IPAC2013 - List of Authors (Iwashita, Y.)

Paper

Title

Page

Multi-strip Current Monitor for Pulsed Laser Plasma Diagnostics

538

Y. Fuwa, Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
M. Okamura
BNL, Upton, Long Island, New York, USA

A compact position-sensitive beam instrumentation devise is under development. The beam detection area of this devise is composed of multi-strip electrodes and scanned by multiplexers, which reduces the number of read-out lines and feed-through connectors. Combined with an electrostatic deflector and ToF information, this monitor can discriminate charge to mass ratios of particles. A prototype of this monitor is fabricated for measurement of ion distribution and charge state in laser induced plasma. This model has fifteen strip electrodes and the multiplexed signal and the clock signal are read out through two coaxial cables. Thus, only three cables are needed including a +5V power supply line. The test result will be presented.

TUPEA012

Rebunching Ultracold Neutrons by Magnetic Deceleration for the neutron EDM experiment at J-PARC

1187

S. Imajo
Kyoto University, Kyoto, Japan
Y. Arimoto
KEK, Ibaraki, Japan
P.W. Geltenbort
ILL, Grenoble, France
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
M. Kitaguchi
Kyoto University, Research Reactor Institute, Osaka, Japan
Y. Seki
RIKEN Nishina Center, Wako, Japan
H.M. Shimizu
Nagoya University, Nagoya, Japan
T. Yoshioka
Kyushu University, Fukuoka, Japan

Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. Neutron have a magnetic dipole moment, and hence their kinetic energies vary depending on their spin in magnetic fields. Their kinetic energies are restored when they get out from the magnetic field area if their spin did not flip. A spin flip can be triggered by applying an RF field whose frequency coincides with the spin precession frequency of a neutron in this magnetic field. This allows to tune the kinetic energy of neutrons. This method can be used to rebunch a pulsed beam of neutrons to a storage bottle that can store UCN. By open and close the storage bottle synchronously with the rebuncher, high UCN densities can be achieved for precision measurements of neutron properties such as the Electric Dipole Moment. The method and experimental setup are described in detail and the results of a recent first test experiments are presented.

WEPWO014

Rf Field-Attenuation Formulae for the Multilayer Coating Model

2343

T. Kubo, T. Saeki
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan

Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.

WEPWO015

Electron Beam Welding for High Gradient Superconducting Cavity

2346

T. Kubo, Y. Ajima, H. Hayano, H. Inoue, S. Kato, T. Saeki, M. Sawabe, K. Umemori, Y. Watanabe, S. Yamaguchi, M. Yamanaka
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
T. Nagata
ULVAC, Inc., Tsukuba, Japan

Relations between electron beam welding parameters and appearances of weld beads are studied. It was found that a beam generator position and a welding direction affect a geometry of weld bead dramatically. Carbon including contaminants found after the chemistry are also commented.

WEPWO017

Efforts on Nondestructive Inspections for SC Cavities

2352

Y. Iwashita, Y. Fuwa, M. Hashida, S. Sakabe, S. Tokita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan
K. Otani
INRS-EMT, Varennes (Québec), Canada

The high resolution camera, so-called Kyoto Camera, inspecting the Sc cavity inner surface showed the importance of nondestructive inspections to improve yield in production of high performance SC Cavities. Further efforts have been continued for the inspection and the high resolution T-map, X-map and eddy current scanner have been developed. A radiography to detect small voids inside the Nb EBW seam with the target resolution of 0.1 mm is under investigation. We have carried out radiography tests with X-rays induced from an ultra short pulse intense laser.

