IBIC2016 - List of Authors (Miura, A.)

Paper	Title	Page
MOPG43	Beam Tuning for Longitudinal Profile at J-PARC Linac	150
	A. Miura JAEA/J-PARC, Tokai-mura, Japan Y. Liu, T. Maruta KEK/JAEA, Ibaraki-Ken, Japan T. Miyao KEK, Ibaraki, Japan
	Using bunch shape monitors (BSMs), we measured the longitudinal bunch lengths of negative hydrogen ion beams in the J-PARC linac. A BSM was installed between two linacs, separate-type drift tube linac (SDTL) and an annular-ring-coupled structure linac (ACS), having acceleration frequencies of 324 and 972 MHz, respectively. We used radio-frequency amplitude modulation of bunches in the beam transport between the SDTL and ACS to minimize emittance growth and beam loss. We conducted amplitude scanning and compared the results with the twiss-parameters obtained from the transverse profiles. In this paper, we discuss the results of amplitude tuning of the buncher cavity at the point of beam loss and emittance. We also discuss the measurement results for various equipartitioning settings of quadrupole magnets.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG43
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TUPG21	Beam-Loss Monitoring Signals of Interlocked Events at the J-PARC Linac	368
	N. Hayashi, Y. Kato, A. Miura JAEA/J-PARC, Tokai-mura, Japan K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan
	It is important to understand why the beam gets lost during normal operation. If RF cavity gets interlocked due to its failure, it is understandable. But it is still useful to study its detail mechanism and which beam loss monitor (BLM) receives higher loss or it is more sensitive in order to reduce a numbers of interlocked events and stabilize the accelerator operation in future. The J-PARC Linac BLM has a simple data recorder system consists of multi-oscilloscopes. Although its functionality is limited, it can record events when an interlock is triggered. Particular interest is the events associate with only BLM MPS (Machine-Protection-System). They may reveal hidden problems in the accelerator.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG21
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WEPG45	Present Status of the Laser Charge Exchange Test Using the 3-MeV Linac in J-PARC	736
	H. Takei, E. Chishiro, K. Hirano, Y. Kondo, S.I. Meigo, A. Miura, T. Morishita, H. Oguri, K. Tsutsumi JAEA/J-PARC, Tokai-mura, Japan
	The accelerator-driven system (ADS) is discussed as one of the efficient device to transmute long-lived nuclides. For the efficient transmutation of the minor actinide (MA), precise prediction of neutronic performance of ADS is indispensable. The Transmutation Physics Experimental Facility (TEF-P) aimed at obtaining experimental data for the accuracy improvement of neutronics evaluation of MA-loaded ADS. The critical assembly installed in TEF-P operates below 500 watt to prevent the excessive radio activation of assembly. For the separation of low power beam from J-PARC intense proton accelerator, the meticulous low power beam extraction method from high power proton beam is required. The laser charge exchange method (LCE) is originally developed to measure the proton beam profile and can be applied to the beam separation device for TEF-P. The LCE device consists of bright YAG-laser and laser transport system with beam position controllers. We performed the stability tests for laser power and position of exposure by no proton beam condition. The further LCE tests using negative 3-MeV proton linac in J-PARC will be conducted. In this paper, present status of LCE tests is presented.
	Poster WEPG45 [16.240 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG45
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THAL03	Multi-Laser-Wire Diagnostic for the Beam Profile Measurement of a Negative Hydrogen Ion Beam in the J-PARC LINAC	856
	A. Miura, K. Okabe, M. Yoshimoto JAEA/J-PARC, Tokai-mura, Japan I. Yamane KEK, Ibaraki, Japan
	In the J-PARC linac, the negative hydrogen ion beam is acceralated to be 400 MeV. Repitition rate will be increased to be from 25 Hz to 50 Hz. The half of 400 MeV beams are injected to the downstream scynchlotoron (RCS) and the other half will be transported to the planned experimental laboratory of the accelerator driven transmutation facility. One of the important issues for the high-current and high-brilliance accelerators is to understand the beam dynamics. The wire scanner monitor is reliably operated in many accelerator facilities around the world. Because the heat loading on a wire is getting increaced in high-current beam tuning, we focused to use a laser wire system. Ionization potential of the negative hydrogen ion is 0.75 eV and one electron is easily detached by a laser beam whose wavelength is adjusted by the Doppler-shift to a large cross-section point. In addition, we propose to use a new multi-laser-wire system. In the new system, we use a pair of concave millors with different diameters to make multi-paths of laser beam, and the beam waists of the laser paths are aligned in principle. In the paper, we propose the multi-laser-wire system and its application.
	Slides THAL03 [1.861 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-THAL03
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Paper

