IBIC2012 - List of Keywords (proton)

Paper	Title	Other Keywords	Page
MOIA02	Progress of Beam Instumentation in J-PARC Linac	linac, DTL, operation, laser	1
	A. Miura JAEA/J-PARC, Tokai-mura, Japan
	J-PARC, one of the high intensity proton accelerators, achieved the output power of 300 kW at the downstream rapid cycling synchrotron with a beam energy of 181 MeV and a beam current of 15 mA. When an upgrade of an ion source which can provide 50 mA and the installation of the additional acceleration cavities for the energy upgrade up to 400 MeV are completed, output power can reach 1MW. To meet with the requirements of the high intensity beam diagnostics, we prepare several measures against high intensity proton related issues. The following subjects have been reported among many subjects: development of strip-line type beam position monitors, beam current monitors, phase monitors and transverse profile monitors. And the subjects of the beam diagnostic for the energy upgraded linac including the longitudinal beam profile monitor and the developing laser based profile monitor will be mentioned. A big earthquake occurred on May 11, 2011. We successfully recovered to have commercial operation, but a partial recovery is still undergoing. Influence of the quake on the J-PARC linac is also mentioned.
	Slides MOIA02 [2.133 MB]

MOPA06	VIMOS, New Capabilities for an Optical Safety System	target, diagnostics, radiation, software	57
	K. Thomsen, J. Devlaminck PSI, Villigen PSI, Switzerland
	VIMOS is a dedicated safety system developed at the Spallation Neutron Source SINQ at the Paul Scherrer Institut, PSI, in Switzerland. VIMOS very directly monitors the correct current density distribution of the proton beam on the target by sampling the light emitted from a glowing mesh heated by the passing protons. The design has been optimized for obtaining maximum sensitivity and timely detection of beam irregularities relying on standard well-proven components. Recently it has been demonstrated that technical boundary conditions like radiation level and signal strength should allow for upgrading the system to a sensitive diagnostic device delivering quantitative and image-resolved values for the proton current density distribution on the SINQ target. By determining the temperature of the glowing mesh from the signals in two separate wavelength bands the temperature distribution over the mesh can be derived und subsequently the incident proton beam current density distribution. Work aimed at investigating the feasibility of adding these diagnostic abilities to VIMOS shows initial promising results. The status of the project and preliminary findings will be reported.

MOPA26	Performance and Upgrade of BPMs at the J-PARC MR	quadrupole, alignment, operation, bunching	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	target, optics, radiation, beam-transport	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.

MOPB68	Development of Profile Monitor System for High Intense Spallation Neutron Source	target, neutron, radiation, remote-handling	227
	S.I. Meigo, A. Akutsu, M. Futakawa, K. Ikezaki, M. Ooi, S. Sakamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	At the JSNS in J-PARC, a mercury target is employed as the neutron production target. It is well known that the damage on the mercury target is promotional to the 4th power of the peak current density of the primary proton beam on the target. For the high intense neutron source, the profile on the target is important to drive the neutron source with the continuously observation of the profile. We have developed to Multi Wire Profile Monitor System (MWPM). During beam operation, when the abnormally of the beam is found, the beam is cut out by the Machine Protection System (MPS). For the measurement of the two dimension observation on the target, we have developed the system based on the residual radiation measurement by using an imaging plate (IP), It is found that the both result by the MWPM and IP shows good agreement.

MOPB75	Real-time Beam Profile Measurement System using Fluorescent Screens	real-time, target, ion, cyclotron	246
	T. Yuyama, I. Ishibori, T. Ishizaka, S. Okumura, Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	In the TIARA AVF cyclotron facility of JAEA, we are developing an irradiation technique of a large-area uniform ion beam formed by nonlinear focusing using multipole magnets. It is indispensable to perform beam tuning and evaluation of the beam quality at the same time for efficient operation. Therefore, we developed a real-time beam profile measurement system composed of two CCD cameras, fluorescent screens, and an image analysis program based on LabVIEW. In order to measure the transverse intensity distribution of the beam through the luminance map converted from a camera image, the characteristics of fluorescent screens, DRZ (Gd2O2S:Tb) and AF995R (Al2O3:Cr), were investigated using several species of ion beams. It was found that the light yield from the DRZ-HIGH screen irradiated with 10 MeV H⁺ beam was increased linearly with the particle fluence rate from 5×10⁷ to 5×10⁸ [cm^-2･s⁻¹] and that the relative transverse intensity distribution could be obtained from the fluorescence in real time. It was also confirmed that the intensity distribution measured in this system agreed well with the relative intensity distribution obtained with a Gafchromic radiochromic film.

