IPAC2014 - List of Authors (Fujita, T.)

Paper	Title	Page
MOPRO080	Fast Beam Orbit Monitoring System during Beam Abort at SPring-8 Storage Ring	274
	T. Fujita, T. Masuda, S. Sasaki JASRI/SPring-8, Hyogo, Japan H. Sumitomo SES, Hyogo-pref., Japan
	SPring-8 is a 3rd generation light source which has been operated stably. During user operation, an interlock system which turns off the RF acceleration signal if the beam orbit at insertion devices exceed a window is in operation. Beam abort events due to the interlock system have occurred as a rare event at SPring-8. Though in most cases we find trouble in accelerator devices as the source of the beam orbit shift, sometimes we cannot find any evidence after the beam abort. In order to identify the sources of such aborts, we have developed a system which observe beam orbit along the storage ring during beam abort. The system was realized by modification of the digital part of the existing COD measurement system. Every 1 ms, the system measures beam position at all BPMs with the position resolution of 1 micron or less. This system enabled us to identify the source when a beam abort due to an orbit shift with a time constant of longer than a few milliseconds. Furthermore, this system is applicable to survey sources of beam orbit fluctuations during stable operation. In this proceeding, we describe the system, beam orbit data during beam abort and source analysis.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO080
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRO081	Resonance Frequency Feedback System for a Precise Magnet Alignment using Multi-vibrating Wires	277
	K. Fukami, N. Azumi, T. Fujita, T. Honiden, H. Kimura, T. Nakanishi, Y. Okayasu, C. Zhang JASRI/SPring-8, Hyogo-ken, Japan K. Kajimoto, T. Watanabe SES, Hyogo-pref., Japan S. Matsui RIKEN/SPring-8, Hyogo, Japan
	An ultimate storage ring (USR) is being designed at synchrotron radiation facilities in the world. USR can generate theoretically minimum synchrotron radiation because emittance of the USR is less than diffraction limit of the radiation. The USR requires high alignment precision of micro-meter order. A vibrating wire method (VWM) has widely been used for such a high precision alignment. An error field of multi-pole magnet is estimated by detecting a vibration of a single wire excited with AC current. The wire position, where no vibration is excited, is defined as the magnetic center. The applied frequency is kept on a resonant frequency, which may drift due to temperature change etc. during the measurement. To trace the resonant frequency at all times, we developed a frequency feedback system. It is necessary to trace the resonance, even when the wire is set in the vicinity of the magnetic center where the magnetic field is nearly zero. Here we propose to install one or two additional wires parallel to the original wire. The additional wires off the center can detect the vibration frequency with enough S/N ratio. We discuss the effectiveness of it for quick and reliable alignment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO081
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Fast Beam Orbit Monitoring System during Beam Abort at SPring-8 Storage Ring

274

T. Fujita, T. Masuda, S. Sasaki
JASRI/SPring-8, Hyogo, Japan
H. Sumitomo
SES, Hyogo-pref., Japan

SPring-8 is a 3rd generation light source which has been operated stably. During user operation, an interlock system which turns off the RF acceleration signal if the beam orbit at insertion devices exceed a window is in operation. Beam abort events due to the interlock system have occurred as a rare event at SPring-8. Though in most cases we find trouble in accelerator devices as the source of the beam orbit shift, sometimes we cannot find any evidence after the beam abort. In order to identify the sources of such aborts, we have developed a system which observe beam orbit along the storage ring during beam abort. The system was realized by modification of the digital part of the existing COD measurement system. Every 1 ms, the system measures beam position at all BPMs with the position resolution of 1 micron or less. This system enabled us to identify the source when a beam abort due to an orbit shift with a time constant of longer than a few milliseconds. Furthermore, this system is applicable to survey sources of beam orbit fluctuations during stable operation. In this proceeding, we describe the system, beam orbit data during beam abort and source analysis.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO080

Export •

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

MOPRO081

Resonance Frequency Feedback System for a Precise Magnet Alignment using Multi-vibrating Wires

277

K. Fukami, N. Azumi, T. Fujita, T. Honiden, H. Kimura, T. Nakanishi, Y. Okayasu, C. Zhang
JASRI/SPring-8, Hyogo-ken, Japan
K. Kajimoto, T. Watanabe
SES, Hyogo-pref., Japan
S. Matsui
RIKEN/SPring-8, Hyogo, Japan

An ultimate storage ring (USR) is being designed at synchrotron radiation facilities in the world. USR can generate theoretically minimum synchrotron radiation because emittance of the USR is less than diffraction limit of the radiation. The USR requires high alignment precision of micro-meter order. A vibrating wire method (VWM) has widely been used for such a high precision alignment. An error field of multi-pole magnet is estimated by detecting a vibration of a single wire excited with AC current. The wire position, where no vibration is excited, is defined as the magnetic center. The applied frequency is kept on a resonant frequency, which may drift due to temperature change etc. during the measurement. To trace the resonant frequency at all times, we developed a frequency feedback system. It is necessary to trace the resonance, even when the wire is set in the vicinity of the magnetic center where the magnetic field is nearly zero. Here we propose to install one or two additional wires parallel to the original wire. The additional wires off the center can detect the vibration frequency with enough S/N ratio. We discuss the effectiveness of it for quick and reliable alignment.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO081

Export •

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