IPAC2016 - List of Authors (Katoh, M.)

Paper	Title	Page
TUPOY046	Study on NRF-CT Imaging by Laser Compton Backscattering Gamma-rays in UVSOR	2007
	H. Ohgaki, I. Daito, T. Kii, H. Zen Kyoto University, Kyoto, Japan T. Hayakawa, T. Shizuma JAEA, Ibaraki-ken, Japan M. Katoh, J. Yamazaki UVSOR, Okazaki, Japan Y. Taira, H. Toyokawa AIST, Ibaraki, Japan
	Funding: This work was supported by JSPS KAKENHI Grant Number 26289363, 24340060 and the Joint Studies Program (2014) of the Institute for Molecular Science. Monochromatic gamma-ray beam in MeV energy region is suitable for non-destructive inspection of high density and massive objects because of its high penetrability. A specific nuclide can be detected by the process of Nuclear Resonance Fluorescence (NRF). A non-destructive inspection of Special Nuclear Materials hidden in a container cargo using NRF is proposed by Bertozzi. Non-destructive detection of Pu inside of a spent nuclear fuel rod is also proposed for management of radioactive wastes, nuclear material accounting and safeguards. We have developed 2D NRF imaging by using quasi-monochromatic gamma-ray beam in MeV energy region generated by Laser Compton Backscattering (LCS) method** and proposed to develop an NRF-CT image in the ELI-NP where a high intensity LCS beam can be available in near future. To demonstrate and finalize the measurement system of the NRF-CT imaging by using LCS gamma-ray beam, we have started a study on NRF-CT imaging at the new LCS beamline in UVSOR. The LCS beamline can generate 5.4 MeV LCS gamma-rays with a flux of 1×10⁷ photons/s. We have measured the 5.291 MeV NRF gamma-rays from a lead target in this beamline and tried to take a NRF-CT image. * W. Bertozzi et al., Nucl. Inst. Meth. B241, 820-825 (2005). B. Ludewigt et al., Proc. of 2010 ANS meeting (2010). * H. Toyokawa et al., JJAP, 50, 100209 (2011).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY046
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WEOAA03	Experimental Study on Optical Vortex from a Helical Undulator at UVSOR-III	2036
	M. Hosaka Nagoya University, Nagoya, Japan M. Katoh, N.S. Mirian UVSOR, Okazaki, Japan T. Konomi, N. Yamamoto KEK, Ibaraki, Japan K. Kuroda ISSP, Kashiwa-shi, Japan K. Miyamoto, S. Sasaki HSRC, Higashi-Hiroshima, Japan
	A relativistic electron in helical undulator emits an optical vortex which carries orbital angular momentum. Sasaki and McNulty predicted theoretically that higher harmonics of helical undulator is optical vortex* and the experimental verification was made at BESSY and UVSOR-III. Further, we have made a systematic study to characterize the optical vortex from a helical undulator at UVSOR-III. Synchrotron radiation in UV region from an optical klystron undulator system consisting of two APPLE-II helical undulators and a buncher was used for the experiment. Patterns resulting from inferences between two undulator radiation carrying different angular momentums were clearly observed. To investigate the optical properties of the radiation, diffraction experiments were carried out. Specific diffraction patterns due to the phase singularity in the radiation center were clearly observed. The experimental results are compared with simulation. S. Sasaki, I. McNulty, Phys. Rev. Lett. 100, 124801 (2008) J. Bahrdt et al., Phys. Rev. Lett. 111, 034801 (2013) * e.g. S. Sasaki et al., presented in SRI2015 (2015)
	Slides WEOAA03 [11.023 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA03
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WEPMY039	Time Response Measurements for Transmission-Type GaAs/GaAsP Superlattice Photocathodes	2641
	N. Yamamoto, X.J. Jin KEK, Ibaraki, Japan M. Hosaka, Y. Takashima, K. Yamaguchi Nagoya University, Nagoya, Japan M. Katoh UVSOR, Okazaki, Japan
	Polarized electron beam is essential for future electron-positron colliders and electron-ion colliders. Recently we have developed the strain compensated superlattice (SL) photocathode. In the strain compensated SLs, the equivalent compressive and tensile strains introduced in the well and barrier SL layers so that strain relaxation is effectively suppressed with increasing the SL layer thickness and high crystal quality can be expected. In this study, we fabricated the GaAs/GaAsP strain compensated SLs with the thickness up to 90-pair SL layers. Up to now, the electron spin polarization of 92 % and the quantum efficiency of 1.6 % were simultaneously achieved from 24-pair sample. In this study, to compare the time response performances with the SL thicknesses, the measurements were carried out for conventional and strain compensated SL PCs. We show the measurement results and discuss the physics.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY039
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WEPOW023	Present Status of Accelerators in Aichi Synchrotron Radiation Center	2877
	Y. Takashima, M. Hosaka, A. Mano Nagoya University, Nagoya, Japan Y. Hori, N. Yamamoto KEK, Ibaraki, Japan M. Katoh UVSOR, Okazaki, Japan S. Koda SAGA, Tosu, Japan S. Sasaki JASRI/SPring-8, Hyogo, Japan T. Takano Hitachi Ltd., Ibaraki-ken, Japan
	Aichi Synchrotron Radiation Center is the newest synchrotron radiation facility in Japan. The construction was started in 2010 and the facility was opened for public use on March 26, 2013. The circumference of the storage ring is 72 m with the electron energy of 1.2 GeV, the beam current of 300 mA and the natural emittance of about 53 nmrad. The beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection and the top-up operation has been carried out routinely with stored current of 300 mA since opened for public use. We have tested a pulsed multi-pole magnet for improving the deviation of the orbit of stored beam during the top-up beam injection. The storage ring consists of four triple bend cells. Eight of the twelve bending magnets are normal conducting ones. Four of them are 5 T superconducting magnets(superbend) of which bending angle is 12 degrees. The superbends are running without any trouble with refrigerator maintenance once per year. The accelerators have been operated about 1400 hours stable in a year. Eight of the synchrotron radiation beamlines have been operational for public use and other two beamlines are under construction.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW023
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Paper