MOPB81	Residual Gas Ionization Profile Monitors in J-PARC Slow-extraction Beam Line	electron, extraction, radiation, vacuum	267
	Y. Sato, A. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, R. Muto, M. Naruki, S. Sawada, Y. Shirakabe, Y. Suzuki, H. Takahashi, M. Takasaki, K.H. Tanaka, A. Toyoda, H. Watanabe, Y. Yamanoi KEK, Tsukuba, Japan H. Noumi RCNP, Osaka, Japan
	Residual gas ionization profile monitors (RGIPMs) working in 1 Pa pressure have been developed for high-intensity proton beam (maximum: 50GeV-15uA) at J-PARC slow-extraction beam line. The transverse beam profiles are measured by collecting electrons produced by ionization of 1 Pa residual gas. The electrons are guided to the segmented electrode with a uniform electrostatic field applied in the gap. A uniform magnetic field is applied parallel to the electric field to reduce diffusion of electrons travelling to the electrodes. Typical spatial resolution of the RGIPMs with a 10 cm gap, a 10 V/cm electrostatic field, and a 400 gauss magnetic field at center is 0.5 mm. The collected charge is integrated during every extraction period (typically 2 second in 6 second accelerator cycle). Subtracting background distributions measured during off-beam period, profile distributions are measured clearly. The 14 RGIPMs installed in the slow-extraction beam line are working stably for the 30 GeV-0.46 uA proton beam at current maximum. In this contribution, detailed specifications and performance of the present RGIPMs will be reported.

MOPB85	Latest Results from the 4.8GHz LHC Schottky Systems	ion, injection, pick-up, experiment	279
	M. Favier, O.R. Jones CERN, Geneva, Switzerland
	This paper will present the latest results from the LHC 4.8GHz travelling wave Schottky system, summarising measurements performed during the 2011 and 2012 LHC runs. It will also describe attempts to improve the system architecture in order to make it more immune to the strong coherent lines observed with proton bunches even at these very high frequencies.

TUPB57	Extreme Light Infrastructure (ELI Beamlines) - Research and Technology with new Ultra-short Pulse Intense Laser driven Sources of Energetic Photons and Charged Particles	laser, electron, plasma, target	482
	L. Pribyl, L. Juha, G. Korn, T. Levato, B. Rus, S. Ter-Avetisyan Czech Republic Academy of Sciences, Institute of Physics, Prague, Czech Republic D. Margarone INFN/LNS, Catania, Italy S. Sebban LOA, Palaiseau, France
	Funding: Czech Science Foundation (Project No. P205/11/1165), the Czech Republic's Ministry of Education, Youth and Sports to ELI-Beamlines (CZ.1.05/1.1.00/483/02.0061) and OPVK CZ.1.07/2.3.00/20.0087). We will be giving an overview on the development of the 'ELI-Beamline facility', which will be a high-energy, repetition-rate laser pillar of the ELI (Extreme Light Infrastructure) project. It will be an international facility for both academic and applied research, slated to provide user capability since the beginning of 2016. The main purpose of the facility is the generation and applications of laser driven high-brightness X-ray sources and accelerated particles (electrons, protons and ions). The laser system will be delivering pulses with length ranging between 10 and 150 fs and will provide high-energy Petawatt and 10-PW peak powers. We will concentrate on the development of short photon wavelength (20 eV-100 keV) laser driven sources and their practical implementation. The sources are either based on direct interaction of the laser beam with a gaseous or solid target or will first accelerate electrons which then will interact with laser produced wigglers or directly injected into undulators. The main planned short pulse laser driven x-ray sources and their parameters will be presented together with requirements on the relevant beam detectors.