WEPFI024

Anisotropic Ferrite Magnet Focusing System for Klystrons

2756

Y. Fuwa, H. Ikeda, Y. Iwashita, R. Kitahara, Y. Nasu, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
S. Fukuda, T. Matsumoto, S. Michizono
KEK, Ibaraki, Japan

The permanent magnet beam focusing for klystrons can eliminate the solenoid coil with the water cooling system and the power supply that consumes electricity. Hence the failure rate and the operating cost of RF systems should decrease. This feature is suitable for a large facility that requires a lot of klystrons such as ILC. Since the required magnetic field for klystron beam is moderate, inexpensive anisotropic ferrite magnets can be applied. The test model is fabricated for a 1.3 GHz klystron whose output power is 800 kW. Each magnet block in the model is movable for magnetic field adjustment and the iron yoke in the oil tank improves magnetic field distribution around cathode area. The result of a klystron power test will be presented.

THOBB203

Study on Fabrication of Superconducting RF 9-cell Cavity for ILC at KEK

3132

T. Saeki, Y. Ajima, K. Enami, H. Hayano, H. Inoue, E. Kako, S. Kato, S. Koike, T. Kubo, S. Noguchi, M. Satoh, M. Sawabe, T. Shishido, A. Terashima, N. Toge, K. Ueno, K. Umemori, K. Watanabe, Y. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, M. Yamanaka, K. Yokoya
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
N. Kawabata, H. Nakamura, K. Nohara, M. Shinohara
SPS, Funabashi-shi, Japan
F. Yasuda
The University of Tokyo, Institute of Physics, Tokyo, Japan

We constructed a new facility for the fabrication of superconducting RF cavity at KEK from 2009 to 2011. In the facility, we have installed a deep-drawing machine, a half-cell trimming machine, an electron-beam welding machine, and a chemical etching room in one place. We started the study on the fabrication of 9-cell cavity for International Linear Collier (ILC) from 2009 using this facility. The study is focusing on the cost reduction with keeping high performance of cavity, and the goal is the establishment of mass-production procedure for ILC. This article reports the current status of the studies in CFF.

Slides THOBB203 [3.983 MB]

THPFI017

Development of Harmonic Field Measurement System with Higher Resolution ADC

3330

R. Kitahara, Y. Fuwa, Y. Iwashita, Y. Nasu
Kyoto ICR, Uji, Kyoto, Japan

Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally.

Paper	Title	Page
MOPME029	Multi-strip Current Monitor for Pulsed Laser Plasma Diagnostics	538
	Y. Fuwa, Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan M. Okamura BNL, Upton, Long Island, New York, USA
	A compact position-sensitive beam instrumentation devise is under development. The beam detection area of this devise is composed of multi-strip electrodes and scanned by multiplexers, which reduces the number of read-out lines and feed-through connectors. Combined with an electrostatic deflector and ToF information, this monitor can discriminate charge to mass ratios of particles. A prototype of this monitor is fabricated for measurement of ion distribution and charge state in laser induced plasma. This model has fifteen strip electrodes and the multiplexed signal and the clock signal are read out through two coaxial cables. Thus, only three cables are needed including a +5V power supply line. The test result will be presented.

TUPEA012	Rebunching Ultracold Neutrons by Magnetic Deceleration for the neutron EDM experiment at J-PARC	1187
	S. Imajo Kyoto University, Kyoto, Japan Y. Arimoto KEK, Ibaraki, Japan P.W. Geltenbort ILL, Grenoble, France Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan M. Kitaguchi Kyoto University, Research Reactor Institute, Osaka, Japan Y. Seki RIKEN Nishina Center, Wako, Japan H.M. Shimizu Nagoya University, Nagoya, Japan T. Yoshioka Kyushu University, Fukuoka, Japan
	Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. Neutron have a magnetic dipole moment, and hence their kinetic energies vary depending on their spin in magnetic fields. Their kinetic energies are restored when they get out from the magnetic field area if their spin did not flip. A spin flip can be triggered by applying an RF field whose frequency coincides with the spin precession frequency of a neutron in this magnetic field. This allows to tune the kinetic energy of neutrons. This method can be used to rebunch a pulsed beam of neutrons to a storage bottle that can store UCN. By open and close the storage bottle synchronously with the rebuncher, high UCN densities can be achieved for precision measurements of neutron properties such as the Electric Dipole Moment. The method and experimental setup are described in detail and the results of a recent first test experiments are presented.

