RESEARCH ON BEAM FLATTENING BY USING THE HIGHER HARMONIC CAVITY IN THE HIGH INTENSITY PROTON ACCELERATOR.

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17540277
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: JAPAN ATOMIC ENERGY AGENCY
• Principal Investigator: IRIE Yoshiro JAEA, J-PARC CENTER, SENIOR PRINCIPAL RESEARCHER, 量子ビーム応用研究部門, 研究主席 (00124173)
• Co-Investigator(Kenkyū-buntansha): OKI Toshiyuki UNIV. OSAKA, FACULTY OF SCIENCE, RESEARCH ASSOCIATE, 大学院理学研究科, 助手 (60415049) ; TAKAGI Akira KEK, ACCELERATOR LAB., LECTURER, 加速器研究施設, 講師 (10100819) ; FUKUMOTO Sadayoshi KEK, PROFESSOR EMERITUS, 加速器研究施設, 名誉教授 (90029637) ; YOSHII Masahito KEK, ASSOCIATE PROFESSOR, 大強度陽子加速器計画推進部, 助教授 (00200931) ; YAMAMOTO Masanobu JAEA, J-PARC CENTER, RESEARCHER, 量子ビーム応用研究部門, 研究員 (30354749)
• Project Period (FY): 2005 – 2006
• Keywords: high intensity proton accelerator / second harmonic cavity / beam flattening / beam loading / low output impedance

Research Abstract

It is essential to form a flattened bunch shape in a high intensity proton accelerator from view point of mitigation of the space charge effect. The second harmonic cavity is used for this end, where precise control of the cavity phase to the fundamental one is required. This project is intended for the beam experiments at the world highest proton synchrotron facility, ISIS, Rutherford Appleton Laboratory (RAL), UK in order to investigate the space charge effects by using the low-output impedance (LOI) second harmonic cavity. Since the LOI cavity is free from beam loading, precise control of the cavity phase can be achieved.
In August, 2005, we succeeded in producing a required RF voltage, 12.6kV per gap, for the LOI system : the frequency was swept at 50Hz from 2.6 to 6.2MHz, and the output impedance less than 30ohms. Although a problem on waveform distortions in the driver stage remained to be solved, the LOI system became almost ready for installation into the ISIS synchrotron for beam test.
In 2006, however, a new project on the muon ionization cooling experiment (MICE project) came up at the RAL. The experimental area we have used so far was allocated for this project, and we had no choice but to move elsewhere. The Hall 2 of the ISIS facility was refurbished to accommodate our LOI system. The movement of the LOI and re-cabling of all the power lines and control lines began in October, 2006. By the end of March, 2007, these works have been completed. Therefore, the proposed experimental research could not be performed : the beam experiments are foreseen in Fy2007 or later.

Research Products

• [Journal Article] Low-impedance RF system with a new type of feedback amplifier for a high-intensity synchrotron under heavy beam loading. (2006)
  • Author(s): T.Oki, Y.Irie, S.Takano, LOI collaboration team.
  • Journal Title: Nuclear Instruments and Methods in Physics Research A 565 Pages: 358-369
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Wideband low-output-impedance RF system for the second harmonic cavity in the ISIS synchrotron. (2006)
  • Author(s): Y.Irie, J.Dooling, D.Horan, R.Kustom, M.Middendorf, G.Pile, D.Bayley, G.Cross, I.Garder, M.Glover, D.Jenkins, A.Morris, A.Seville, S.Stoneham, J.Thomason, T.Western, S.Fukumoto, K.Muto, T.Oki, A.Takagi, S.Takano
  • Journal Title: Proc. of European Particle Accelerator Conference 2006 Pages: 321-323
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Low-impedance RF system with a new type of feedback amplifier for a high-intensity synchrotron under heavy beam loading (2006)
  • Author(s): T.Oki, Y.Irie, S.Takano, LOI collaboration team
  • Journal Title: Nuclear Instruments and Methods in Physics Research A 565 Pages: 358-369
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Wideband low-out put-impedance RF system for the second harmonic cavity in the ISIS synchrotron (2006)
  • Author(s): Y.Irie, J.Dooling, D.Horan, R.Kustom, M.Midde ndorf, G.Pile, D.Bayley, G.Cross, I.Carder, M.Glover, D.Jenkins, A.Morris, A.Seville, S.Sto neham, J.Thomason, T.Western, S.Fukumoto, K.Muto, T.Oki, A.Takagi, S.Takano
  • Journal Title: Proc. of European Particle Accelerator Conference Pages: 321-323
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Dual Harmonic Operation with Broadband MA Cavities in J-PARCRCS (2005)
  • Author(s): M.Yamamoto, M.Nomoura, A.Schnase, F.Tamura, S.Anami, E.Ezura, K.Hara, Y.Hashimoto, C.Ohmori, A.Takagi, M.Yoshii
  • Journal Title: Proc. of Particle Accelerator Conference 2005 Pages: 931-933
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Cascaded Integrator Comb Filters with Smoothly Varying Coefficients for Reduced Delay in Synchrotron Feedback Loops (2005)
  • Author(s): A.Schnase, M.Nomura, F.Tamura, M.Yamamoto, S.Anami, E.Ezura, K.Hara, C.Ohmori, A.Takagi, M.Yoshii
  • Journal Title: Physical Review Special Topics-Accelerators and Beams 8・122001 Pages: 1-19
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Dual Harmonic Operation with Broadband MA Cavities in J-PARC RCS (2005)
  • Author(s): M.Yamamoto, M.Nomoura, A.Schnase, F.Tamura, S.Anami, E.Ezura, K.Hara, Y.Hashimoto, C.Ohmori, A.Takagi, M.Yoshii
  • Journal Title: Proc. of Particle Accelerator Conference Pages: 931-933
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Cascaded Integrator Comb Filters with Smoothly Varying Coefficients for Reduced Delay in Synchrotron Feedback Loops (2005)
  • Author(s): A.Schnase, M.Nomura, F.Tamura, M.Yamamoto, S.Anami, E.Ezura, K.Hara, C.Ohmori, A.Takagi, M.Yoshii
  • Journal Title: Physical Review Special Topics-Accelerators and Beams 8-122001 Pages: 1-19
  • Description: 「研究成果報告書概要(欧文)」より