TUPB61	The First Experience with the LHC Beam Gas Ionisation Monitor	electron, injection, emittance, controls	489
	M. Sapinski, W. Andreazza, B. Dehning, A. Guerrero, M. Patecki, R. Versteegen CERN, Geneva, Switzerland
	The Beam Gas Ionisation Monitors (BGI) are used to continuously measure the beam size at the LHC. This paper describes the detectors and their operation and discusses the issues encountered during the commissioning. It also discusses the various calibration procedures used to correct for non-uniformity of Multi-Channel plates and to correct the beam size for effects affecting the electron trajectory after ionisation.

TUPB73	Development of a Beam Profile Monitor using Nitrogen-Molecular Jet for Intense Beams	electron, target, ion, photon	511
	Y. Hashimoto, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan T. Fujisawa, T.M. Murakami, K. Noda NIRS, Chiba-shi, Japan Y. Hori, S. Muto, K. Yoshimura KEK, Ibaraki, Japan T. Morimoto Morimoto Engineering, Iruma, Saitama, Japan D. Ohsawa Kyoto University, Radioisotope Research Center, Kyoto-shi, Japan
	Funding: This work was supported by MEXT/JSPS KAKENHI Grant Number of 24310079 (Grant-in-Aid for Scientific Research(B)). A non-destructive beam profile monitor using a sheeted jet beam of nitrogen molecular as a target has been developed for intense ion beams. The pressure of the sheeted molecular beam was 5 x 10^-4 Pa at the beam collision point. A light emitted from excited nitrogen by an ion beam collision is measured by a high sensitive camera with a radiation resistant image intensifier. Verification of such a principle was already demonstrated with low-energy ion beams[1]. In this paper, some actual designs for intense beams of the J-PARC MR will be discussed mainly as bellow, intensity upgrade of the jet beam production, configuration of the detection chamber and its apparatus placed beam collision point, and the optical system for the light detection. *[1] Y. Hashimoto, et al., Proc. of IPAC'10, Kyoto, Japan, p.987-989.

TUPB78	Flying Wire Beam Profile Monitors at the J-PARC MR	injection, timing, background, emittance	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

Other Keywords

Page

MOIA02

Progress of Beam Instumentation in J-PARC Linac

linac, DTL, operation, laser

1

A. Miura
JAEA/J-PARC, Tokai-mura, Japan

J-PARC, one of the high intensity proton accelerators, achieved the output power of 300 kW at the downstream rapid cycling synchrotron with a beam energy of 181 MeV and a beam current of 15 mA. When an upgrade of an ion source which can provide 50 mA and the installation of the additional acceleration cavities for the energy upgrade up to 400 MeV are completed, output power can reach 1MW. To meet with the requirements of the high intensity beam diagnostics, we prepare several measures against high intensity proton related issues. The following subjects have been reported among many subjects: development of strip-line type beam position monitors, beam current monitors, phase monitors and transverse profile monitors. And the subjects of the beam diagnostic for the energy upgraded linac including the longitudinal beam profile monitor and the developing laser based profile monitor will be mentioned. A big earthquake occurred on May 11, 2011. We successfully recovered to have commercial operation, but a partial recovery is still undergoing. Influence of the quake on the J-PARC linac is also mentioned.

Slides MOIA02 [2.133 MB]

MOPA06

VIMOS, New Capabilities for an Optical Safety System

target, diagnostics, radiation, software

57

K. Thomsen, J. Devlaminck
PSI, Villigen PSI, Switzerland

VIMOS is a dedicated safety system developed at the Spallation Neutron Source SINQ at the Paul Scherrer Institut, PSI, in Switzerland. VIMOS very directly monitors the correct current density distribution of the proton beam on the target by sampling the light emitted from a glowing mesh heated by the passing protons. The design has been optimized for obtaining maximum sensitivity and timely detection of beam irregularities relying on standard well-proven components. Recently it has been demonstrated that technical boundary conditions like radiation level and signal strength should allow for upgrading the system to a sensitive diagnostic device delivering quantitative and image-resolved values for the proton current density distribution on the SINQ target. By determining the temperature of the glowing mesh from the signals in two separate wavelength bands the temperature distribution over the mesh can be derived und subsequently the incident proton beam current density distribution. Work aimed at investigating the feasibility of adding these diagnostic abilities to VIMOS shows initial promising results. The status of the project and preliminary findings will be reported.

