Takeshi Toyama (High Energy Accelerator Research Organization)
WEP12
A development of wide dynamic-range halo monitor for 8 GeV proton beams at FNAL
274
The FNAL accelerator complex has been upgrading in increasing beam intensity and beam quality. A new beam halo diagnostic device is required in the beam transport line between booster and Recycler. For this purpose, it was decided to introduce the wide dynamic range monitor technique that was developed in 2012 and has been in operation at the J-PARC beam transport line. The device is a two-dimensional beam profile monitor, and it has a dynamic range of approximately six digits of magnitude by using of Optical Transition Radiation and fluorescence screens. Eliminating harmful beam halos is the most important technique for high-intensity proton accelerators. Therefore, beam halo diagnosis is indispensable and becomes more and more important. New FNAL device has been manufactured in a collaboration between J-PARC and FNAL as a part of U.S.-Japan Science and Technology Cooperation Program in High Energy Physics. The equipment will be manufactured at J-PARC and will be shipped to FNAL in 2025. We designed the device to satisfy FNAL specifications: the beam energy, intensity, and size. Currently, most of the equipments are under construction. The large-aperture optical system has been completed and its optical characteristics are being evaluated at J-PARC. We have been also investigating measurement methods corresponding to FNAL bunch trains. This paper reports on the current status of these developments.
  • Y. Hashimoto, T. Toyama, T. Sasaki, T. Mitsuhashi
    High Energy Accelerator Research Organization
  • C. Ohmori
    Japan Proton Accelerator Research Complex (J-PARC)
  • H. Sakai
    Kanto Information Service (KIS), Accelerator Group
  • M. Uota, M. Tejima
    KEK
  • R. Ainsworth
    Fermi National Accelerator Laboratory
  • Y. Sato
    Japan Proton Accelerator Research Complex
Paper: WEP12
DOI: reference for this paper: 10.18429/JACoW-IBIC2024-WEP12
About:  Received: 18 Sep 2024 — Revised: 20 Sep 2024 — Accepted: 20 Sep 2024 — Issue date: 11 Dec 2024
Cite: reference for this paper using: BibTeX, LaTeX, Text/Word, RIS, EndNote
WEP36
Transverse feedback to damp collective beam instabilities, past, present and future
350
tarting with my first experience of the transverse feedback damper in the KEK 12 GeV PS in 2005 - 2006, where we tested with analog system and in addition digital control-ler from SPring-8 team. Since then, digital systems have come to cover almost all the machines. In J-PARC MR bunch-by-bunch transverse feedback system had been introduced with a collaboration at the proton beam power around 150 kW in 2010. The weaknesses of this system quickly became apparent. It can damp only the center-of-mass motion of each bunch. It could not suppress intra-bunch betatron motion with different betatron phase in a different longitudinal bunch position. This happens in the case of a non-zero chromaticity. Then the intra-bunch feedback system was introduced in 2014 with a proton beam power of approximately 250 kW and has been operating successfully to date. But already this system cannot suppress collective beam instabilities in certain chromaticities over proton beam intensity of 2 - 3E+14 protons per pulse. The higher the sampling rate, the higher the damp-ing efficiency. This system is currently under development.
  • T. Toyama
    High Energy Accelerator Research Organization
Paper: WEP36
DOI: reference for this paper: 10.18429/JACoW-IBIC2024-WEP36
About:  Received: 13 Sep 2024 — Revised: 13 Sep 2024 — Accepted: 13 Sep 2024 — Issue date: 11 Dec 2024
Cite: reference for this paper using: BibTeX, LaTeX, Text/Word, RIS, EndNote