HB2014 - List of Authors (Toyama, T.)

Paper

Title

Page

Resonance Structures in the Impedance of a Ceramic Break and the Measured Results

74

Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y.H. Chin, K. Takata
KEK, Tokai, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Recently, we have developed a new theory to evaluate longitudinal and transverse impedances of any size of ceramic break sandwiched between metal chambers. The theory successfully reproduces the resonance structures in the impedance due to trapped modes inside the ceramic break. The comparisons between the theoretical and the simulation results such as ABCI and CST Studio show excellent agreements, indicating that they can be used as a good benchmark test for accuracy of simulation codes. To demonstrate the existence of such resonances, the transverse impedance of the ceramic break is measured using the wire-method. The measurement results reproduce the simulations well. The theory is particularly useful for the evaluation of the impedance of the ceramic break with titanium nitride coating.

TUO2AB04

Two-Dimensional and Wide Dynamic Range Profile Monitor Using OTR / Fluorescence Screens for Diagnosing Beam Halo of Intense Proton Beams

187

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

An instrument which can diagnose a two-dimensional beam profile of the beam core together with the beam halo in wide dynamic range has been developed in the J-PARC. The instrument consists of OTR (Ti foil of 10 μm) screen, fluorescence (Cr doped alumina) screen, an Offner type imaging system, and a camera with image intensifier. The beam core is observed with OTR and the beam halo is observed with fluorescence screen, respectively. A combination of observations of beam core and halo with these two different screens that have different sensitivities allowed us an observation in wide-dynamic range. The four fluorescence screens are set in vertical and horizontal arrangement. Both the OTR and fluorescence are focused by an Offner type optics having a very wide incident pupil makes these images. This instrument is set in the beam transport line between the rapid cycling synchrotron and the main ring. A two dimensional profile of the beam core and the halo were successfully observed in six order of magnitude at projected plane using intense 3 GeV proton beams of 1.5 x 10¹³ protons. This monitor has a big advantage for the diagnostic of beam core and halo shapes in real space.
[1] Y. Hashimoto, et al., A Development of High Sensitive Beam Profile Monitor Using Multi-Screen, Proc. IBIC2013, 338-341.

Slides TUO2AB04 [3.172 MB]

WEO2AB03

Beam Instrumentation at the 1 MW Proton Beam of J-PARC RCS

278

K. Yamamoto, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, K. Okabe, P.K. Saha, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Hashimoto, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Rapid Cycling Synchrotron(RCS) of Japan Proton Accelerator Complex(J-PARC) is providing more than 300 kW of proton beam to Material and Life science Facility(MLF) and Main Ring(MR). Last summer shutdown, a new ion source was installed to increase output power to 1 MW. In order to achieve reliable operation of 1 MW, we need to reduce beam loss as well. Beam quality of such higher output power is also important for users. We present beam monitor systems for these purposes.

Slides WEO2AB03 [3.242 MB]

THO2AB02

The Kicker Impedance and its Effect on the RCS in J-PARC

369

Y. Shobuda, P.K. Saha, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan
Y.H. Chin, Y. Irie
KEK, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Measurements demonstrate that the kicker impedance dominates along the RCS. Based on a newly developed theory, the impedance is measured by observing the beam-induced voltages at the ends of power cable of the kicker. Toward one mega-watt goal, it is essential to take advantage of tune manipulations and the space charge damping effect. A reduction scheme of the kicker impedance is proposed to pursue the ultimate goal at the RCS.

Slides THO2AB02 [9.113 MB]

FRO2AU02

Summary from Working Group F: Instrumentation and Beam Material Interactions

453

M.G. Minty
BNL, Upton, Long Island, New York, USA
R. Dölling
PSI, Villigen PSI, Switzerland
N.V. Mokhov
Fermilab, Batavia, Illinois, USA
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

This workshop on High-Intensity, High Brightness and High Power Hadron Beams, held in East Lansing, MI and hosted by Facility for Rare Isotope Beams (FRIB), included a Working Group which combined the topics of Instrumentation and Beam Material Interactions. Continuing with the HB Workshop series tradition, progress, status and future developments of hadron accelerators in these subfields were presented and discussed. Leveraging off of experiences from existing accelerators including FNAL, IFMIF, JPARC, the LHC, RHIC and the SNS, this workshop provided occasion to discuss new technical challenges for beam instrument-ation and beam material interactions as relevant for future high power hadron beam facilities both approved (e.g. FRIB, ESS) and in planning (e.g. CADS). Discussions between this and the other working groups during this workshop were quite lively as necessitated by the need to seriously address strong interdependencies (between beam dynamics, technologies, instrumentation and interaction of the beams with materials such as targets, beam dumps and collimators) in the regime of megawatt beam powers as anticipated in approved and future accelerators.

Slides FRO2AU02 [4.372 MB]

THO3AB01

Performance of Transverse Intra-Bunch Feedback System at J-PAC MR

384

Y.H. Chin, T. Obina, M. Okada, M. Tobiyama, T. Toyama
KEK, Ibaraki, Japan
K.G. Nakamura
Kyoto University, Kyoto, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

A new broadband (~100 MHz) feedback system has been developed for suppression of intra-bunch oscillations and reduction of particle losses at the J-PARC Main Ring (MR). A new BPM has been designed and fabricated, based on Linnecar’s exponential coupler stripline type, for a flatter and wider frequency response. The design and performance of the new BPM as well as preparation of a newly installed exciter and power amplifier is presented. We also report beam test results of suppression of horizontal intra-bunch oscillations at 3 GeV with the bunch length of 150-200 ns.

