was made and tested successfully in one of the beam diagnostic systems. The beam position monitor pickup electrode is a capacitive type (electrostatic type) which has a button form. Button form electrode, in common use around electron synchrotrons and storage rings, are a variant of the electrode with small button form (e.g., sub mm diameter). However, we are designed button form electrode to measure beam position of proton beam. The BCM (Beam Current Monitor) is developed Tuned CT (Current Transformer) for collaborate with Bergoz Instruments. This paper describes the status of beam diagnostic systems for the PEFP.

 
RPAT054 Beam Position Monitor at the PLS BTL 3289
 
  • S.-C. Kim, M.-H. Chun, Y.J. Han, J.Y. Huang, D.T. Kim, W.W. Lee
    PAL, Pohang, Kyungbuk
 
  Funding: Work supported by the Ministry of Science and Technology, Korea.

Electron Linac at the Pohnag Accelerator Laboratory (PAL) has been operated continuously as the full energy injector for storage ring. Linac and storage ring energy has been 2.0 GeV since Dec. 1994, and 2.5 GeV since Oct. 2002. In Aug. 2004, thirteen BPMs are newly installed at BTL(Beam Transport Line) for beam trajectory measurement and feedback. These BPMs consist of 100mm strip-line electrodes in 150mm long chamber, and 500MHz log-ratio signal processing circuits. BPM data acquisition system is developed as EPICS IOC using NI S-series data acquisition board and NI LabView 7.1. BTL BPMs will be used for optic correction and beam energy feedback for PLS beam injection. This paper describes on design, test results, installation and data acquisition system of the PLS BTL BPM.

 
ROPB005 Recent Experiment Results on Fast Ion Instability at 2.5 GeV PLS 466
 
  • E.-S. Kim, Y.J. Han, J.Y. Huang, I.S. Ko, P.C.D. Park, S.J. Park
    PAL, Pohang, Kyungbuk
  • H. Hukuma, H. Ikeda
    KEK, Ibaraki
 
  We present recent experiment results on the fast ion instability that were performed at the PLS storage ring. With higher vacuum pressures of three orders of magnitude than nominal one by He gas injection into the ring, increases of a factor of around three in the vertical beam size were observed by interferometer system. From the various measurement results, we estimated growth times for the instability as a funcion of vacuum pressure and beam current. We also compared the results with those of the computer simulations and analytical calculations.  
RPPT031 Recent Results from and Future Plans for the VISA II SASE FEL 2167
 
  • G. Andonian, R.B. Agustsson, P. Frigola, A.Y. Murokh, C. Pellegrini, S. Reiche, J.B. Rosenzweig, G. Travish
    UCLA, Los Angeles, California
  • M. Babzien, I. Ben-Zvi, V. Litvinenko, V. Yakimenko
    BNL, Upton, Long Island, New York
  • I. Boscolo, S. Cialdi, A.F. Flacco
    INFN-Milano, Milano
  • M. Ferrario, L. Palumbo, C. Vicario
    INFN/LNF, Frascati (Roma)
  • J.Y. Huang
    PAL, Pohang, Kyungbuk
 
  As the promise of X-ray Free Electron Lasers (FEL) comes close to realization, the creation and diagnosis of ultra-short pulses is of great relevance in the SASE FEL (Self-Amplified Spontaneous Emission) community. The VISA II (Visible to Infrared SASE Amplifier) experiment entails the use of a chirped electron beam to drive a high gain SASE FEL at the Accelerator Test Facility (ATF) in Brookhaven National Labs (BNL). The resulting ultra-short pulses will be diagnosed using an advanced FROG (Frequency Resolved Optical Gating) technique, as well as a double differential spectrum (angle/wavelength) diagnostic. Implementation of sextupole corrections to the longitudinal aberrations affecting the high energy-spread chirped beam during transport to the VISA undulator is studied. Start-to-end simulations, including radiation diagnostics, are discussed. Initial experimental results involving a highly chirped beam transported without sextupole correction, the resulting high gain lasing, and computational analysis are briefly reported.  
RPPP003 Proposal of the Next Incarnation of Accelerator Test Facility at KEK for the International Linear Collider 874
 
  • H. Hayano, S. Araki, H. Hayano, Y. Higashi, Y. Honda, K.-I. Kanazawa, K. Kubo, T. Kume, M. Kuriki, S. Kuroda, M. Masuzawa, T. Naito, T. Okugi, R. Sugahara, T. Tauchi, N. Terunuma, N. Toge, J.U. Urakawa, V.V. Vogel, H. Yamaoka, K. Yokoya
    KEK, Ibaraki
  • I.V. Agapov, G.A. Blair, G.E. Boorman, J. Carter, C.D. Driouichi, M.T. Price
    Royal Holloway, University of London, Surrey
  • D.A.-K. Angal-Kalinin, R. Appleby, J.K. Jones, A. Kalinin
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • P. Bambade
    LAL, Orsay
  • K.L.F. Bane, A. Brachmann, T.M. Himel, T.W. Markiewicz, J. Nelson, N. Phinney, M.T.F. Pivi, T.O. Raubenheimer, M.C. Ross, R.E. Ruland, A. Seryi, C.M. Spencer, P. Tenenbaum, M. Woodley
    SLAC, Menlo Park, California
  • S.T. Boogert, A. Liapine, S. Malton
    UCL, London
  • H.-H. Braun, D. Schulte, F. Zimmermann
    CERN, Geneva
  • P. Burrows, G.B. Christian, S. Molloy, G.R. White
    Queen Mary University of London, London
  • J.Y. Choi, J.Y. Huang, H.-S. Kang, E.-S. Kim, S.H. Kim, I.S. Ko
    PAL, Pohang, Kyungbuk
  • S. Danagoulian
    North Carolina A&T State University, Greensboro, North Carolina
  • N. Delerue, D.F. Howell, A. Reichold, D. Urner
    OXFORDphysics, Oxford, Oxon
  • J. Gao, W. Liu, G. Pei, J.Q. Wang
    IHEP Beijing, Beijing
  • B.I. Grishanov, P.L. Logachev, F.V. Podgorny, V.I. Telnov
    BINP SB RAS, Novosibirsk
  • J.G. Gronberg
    LLNL, Livermore, California
  • Y. Iwashita, T. Mihara
    Kyoto ICR, Uji, Kyoto
  • M. Kumada
    NIRS, Chiba-shi
  • S. Mtingwa
    North Carolina University, Chapel Hill, North Carolina
  • O. Napoly, J. Payet
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • T.S. Sanuki, T.S. Suehara
    University of Tokyo, Tokyo
  • T. Takahashi
    Hiroshima University, Higashi-Hiroshima
  • E.T. Torrence
    University of Oregon, Eugene, Oregon
  • N.J. Walker
    DESY, Hamburg
 
  The realization of the International Linear Collider (ILC) will require the ability to create and reliably maintain nanometer size beams. The ATF damping ring is the unique facility where ILC emittancies are possible. In this paper we present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and an ILC-like bunch train, would be capable of achieving 35nm beam size. Such a facility would enable the development of beam diagnostics and tuning methods, as well as the training of young accelerator physicists.