WEPWO014	Rf Field-Attenuation Formulae for the Multilayer Coating Model	2343
	T. Kubo, T. Saeki KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan
	Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.

WEPWO015	Electron Beam Welding for High Gradient Superconducting Cavity	2346
	T. Kubo, Y. Ajima, H. Hayano, H. Inoue, S. Kato, T. Saeki, M. Sawabe, K. Umemori, Y. Watanabe, S. Yamaguchi, M. Yamanaka KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan T. Nagata ULVAC, Inc., Tsukuba, Japan
	Relations between electron beam welding parameters and appearances of weld beads are studied. It was found that a beam generator position and a welding direction affect a geometry of weld bead dramatically. Carbon including contaminants found after the chemistry are also commented.

WEPWO017	Efforts on Nondestructive Inspections for SC Cavities	2352
	Y. Iwashita, Y. Fuwa, M. Hashida, S. Sakabe, S. Tokita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan K. Otani INRS-EMT, Varennes (Québec), Canada
	The high resolution camera, so-called Kyoto Camera, inspecting the Sc cavity inner surface showed the importance of nondestructive inspections to improve yield in production of high performance SC Cavities. Further efforts have been continued for the inspection and the high resolution T-map, X-map and eddy current scanner have been developed. A radiography to detect small voids inside the Nb EBW seam with the target resolution of 0.1 mm is under investigation. We have carried out radiography tests with X-rays induced from an ultra short pulse intense laser.

WEPFI024	Anisotropic Ferrite Magnet Focusing System for Klystrons	2756
	Y. Fuwa, H. Ikeda, Y. Iwashita, R. Kitahara, Y. Nasu, H. Tongu Kyoto ICR, Uji, Kyoto, Japan S. Fukuda, T. Matsumoto, S. Michizono KEK, Ibaraki, Japan
	The permanent magnet beam focusing for klystrons can eliminate the solenoid coil with the water cooling system and the power supply that consumes electricity. Hence the failure rate and the operating cost of RF systems should decrease. This feature is suitable for a large facility that requires a lot of klystrons such as ILC. Since the required magnetic field for klystron beam is moderate, inexpensive anisotropic ferrite magnets can be applied. The test model is fabricated for a 1.3 GHz klystron whose output power is 800 kW. Each magnet block in the model is movable for magnetic field adjustment and the iron yoke in the oil tank improves magnetic field distribution around cathode area. The result of a klystron power test will be presented.

THOBB203	Study on Fabrication of Superconducting RF 9-cell Cavity for ILC at KEK	3132
	T. Saeki, Y. Ajima, K. Enami, H. Hayano, H. Inoue, E. Kako, S. Kato, S. Koike, T. Kubo, S. Noguchi, M. Satoh, M. Sawabe, T. Shishido, A. Terashima, N. Toge, K. Ueno, K. Umemori, K. Watanabe, Y. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, M. Yamanaka, K. Yokoya KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan N. Kawabata, H. Nakamura, K. Nohara, M. Shinohara SPS, Funabashi-shi, Japan F. Yasuda The University of Tokyo, Institute of Physics, Tokyo, Japan
	We constructed a new facility for the fabrication of superconducting RF cavity at KEK from 2009 to 2011. In the facility, we have installed a deep-drawing machine, a half-cell trimming machine, an electron-beam welding machine, and a chemical etching room in one place. We started the study on the fabrication of 9-cell cavity for International Linear Collier (ILC) from 2009 using this facility. The study is focusing on the cost reduction with keeping high performance of cavity, and the goal is the establishment of mass-production procedure for ILC. This article reports the current status of the studies in CFF.
	Slides THOBB203 [3.983 MB]

THPFI017	Development of Harmonic Field Measurement System with Higher Resolution ADC	3330
	R. Kitahara, Y. Fuwa, Y. Iwashita, Y. Nasu Kyoto ICR, Uji, Kyoto, Japan
	Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally.