IBIC2012 - List of Authors (Tejima, M.)

Paper

Title

Page

Beam Instrumentation for the SuperKEKB Rings

6

H. Fukuma, A. Arinaga, J.W. Flanagan, H. Ikeda, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama
KEK, Ibaraki, Japan
G. Bonvicini, H. Farhat, R.S. Gillard
Wayne State University, USA
G.S. Varner
University of Hawaii, Honolulu, HI, USA

The electron-positron collider KEKB B-factory is currently being upgraded to SuperKEKB. The design luminosity of 8 x 10³⁵ /cm²/s will be achieved using beams with low emittance of several nm and doubling beam currents to 2.6 A in the electron ring (HER) and 3.6 A in the positron ring (LER). A beam position monitor (BPM) system of HER and LER will be equipped with super-heterodyne detectors, turn by turn log ratio detectors with fast gates to measure optics parameters during collision operation and detectors of BPMs near the collision point (IP) for orbit feedback to maintain stable collision. New X-ray beam profile monitors based on the coded aperture method will be installed aiming at bunch by bunch measurement of the beam profile. A large angle beamstrahlung monitor detecting polarization of the synchrotron radiation generated by beam-beam interaction will be installed near IP to obtain information about the beam-beam geometry. The bunch by bunch feedback system will be upgraded using low noise frontend electronics and new 12 bits iGp digital filters. An overview of beam instrumentation of SuperKEKB rings will be given in this paper.

Slides MOCB01 [8.073 MB]

MOPA26

Performance and Upgrade of BPMs at the J-PARC MR

107

T. Toyama, Y. Hashimoto
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Hanamura
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan
M. Okada, M. Tejima
KEK, Ibaraki, Japan

Since recovery from the great earthquake 2011.3.11, proton beam, more than 10¹⁴ ppp, is accelerated up to 30 GeV at the J-PARC MR. The BPMs were originally designed with the external capacitors. The aim was to improve the position response in wider frequencies and to get an adequate output voltage at the design intensity, 4x10¹³ ppb. It was modified, however, not to have the capacitors. Therefore we have sufficient signal intensity from low intensity beams of the initial beam commissioning, but too large from the design intensity beam. The processing circuits (BPMC) have to accommodate those output signals from high intensity beams. We are adding the attenuator-LPFs just before the BPMC. This paper will describe these additional attenuator-LPFs. In connection with the MR collimator upgrade, some BPMs are re-allocated. This process is also reported.

MOPB67

Development of Offner Relay Optical System for OTR Monitor at 3-50 Beam Transport Line of J-PARC

222

M. Tejima, T.M. Mitsuhashi
KEK, Ibaraki, Japan
Y. Hashimoto, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
S. Otsu
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan

An extremely wide aperture relay optical system based on Offner system has been designed and constracted for OTR monitor at 3-50 beam transport line of J-PARC. Diagnostics for beam profile and halo are very important to optimize injection beam from RCS to MR in J-PARC. For this purpose, an OTR monitor is planed to install for an observation of image of the beam and halo after the beam collimators. Since opening of OTR is very wide due to small Gamma; 3.2, extremely wide aperture (500mrad) optics will necessary to extract OTR from file target. We designed Offner type relay optics for the effective extraction of OTR having F=0.83. The clear aperture will cover 100 x 100mm aria on the target screen. Results of optical testing and design of OTR monitor will present in this paper.

TUPB78

Flying Wire Beam Profile Monitors at the J-PARC MR

527

S. Igarashi, D.A. Arakawa, Y. Hashimoto, M. Tejima, T. Toyama
KEK, Ibaraki, Japan
K. Hanamura
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan

Transverse beam profiles have been measured using flying wire monitors at the main ring of the Japan Proton Accelerator Research Complex. The wire target should be thin and the wire scan has to be fast for the precise profile measurement. Otherwise the beam distribution would be disturbed and the measured profile would not be accurate. We use carbon fibers of 7 μm in diameter and the scan speed of 10 m/s. The wire is attached with an aluminum flame of 140 mm of the rotation radius and rotated with a DC servomotor. A potentiometer is attached to the wire flame and the angle readout is used for the feedback of the servomotor and the wire position measurement. The secondary particles from the beam-wire scattering are measured with a scintillation counter. Beam profiles are reconstructed by making the scatter plot of the scintillator signal and wire position. Both horizontal and vertical flying wire monitors have been used for the beam commissioning. We have successfully measured the beam profile of up to 1.2×10¹³ protons per bunch.