MOPA26

Performance and Upgrade of BPMs at the J-PARC MR

quadrupole, alignment, operation, bunching

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

target, optics, radiation, beam-transport

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.

MOPB68

Development of Profile Monitor System for High Intense Spallation Neutron Source

target, neutron, radiation, remote-handling

227

S.I. Meigo, A. Akutsu, M. Futakawa, K. Ikezaki, M. Ooi, S. Sakamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

At the JSNS in J-PARC, a mercury target is employed as the neutron production target. It is well known that the damage on the mercury target is promotional to the 4th power of the peak current density of the primary proton beam on the target. For the high intense neutron source, the profile on the target is important to drive the neutron source with the continuously observation of the profile. We have developed to Multi Wire Profile Monitor System (MWPM). During beam operation, when the abnormally of the beam is found, the beam is cut out by the Machine Protection System (MPS). For the measurement of the two dimension observation on the target, we have developed the system based on the residual radiation measurement by using an imaging plate (IP), It is found that the both result by the MWPM and IP shows good agreement.

MOPB75

Real-time Beam Profile Measurement System using Fluorescent Screens

real-time, target, ion, cyclotron

246

T. Yuyama, I. Ishibori, T. Ishizaka, S. Okumura, Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

In the TIARA AVF cyclotron facility of JAEA, we are developing an irradiation technique of a large-area uniform ion beam formed by nonlinear focusing using multipole magnets. It is indispensable to perform beam tuning and evaluation of the beam quality at the same time for efficient operation. Therefore, we developed a real-time beam profile measurement system composed of two CCD cameras, fluorescent screens, and an image analysis program based on LabVIEW. In order to measure the transverse intensity distribution of the beam through the luminance map converted from a camera image, the characteristics of fluorescent screens, DRZ (Gd2O2S:Tb) and AF995R (Al2O3:Cr), were investigated using several species of ion beams. It was found that the light yield from the DRZ-HIGH screen irradiated with 10 MeV H⁺ beam was increased linearly with the particle fluence rate from 5×10⁷ to 5×10⁸ [cm^-2･s⁻¹] and that the relative transverse intensity distribution could be obtained from the fluorescence in real time. It was also confirmed that the intensity distribution measured in this system agreed well with the relative intensity distribution obtained with a Gafchromic radiochromic film.

MOPB81

Residual Gas Ionization Profile Monitors in J-PARC Slow-extraction Beam Line

electron, extraction, radiation, vacuum

267

Y. Sato, A. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, R. Muto, M. Naruki, S. Sawada, Y. Shirakabe, Y. Suzuki, H. Takahashi, M. Takasaki, K.H. Tanaka, A. Toyoda, H. Watanabe, Y. Yamanoi
KEK, Tsukuba, Japan
H. Noumi
RCNP, Osaka, Japan

Residual gas ionization profile monitors (RGIPMs) working in 1 Pa pressure have been developed for high-intensity proton beam (maximum: 50GeV-15uA) at J-PARC slow-extraction beam line. The transverse beam profiles are measured by collecting electrons produced by ionization of 1 Pa residual gas. The electrons are guided to the segmented electrode with a uniform electrostatic field applied in the gap. A uniform magnetic field is applied parallel to the electric field to reduce diffusion of electrons travelling to the electrodes. Typical spatial resolution of the RGIPMs with a 10 cm gap, a 10 V/cm electrostatic field, and a 400 gauss magnetic field at center is 0.5 mm. The collected charge is integrated during every extraction period (typically 2 second in 6 second accelerator cycle). Subtracting background distributions measured during off-beam period, profile distributions are measured clearly. The 14 RGIPMs installed in the slow-extraction beam line are working stably for the 30 GeV-0.46 uA proton beam at current maximum. In this contribution, detailed specifications and performance of the present RGIPMs will be reported.

