IBIC2015 - List of Authors (Hayashi, N.)

Paper	Title	Page
TUPB026	Machine Stability Analysis by Pulse Based Data Archiver of the J-PARC RCS	381
	N. Hayashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The J-PARC RCS (Rapid-Cycling proton Synchrotron) runs with repetition rate of 25 Hz. The beam intensity of current monitors and beam loss monitors (BLM) data are archived for all pulses and they could be analyzed to study the machine stability. In addition BPM data are also recorded in regularly (2 seconds with every minutes) and particularly in case of the RCS MPS, the last several hundreds BPM data are recorded. We will report a few examples, in the case of magnet feedback problem or vacuum problem, how the BPM or BLM behaves.
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TUPB027	Bunch Length Analysis of Negative Hydrogen Ion Beam in J-PARC Linac	386
	A. Miura, N. Hayashi JAEA/J-PARC, Tokai-mura, Japan S. Fukuoka University of Tsukuba, Graduate School of Pure and Applied Sciences,, Tsukuba, Ibaraki, Japan Y. Liu KEK/JAEA, Ibaraki-Ken, Japan T. Maruta J-PARC, KEK & JAEA, Ibaraki-ken, Japan T. Miyao KEK, Ibaraki, Japan
	We used bunch shape monitors (BSMs) to measure the longitudinal bunch length of a negative hydrogen ion beam in the J-PARC linac. Because we experienced a vacuum degradation to suspend a beam operation during the BSM operations, BSMs were once dismounted for vacuum conditioning. We installed one BSM again in the beam line with additional vacuum equipment. We stared to measure the 191-MeV beam again to tune the buncher amplitude after checking a functioning BSM by comparing its results with those of a simulation. To evaluate the measurement errors with peak beam current increasing, we observed waveforms with various beam currents. Therefore, the RMS bunch length depends on the peak beam current and the bending at the pulse head grows with the peak beam current. Furthermore, to avoid the thermal stress, we compared the data taken at an off-center beam with the ones taken at an on-center beam, because a target wire will be exposed to a higher peak beam current. In this study, we introduced the peak beam current dependence of the bunch length waveforms, and an effect of on-/off-centering of the wire position. Finally, the new buncher tuning method using one BSM is discussed.
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Paper

Title

Page

Machine Stability Analysis by Pulse Based Data Archiver of the J-PARC RCS

381

N. Hayashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC RCS (Rapid-Cycling proton Synchrotron) runs with repetition rate of 25 Hz. The beam intensity of current monitors and beam loss monitors (BLM) data are archived for all pulses and they could be analyzed to study the machine stability. In addition BPM data are also recorded in regularly (2 seconds with every minutes) and particularly in case of the RCS MPS, the last several hundreds BPM data are recorded. We will report a few examples, in the case of magnet feedback problem or vacuum problem, how the BPM or BLM behaves.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB027

Bunch Length Analysis of Negative Hydrogen Ion Beam in J-PARC Linac

386

A. Miura, N. Hayashi
JAEA/J-PARC, Tokai-mura, Japan
S. Fukuoka
University of Tsukuba, Graduate School of Pure and Applied Sciences,, Tsukuba, Ibaraki, Japan
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
T. Miyao
KEK, Ibaraki, Japan

We used bunch shape monitors (BSMs) to measure the longitudinal bunch length of a negative hydrogen ion beam in the J-PARC linac. Because we experienced a vacuum degradation to suspend a beam operation during the BSM operations, BSMs were once dismounted for vacuum conditioning. We installed one BSM again in the beam line with additional vacuum equipment. We stared to measure the 191-MeV beam again to tune the buncher amplitude after checking a functioning BSM by comparing its results with those of a simulation. To evaluate the measurement errors with peak beam current increasing, we observed waveforms with various beam currents. Therefore, the RMS bunch length depends on the peak beam current and the bending at the pulse head grows with the peak beam current. Furthermore, to avoid the thermal stress, we compared the data taken at an off-center beam with the ones taken at an on-center beam, because a target wire will be exposed to a higher peak beam current. In this study, we introduced the peak beam current dependence of the bunch length waveforms, and an effect of on-/off-centering of the wire position. Finally, the new buncher tuning method using one BSM is discussed.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)