Slides THO3AB01 [6.245 MB]

Paper	Title	Page
MOPAB23	Resonance Structures in the Impedance of a Ceramic Break and the Measured Results	74
	Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y.H. Chin, K. Takata KEK, Tokai, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Recently, we have developed a new theory to evaluate longitudinal and transverse impedances of any size of ceramic break sandwiched between metal chambers. The theory successfully reproduces the resonance structures in the impedance due to trapped modes inside the ceramic break. The comparisons between the theoretical and the simulation results such as ABCI and CST Studio show excellent agreements, indicating that they can be used as a good benchmark test for accuracy of simulation codes. To demonstrate the existence of such resonances, the transverse impedance of the ceramic break is measured using the wire-method. The measurement results reproduce the simulations well. The theory is particularly useful for the evaluation of the impedance of the ceramic break with titanium nitride coating.

TUO2AB04	Two-Dimensional and Wide Dynamic Range Profile Monitor Using OTR / Fluorescence Screens for Diagnosing Beam Halo of Intense Proton Beams	187
	Y. Hashimoto, M. Tejima, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan A. Akino, Y. Omori, S. Otsu, H. Sakai Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan T.M. Mitsuhashi KEK, Ibaraki, Japan
	An instrument which can diagnose a two-dimensional beam profile of the beam core together with the beam halo in wide dynamic range has been developed in the J-PARC. The instrument consists of OTR (Ti foil of 10 μm) screen, fluorescence (Cr doped alumina) screen, an Offner type imaging system, and a camera with image intensifier. The beam core is observed with OTR and the beam halo is observed with fluorescence screen, respectively. A combination of observations of beam core and halo with these two different screens that have different sensitivities allowed us an observation in wide-dynamic range. The four fluorescence screens are set in vertical and horizontal arrangement. Both the OTR and fluorescence are focused by an Offner type optics having a very wide incident pupil makes these images. This instrument is set in the beam transport line between the rapid cycling synchrotron and the main ring. A two dimensional profile of the beam core and the halo were successfully observed in six order of magnitude at projected plane using intense 3 GeV proton beams of 1.5 x 10¹³ protons. This monitor has a big advantage for the diagnostic of beam core and halo shapes in real space. [1] Y. Hashimoto, et al., A Development of High Sensitive Beam Profile Monitor Using Multi-Screen, Proc. IBIC2013, 338-341.
	Slides TUO2AB04 [3.172 MB]

WEO2AB03	Beam Instrumentation at the 1 MW Proton Beam of J-PARC RCS	278
	K. Yamamoto, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, K. Okabe, P.K. Saha, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Hashimoto, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Rapid Cycling Synchrotron(RCS) of Japan Proton Accelerator Complex(J-PARC) is providing more than 300 kW of proton beam to Material and Life science Facility(MLF) and Main Ring(MR). Last summer shutdown, a new ion source was installed to increase output power to 1 MW. In order to achieve reliable operation of 1 MW, we need to reduce beam loss as well. Beam quality of such higher output power is also important for users. We present beam monitor systems for these purposes.
	Slides WEO2AB03 [3.242 MB]

THO2AB02	The Kicker Impedance and its Effect on the RCS in J-PARC	369
	Y. Shobuda, P.K. Saha, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan Y.H. Chin, Y. Irie KEK, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Measurements demonstrate that the kicker impedance dominates along the RCS. Based on a newly developed theory, the impedance is measured by observing the beam-induced voltages at the ends of power cable of the kicker. Toward one mega-watt goal, it is essential to take advantage of tune manipulations and the space charge damping effect. A reduction scheme of the kicker impedance is proposed to pursue the ultimate goal at the RCS.
	Slides THO2AB02 [9.113 MB]

FRO2AU02	Summary from Working Group F: Instrumentation and Beam Material Interactions	453
	M.G. Minty BNL, Upton, Long Island, New York, USA R. Dölling PSI, Villigen PSI, Switzerland N.V. Mokhov Fermilab, Batavia, Illinois, USA T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	This workshop on High-Intensity, High Brightness and High Power Hadron Beams, held in East Lansing, MI and hosted by Facility for Rare Isotope Beams (FRIB), included a Working Group which combined the topics of Instrumentation and Beam Material Interactions. Continuing with the HB Workshop series tradition, progress, status and future developments of hadron accelerators in these subfields were presented and discussed. Leveraging off of experiences from existing accelerators including FNAL, IFMIF, JPARC, the LHC, RHIC and the SNS, this workshop provided occasion to discuss new technical challenges for beam instrument-ation and beam material interactions as relevant for future high power hadron beam facilities both approved (e.g. FRIB, ESS) and in planning (e.g. CADS). Discussions between this and the other working groups during this workshop were quite lively as necessitated by the need to seriously address strong interdependencies (between beam dynamics, technologies, instrumentation and interaction of the beams with materials such as targets, beam dumps and collimators) in the regime of megawatt beam powers as anticipated in approved and future accelerators.
	Slides FRO2AU02 [4.372 MB]

THO3AB01	Performance of Transverse Intra-Bunch Feedback System at J-PAC MR	384
	Y.H. Chin, T. Obina, M. Okada, M. Tobiyama, T. Toyama KEK, Ibaraki, Japan K.G. Nakamura Kyoto University, Kyoto, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	A new broadband (~100 MHz) feedback system has been developed for suppression of intra-bunch oscillations and reduction of particle losses at the J-PARC Main Ring (MR). A new BPM has been designed and fabricated, based on Linnecar’s exponential coupler stripline type, for a flatter and wider frequency response. The design and performance of the new BPM as well as preparation of a newly installed exciter and power amplifier is presented. We also report beam test results of suppression of horizontal intra-bunch oscillations at 3 GeV with the bunch length of 150-200 ns.
	Slides THO3AB01 [6.245 MB]