Title

Page

Beam Tuning for Longitudinal Profile at J-PARC Linac

150

A. Miura
JAEA/J-PARC, Tokai-mura, Japan
Y. Liu, T. Maruta
KEK/JAEA, Ibaraki-Ken, Japan
T. Miyao
KEK, Ibaraki, Japan

Using bunch shape monitors (BSMs), we measured the longitudinal bunch lengths of negative hydrogen ion beams in the J-PARC linac. A BSM was installed between two linacs, separate-type drift tube linac (SDTL) and an annular-ring-coupled structure linac (ACS), having acceleration frequencies of 324 and 972 MHz, respectively. We used radio-frequency amplitude modulation of bunches in the beam transport between the SDTL and ACS to minimize emittance growth and beam loss. We conducted amplitude scanning and compared the results with the twiss-parameters obtained from the transverse profiles. In this paper, we discuss the results of amplitude tuning of the buncher cavity at the point of beam loss and emittance. We also discuss the measurement results for various equipartitioning settings of quadrupole magnets.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG43

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TUPG21

Beam-Loss Monitoring Signals of Interlocked Events at the J-PARC Linac

368

N. Hayashi, Y. Kato, A. Miura
JAEA/J-PARC, Tokai-mura, Japan
K. Futatsukawa, T. Miyao
KEK, Ibaraki, Japan

It is important to understand why the beam gets lost during normal operation. If RF cavity gets interlocked due to its failure, it is understandable. But it is still useful to study its detail mechanism and which beam loss monitor (BLM) receives higher loss or it is more sensitive in order to reduce a numbers of interlocked events and stabilize the accelerator operation in future. The J-PARC Linac BLM has a simple data recorder system consists of multi-oscilloscopes. Although its functionality is limited, it can record events when an interlock is triggered. Particular interest is the events associate with only BLM MPS (Machine-Protection-System). They may reveal hidden problems in the accelerator.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG21

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WEPG45

Present Status of the Laser Charge Exchange Test Using the 3-MeV Linac in J-PARC

736

H. Takei, E. Chishiro, K. Hirano, Y. Kondo, S.I. Meigo, A. Miura, T. Morishita, H. Oguri, K. Tsutsumi
JAEA/J-PARC, Tokai-mura, Japan

The accelerator-driven system (ADS) is discussed as one of the efficient device to transmute long-lived nuclides. For the efficient transmutation of the minor actinide (MA), precise prediction of neutronic performance of ADS is indispensable. The Transmutation Physics Experimental Facility (TEF-P) aimed at obtaining experimental data for the accuracy improvement of neutronics evaluation of MA-loaded ADS. The critical assembly installed in TEF-P operates below 500 watt to prevent the excessive radio activation of assembly. For the separation of low power beam from J-PARC intense proton accelerator, the meticulous low power beam extraction method from high power proton beam is required. The laser charge exchange method (LCE) is originally developed to measure the proton beam profile and can be applied to the beam separation device for TEF-P. The LCE device consists of bright YAG-laser and laser transport system with beam position controllers. We performed the stability tests for laser power and position of exposure by no proton beam condition. The further LCE tests using negative 3-MeV proton linac in J-PARC will be conducted. In this paper, present status of LCE tests is presented.

Poster WEPG45 [16.240 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG45

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THAL03

Multi-Laser-Wire Diagnostic for the Beam Profile Measurement of a Negative Hydrogen Ion Beam in the J-PARC LINAC

856

A. Miura, K. Okabe, M. Yoshimoto
JAEA/J-PARC, Tokai-mura, Japan
I. Yamane
KEK, Ibaraki, Japan

In the J-PARC linac, the negative hydrogen ion beam is acceralated to be 400 MeV. Repitition rate will be increased to be from 25 Hz to 50 Hz. The half of 400 MeV beams are injected to the downstream scynchlotoron (RCS) and the other half will be transported to the planned experimental laboratory of the accelerator driven transmutation facility. One of the important issues for the high-current and high-brilliance accelerators is to understand the beam dynamics. The wire scanner monitor is reliably operated in many accelerator facilities around the world. Because the heat loading on a wire is getting increaced in high-current beam tuning, we focused to use a laser wire system. Ionization potential of the negative hydrogen ion is 0.75 eV and one electron is easily detached by a laser beam whose wavelength is adjusted by the Doppler-shift to a large cross-section point. In addition, we propose to use a new multi-laser-wire system. In the new system, we use a pair of concave millors with different diameters to make multi-paths of laser beam, and the beam waists of the laser paths are aligned in principle. In the paper, we propose the multi-laser-wire system and its application.

Slides THAL03 [1.861 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-THAL03

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