Paper	Title	Page
MOCB01	Beam Instrumentation for the SuperKEKB Rings	6
	H. Fukuma, A. Arinaga, J.W. Flanagan, H. Ikeda, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama KEK, Ibaraki, Japan G. Bonvicini, H. Farhat, R.S. Gillard Wayne State University, USA G.S. Varner University of Hawaii, Honolulu, HI, USA
	The electron-positron collider KEKB B-factory is currently being upgraded to SuperKEKB. The design luminosity of 8 x 10³⁵ /cm²/s will be achieved using beams with low emittance of several nm and doubling beam currents to 2.6 A in the electron ring (HER) and 3.6 A in the positron ring (LER). A beam position monitor (BPM) system of HER and LER will be equipped with super-heterodyne detectors, turn by turn log ratio detectors with fast gates to measure optics parameters during collision operation and detectors of BPMs near the collision point (IP) for orbit feedback to maintain stable collision. New X-ray beam profile monitors based on the coded aperture method will be installed aiming at bunch by bunch measurement of the beam profile. A large angle beamstrahlung monitor detecting polarization of the synchrotron radiation generated by beam-beam interaction will be installed near IP to obtain information about the beam-beam geometry. The bunch by bunch feedback system will be upgraded using low noise frontend electronics and new 12 bits iGp digital filters. An overview of beam instrumentation of SuperKEKB rings will be given in this paper.
	Slides MOCB01 [8.073 MB]

MOPA26	Performance and Upgrade of BPMs at the J-PARC MR	107
	T. Toyama, Y. Hashimoto J-PARC, KEK & JAEA, Ibaraki-ken, Japan K. Hanamura Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan M. Okada, M. Tejima KEK, Ibaraki, Japan
	Since recovery from the great earthquake 2011.3.11, proton beam, more than 10¹⁴ ppp, is accelerated up to 30 GeV at the J-PARC MR. The BPMs were originally designed with the external capacitors. The aim was to improve the position response in wider frequencies and to get an adequate output voltage at the design intensity, 4x10¹³ ppb. It was modified, however, not to have the capacitors. Therefore we have sufficient signal intensity from low intensity beams of the initial beam commissioning, but too large from the design intensity beam. The processing circuits (BPMC) have to accommodate those output signals from high intensity beams. We are adding the attenuator-LPFs just before the BPMC. This paper will describe these additional attenuator-LPFs. In connection with the MR collimator upgrade, some BPMs are re-allocated. This process is also reported.

MOPB67	Development of Offner Relay Optical System for OTR Monitor at 3-50 Beam Transport Line of J-PARC	222
	M. Tejima, T.M. Mitsuhashi KEK, Ibaraki, Japan Y. Hashimoto, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan S. Otsu Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
	An extremely wide aperture relay optical system based on Offner system has been designed and constracted for OTR monitor at 3-50 beam transport line of J-PARC. Diagnostics for beam profile and halo are very important to optimize injection beam from RCS to MR in J-PARC. For this purpose, an OTR monitor is planed to install for an observation of image of the beam and halo after the beam collimators. Since opening of OTR is very wide due to small Gamma; 3.2, extremely wide aperture (500mrad) optics will necessary to extract OTR from file target. We designed Offner type relay optics for the effective extraction of OTR having F=0.83. The clear aperture will cover 100 x 100mm aria on the target screen. Results of optical testing and design of OTR monitor will present in this paper.

TUPB78	Flying Wire Beam Profile Monitors at the J-PARC MR	527
	S. Igarashi, D.A. Arakawa, Y. Hashimoto, M. Tejima, T. Toyama KEK, Ibaraki, Japan K. Hanamura Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
	Transverse beam profiles have been measured using flying wire monitors at the main ring of the Japan Proton Accelerator Research Complex. The wire target should be thin and the wire scan has to be fast for the precise profile measurement. Otherwise the beam distribution would be disturbed and the measured profile would not be accurate. We use carbon fibers of 7 μm in diameter and the scan speed of 10 m/s. The wire is attached with an aluminum flame of 140 mm of the rotation radius and rotated with a DC servomotor. A potentiometer is attached to the wire flame and the angle readout is used for the feedback of the servomotor and the wire position measurement. The secondary particles from the beam-wire scattering are measured with a scintillation counter. Beam profiles are reconstructed by making the scatter plot of the scintillator signal and wire position. Both horizontal and vertical flying wire monitors have been used for the beam commissioning. We have successfully measured the beam profile of up to 1.2×10¹³ protons per bunch.