Title

Page

Study on NRF-CT Imaging by Laser Compton Backscattering Gamma-rays in UVSOR

2007

H. Ohgaki, I. Daito, T. Kii, H. Zen
Kyoto University, Kyoto, Japan
T. Hayakawa, T. Shizuma
JAEA, Ibaraki-ken, Japan
M. Katoh, J. Yamazaki
UVSOR, Okazaki, Japan
Y. Taira, H. Toyokawa
AIST, Ibaraki, Japan

Funding: This work was supported by JSPS KAKENHI Grant Number 26289363, 24340060 and the Joint Studies Program (2014) of the Institute for Molecular Science.
Monochromatic gamma-ray beam in MeV energy region is suitable for non-destructive inspection of high density and massive objects because of its high penetrability. A specific nuclide can be detected by the process of Nuclear Resonance Fluorescence (NRF). A non-destructive inspection of Special Nuclear Materials hidden in a container cargo using NRF is proposed by Bertozzi*. Non-destructive detection of Pu inside of a spent nuclear fuel rod is also proposed for management of radioactive wastes, nuclear material accounting and safeguards**. We have developed 2D NRF imaging by using quasi-monochromatic gamma-ray beam in MeV energy region generated by Laser Compton Backscattering (LCS) method*** and proposed to develop an NRF-CT image in the ELI-NP where a high intensity LCS beam can be available in near future. To demonstrate and finalize the measurement system of the NRF-CT imaging by using LCS gamma-ray beam, we have started a study on NRF-CT imaging at the new LCS beamline in UVSOR. The LCS beamline can generate 5.4 MeV LCS gamma-rays with a flux of 1×10⁷ photons/s. We have measured the 5.291 MeV NRF gamma-rays from a lead target in this beamline and tried to take a NRF-CT image.
* W. Bertozzi et al., Nucl. Inst. Meth. B241, 820-825 (2005).
** B. Ludewigt et al., Proc. of 2010 ANS meeting (2010).
*** H. Toyokawa et al., JJAP, 50, 100209 (2011).