MOPB85

Latest Results from the 4.8GHz LHC Schottky Systems

ion, injection, pick-up, experiment

279

M. Favier, O.R. Jones
CERN, Geneva, Switzerland

This paper will present the latest results from the LHC 4.8GHz travelling wave Schottky system, summarising measurements performed during the 2011 and 2012 LHC runs. It will also describe attempts to improve the system architecture in order to make it more immune to the strong coherent lines observed with proton bunches even at these very high frequencies.

TUPB57

Extreme Light Infrastructure (ELI Beamlines) - Research and Technology with new Ultra-short Pulse Intense Laser driven Sources of Energetic Photons and Charged Particles

laser, electron, plasma, target

482

L. Pribyl, L. Juha, G. Korn, T. Levato, B. Rus, S. Ter-Avetisyan
Czech Republic Academy of Sciences, Institute of Physics, Prague, Czech Republic
D. Margarone
INFN/LNS, Catania, Italy
S. Sebban
LOA, Palaiseau, France

Funding: Czech Science Foundation (Project No. P205/11/1165), the Czech Republic's Ministry of Education, Youth and Sports to ELI-Beamlines (CZ.1.05/1.1.00/483/02.0061) and OPVK CZ.1.07/2.3.00/20.0087).
We will be giving an overview on the development of the 'ELI-Beamline facility', which will be a high-energy, repetition-rate laser pillar of the ELI (Extreme Light Infrastructure) project. It will be an international facility for both academic and applied research, slated to provide user capability since the beginning of 2016. The main purpose of the facility is the generation and applications of laser driven high-brightness X-ray sources and accelerated particles (electrons, protons and ions). The laser system will be delivering pulses with length ranging between 10 and 150 fs and will provide high-energy Petawatt and 10-PW peak powers. We will concentrate on the development of short photon wavelength (20 eV-100 keV) laser driven sources and their practical implementation. The sources are either based on direct interaction of the laser beam with a gaseous or solid target or will first accelerate electrons which then will interact with laser produced wigglers or directly injected into undulators. The main planned short pulse laser driven x-ray sources and their parameters will be presented together with requirements on the relevant beam detectors.

TUPB61

The First Experience with the LHC Beam Gas Ionisation Monitor

electron, injection, emittance, controls

489

M. Sapinski, W. Andreazza, B. Dehning, A. Guerrero, M. Patecki, R. Versteegen
CERN, Geneva, Switzerland

The Beam Gas Ionisation Monitors (BGI) are used to continuously measure the beam size at the LHC. This paper describes the detectors and their operation and discusses the issues encountered during the commissioning. It also discusses the various calibration procedures used to correct for non-uniformity of Multi-Channel plates and to correct the beam size for effects affecting the electron trajectory after ionisation.

TUPB73

Development of a Beam Profile Monitor using Nitrogen-Molecular Jet for Intense Beams

electron, target, ion, photon

511

Y. Hashimoto, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
T. Fujisawa, T.M. Murakami, K. Noda
NIRS, Chiba-shi, Japan
Y. Hori, S. Muto, K. Yoshimura
KEK, Ibaraki, Japan
T. Morimoto
Morimoto Engineering, Iruma, Saitama, Japan
D. Ohsawa
Kyoto University, Radioisotope Research Center, Kyoto-shi, Japan

Funding: This work was supported by MEXT/JSPS KAKENHI Grant Number of 24310079 (Grant-in-Aid for Scientific Research(B)).
A non-destructive beam profile monitor using a sheeted jet beam of nitrogen molecular as a target has been developed for intense ion beams. The pressure of the sheeted molecular beam was 5 x 10^-4 Pa at the beam collision point. A light emitted from excited nitrogen by an ion beam collision is measured by a high sensitive camera with a radiation resistant image intensifier. Verification of such a principle was already demonstrated with low-energy ion beams[1]. In this paper, some actual designs for intense beams of the J-PARC MR will be discussed mainly as bellow, intensity upgrade of the jet beam production, configuration of the detection chamber and its apparatus placed beam collision point, and the optical system for the light detection.
*[1] Y. Hashimoto, et al., Proc. of IPAC'10, Kyoto, Japan, p.987-989.

TUPB78

Flying Wire Beam Profile Monitors at the J-PARC MR

injection, timing, background, emittance

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.