IBIC2017 - List of Authors (Harada, H.)

Paper	Title	Page
TUPCF12	Measurement of Each 324 MHz Micro Pulse Stripping Efficiency for H⁻ Laser Stripping Experiment in J-PARC RCS	233
	P.K. Saha, H. Harada, N. Hayashi, A. Miura, K. Okabe, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In 3-GeV RCS of J-PARC, an experiment for H⁻ stripping to protons by using lasers is under preparation. The experiment requires measurements of all three charge fractions of each 324 MHz H-μpulse in the downstream of laser and H⁻ interaction point (IP). However, at the first stage, only a single H-μpulse is aimed to strip by using lasers. It is therefore very essential to establish a new measurement method for that purpose, which has not yet been studied anywhere in that direction. We consider measuring BPM (beam position monitor) pickup signal by using an oscilloscope of 4 GHz bandwidth and sampling rate no less than 1TS/s. To test the system, we have done some experimental studies, where beam halo scrapper (carbon foil), placed at the L-3BT (linac to 3-GeV beam transport) is used for H⁻ stripping. The unstripped H⁻ and the stripped protons separated by a bending magnet in the downstream of the scrapper are simultaneously measured by two BPMs in two beam lines. The H-μpulses were clearly measured with good resolution, where a ratio of the pulses without and with scrapper gives the stripping efficiency. A detail of the present study results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPCF12
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WEPWC09	New Scintillation Type Beam Loss Monitor to Detect Spot Area Beam Losses in the J-PARC RCS	461
	M. Yoshimoto, H. Harada, S. Kato, M. Kinsho, K. Okabe JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the J-PARC RCS, a large fraction of our effort has been concentrated on reducing and managing beam losses to achieve 1MW high power proton beam operation. Standard beam loss monitor (BLM), which is installed outside of the magnet in every cell of beam optics and detect the beam loss at wide area in each cell, is insufficient to investigate finer beam loss mechanism in the ring. Thus we developed new scintillation type BLM to detect the beam loss at spot area on the vacuum chamber inside the magnet. The new BLM has separating structure a photomultiplier (PMT) from a plastic scintillator and connecting with optical fibres. Because small plastic scintillator is installed on the vacuum chamber directly, it has capability to have high sensitivity for localized spot area beam loss. On the other hand, the PMT can precisely be operated without being affected by magnetic field by keeping the PMT from the magnet. In this presentation, we report the detail of the performance of the new BLM.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPWC09
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Measurement of Each 324 MHz Micro Pulse Stripping Efficiency for H⁻ Laser Stripping Experiment in J-PARC RCS

233

P.K. Saha, H. Harada, N. Hayashi, A. Miura, K. Okabe, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In 3-GeV RCS of J-PARC, an experiment for H⁻ stripping to protons by using lasers is under preparation. The experiment requires measurements of all three charge fractions of each 324 MHz H-μpulse in the downstream of laser and H⁻ interaction point (IP). However, at the first stage, only a single H-μpulse is aimed to strip by using lasers. It is therefore very essential to establish a new measurement method for that purpose, which has not yet been studied anywhere in that direction. We consider measuring BPM (beam position monitor) pickup signal by using an oscilloscope of 4 GHz bandwidth and sampling rate no less than 1TS/s. To test the system, we have done some experimental studies, where beam halo scrapper (carbon foil), placed at the L-3BT (linac to 3-GeV beam transport) is used for H⁻ stripping. The unstripped H⁻ and the stripped protons separated by a bending magnet in the downstream of the scrapper are simultaneously measured by two BPMs in two beam lines. The H-μpulses were clearly measured with good resolution, where a ratio of the pulses without and with scrapper gives the stripping efficiency. A detail of the present study results are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-TUPCF12

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWC09

New Scintillation Type Beam Loss Monitor to Detect Spot Area Beam Losses in the J-PARC RCS

461

M. Yoshimoto, H. Harada, S. Kato, M. Kinsho, K. Okabe
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the J-PARC RCS, a large fraction of our effort has been concentrated on reducing and managing beam losses to achieve 1MW high power proton beam operation. Standard beam loss monitor (BLM), which is installed outside of the magnet in every cell of beam optics and detect the beam loss at wide area in each cell, is insufficient to investigate finer beam loss mechanism in the ring. Thus we developed new scintillation type BLM to detect the beam loss at spot area on the vacuum chamber inside the magnet. The new BLM has separating structure a photomultiplier (PMT) from a plastic scintillator and connecting with optical fibres. Because small plastic scintillator is installed on the vacuum chamber directly, it has capability to have high sensitivity for localized spot area beam loss. On the other hand, the PMT can precisely be operated without being affected by magnetic field by keeping the PMT from the magnet. In this presentation, we report the detail of the performance of the new BLM.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPWC09

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)