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY046

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WEOAA03

Experimental Study on Optical Vortex from a Helical Undulator at UVSOR-III

2036

M. Hosaka
Nagoya University, Nagoya, Japan
M. Katoh, N.S. Mirian
UVSOR, Okazaki, Japan
T. Konomi, N. Yamamoto
KEK, Ibaraki, Japan
K. Kuroda
ISSP, Kashiwa-shi, Japan
K. Miyamoto, S. Sasaki
HSRC, Higashi-Hiroshima, Japan

A relativistic electron in helical undulator emits an optical vortex which carries orbital angular momentum. Sasaki and McNulty predicted theoretically that higher harmonics of helical undulator is optical vortex* and the experimental verification was made at BESSY** and UVSOR-III***. Further, we have made a systematic study to characterize the optical vortex from a helical undulator at UVSOR-III. Synchrotron radiation in UV region from an optical klystron undulator system consisting of two APPLE-II helical undulators and a buncher was used for the experiment. Patterns resulting from inferences between two undulator radiation carrying different angular momentums were clearly observed. To investigate the optical properties of the radiation, diffraction experiments were carried out. Specific diffraction patterns due to the phase singularity in the radiation center were clearly observed. The experimental results are compared with simulation.
* S. Sasaki, I. McNulty, Phys. Rev. Lett. 100, 124801 (2008)
** J. Bahrdt et al., Phys. Rev. Lett. 111, 034801 (2013)
*** e.g. S. Sasaki et al., presented in SRI2015 (2015)

Slides WEOAA03 [11.023 MB]

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA03

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WEPMY039

Time Response Measurements for Transmission-Type GaAs/GaAsP Superlattice Photocathodes

2641

N. Yamamoto, X.J. Jin
KEK, Ibaraki, Japan
M. Hosaka, Y. Takashima, K. Yamaguchi
Nagoya University, Nagoya, Japan
M. Katoh
UVSOR, Okazaki, Japan

Polarized electron beam is essential for future electron-positron colliders and electron-ion colliders. Recently we have developed the strain compensated superlattice (SL) photocathode. In the strain compensated SLs, the equivalent compressive and tensile strains introduced in the well and barrier SL layers so that strain relaxation is effectively suppressed with increasing the SL layer thickness and high crystal quality can be expected. In this study, we fabricated the GaAs/GaAsP strain compensated SLs with the thickness up to 90-pair SL layers. Up to now, the electron spin polarization of 92 % and the quantum efficiency of 1.6 % were simultaneously achieved from 24-pair sample. In this study, to compare the time response performances with the SL thicknesses, the measurements were carried out for conventional and strain compensated SL PCs. We show the measurement results and discuss the physics.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY039

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WEPOW023

Present Status of Accelerators in Aichi Synchrotron Radiation Center

2877

Y. Takashima, M. Hosaka, A. Mano
Nagoya University, Nagoya, Japan
Y. Hori, N. Yamamoto
KEK, Ibaraki, Japan
M. Katoh
UVSOR, Okazaki, Japan
S. Koda
SAGA, Tosu, Japan
S. Sasaki
JASRI/SPring-8, Hyogo, Japan
T. Takano
Hitachi Ltd., Ibaraki-ken, Japan

Aichi Synchrotron Radiation Center is the newest synchrotron radiation facility in Japan. The construction was started in 2010 and the facility was opened for public use on March 26, 2013. The circumference of the storage ring is 72 m with the electron energy of 1.2 GeV, the beam current of 300 mA and the natural emittance of about 53 nmrad. The beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection and the top-up operation has been carried out routinely with stored current of 300 mA since opened for public use. We have tested a pulsed multi-pole magnet for improving the deviation of the orbit of stored beam during the top-up beam injection. The storage ring consists of four triple bend cells. Eight of the twelve bending magnets are normal conducting ones. Four of them are 5 T superconducting magnets(superbend) of which bending angle is 12 degrees. The superbends are running without any trouble with refrigerator maintenance once per year. The accelerators have been operated about 1400 hours stable in a year. Eight of the synchrotron radiation beamlines have been operational for public use and other two beamlines are under construction.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW023

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