IPAC2011 - List of Authors (Koda, S.)

Paper	Title	Page
TUPO014	High-flux Gamma-ray Generation by Laser Compton Scattering in the SAGA-LS Storage Ring	1476
	T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi SAGA, Tosu, Japan
	We constructed an experimental setup for high-flux gamma-ray generation by laser Compton scattering (LCS) in the SAGA-LS storage ring. The SAGA-LS is a synchrotron radiation (SR) facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring. We employed a CO2 laser having a wavelength of 10.6 micrometer to produce gamma-rays in the few MeV region in conjunction with the SR user time. The LCS gamma-ray up to the maximum energy of 3.5 MeV is generated via head-on collision between the laser photons and the 1.4 GeV stored beam. Since the energy acceptance of the storage ring is well above the maximum gamma-ray energy, the LCS experiment can be performed without reducing the beam lifetime. As a first step for high-flux gamma-ray generation, we use a small 10 W CO2 laser for beam test. The LCS event rate is designed to be 2·10⁸ ph/s with a beam current of 300 mA and a laser power of 10 W. A further increase of the LCS event rate in the order of 10¹0 ph/s is expected when a kW class laser is utilized. We report on the characteristics of the LCS gamma-rays observed in the low current beam test and an experimental result for evaluating the gamma-ray flux at a current of 300 mA.

THPC037	Accelerators of the Central Japan Synchrotron Radiation Facility Project (II)	2987
	N. Yamamoto, M. Hosaka, A. Mano, H. Morimoto, K. Takami, Y. Takashima Nagoya University, Nagoya, Japan Y. Hori KEK, Ibaraki, Japan M. Katoh UVSOR, Okazaki, Japan S. Koda SAGA, Tosu, Japan S. Sasaki JASRI/SPring-8, Hyogo-ken, Japan
	Central Japan Synchrotron Radiation (SR) Facility Project is making progress for the service from FY2012. The construction of SR building is almost completed in the Aichi area of Japan, and the installs of accelerators will start in a few week. The key equipments of our accelerators are an 1.2 GeV compact electron storage ring that is able to supply hard X-rays and a full energy injector for top-up operation. The beam current and natural emittance of the storage ring are 300 mA and 53 nmrad. The circumference is 72 m. The magnetic lattice consists of four triple bend cells and four straight sections. The bending magnets at the centers of the cells are 5 T superconducting magnets and the critical energy of the SR is 4.8 keV. The injector consists of a 50 MeV linac and a booster synchrotron with the circumference of 48 m. To save construction expenses, the injector is built at inside of the storage ring. More than ten hard X-ray beam-line can be constructed. One variable polarization undulator will be installed in the first phase. The top-up operation will be introduced as early as possible.

THPC042	Status and Development of the SAGA Light Source	2996
	T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi SAGA, Tosu, Japan
	The SAGA Light Source (SAGA-LS) is a synchrotron radiation facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring, and has been stably providing synchrotron light since 2006. The annual failure time is less than 1% of the user time in the recent two years. Three insertion devices are installed in the storage ring: an APPLE-II undulator, a planar type undulator (Saga Univ.) and a 4 T superconducting wiggler (SCW). The SCW contains a hybrid three-pole magnet; the main pole of the magnet is surrounded by superconducting coils while side poles are normal conducting magnets. The main pole of the SCW is cooled by a GM cryocooler, which allows the SCW be operated without liquid helium. Since the installation in March 2010, the SCW has been operated stably. To control the ID parameters during the user time, a feed-forward correction system which minimizes the ID effects on the emittance coupling was developed. The laser Compton Gamma-rays were generated by using a CO2 laser and were used for beam energy measurement. In addition, research works on the beam lifetime and interaction between electron beam and crystal, and development of a multipole magnet are in progress.

Paper

Title

Page

High-flux Gamma-ray Generation by Laser Compton Scattering in the SAGA-LS Storage Ring

1476

T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi
SAGA, Tosu, Japan

We constructed an experimental setup for high-flux gamma-ray generation by laser Compton scattering (LCS) in the SAGA-LS storage ring. The SAGA-LS is a synchrotron radiation (SR) facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring. We employed a CO2 laser having a wavelength of 10.6 micrometer to produce gamma-rays in the few MeV region in conjunction with the SR user time. The LCS gamma-ray up to the maximum energy of 3.5 MeV is generated via head-on collision between the laser photons and the 1.4 GeV stored beam. Since the energy acceptance of the storage ring is well above the maximum gamma-ray energy, the LCS experiment can be performed without reducing the beam lifetime. As a first step for high-flux gamma-ray generation, we use a small 10 W CO2 laser for beam test. The LCS event rate is designed to be 2·10⁸ ph/s with a beam current of 300 mA and a laser power of 10 W. A further increase of the LCS event rate in the order of 10¹0 ph/s is expected when a kW class laser is utilized. We report on the characteristics of the LCS gamma-rays observed in the low current beam test and an experimental result for evaluating the gamma-ray flux at a current of 300 mA.

THPC037

Accelerators of the Central Japan Synchrotron Radiation Facility Project (II)

2987

N. Yamamoto, M. Hosaka, A. Mano, H. Morimoto, K. Takami, Y. Takashima
Nagoya University, Nagoya, Japan
Y. Hori
KEK, Ibaraki, Japan
M. Katoh
UVSOR, Okazaki, Japan
S. Koda
SAGA, Tosu, Japan
S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan

Central Japan Synchrotron Radiation (SR) Facility Project is making progress for the service from FY2012. The construction of SR building is almost completed in the Aichi area of Japan, and the installs of accelerators will start in a few week. The key equipments of our accelerators are an 1.2 GeV compact electron storage ring that is able to supply hard X-rays and a full energy injector for top-up operation. The beam current and natural emittance of the storage ring are 300 mA and 53 nmrad. The circumference is 72 m. The magnetic lattice consists of four triple bend cells and four straight sections. The bending magnets at the centers of the cells are 5 T superconducting magnets and the critical energy of the SR is 4.8 keV. The injector consists of a 50 MeV linac and a booster synchrotron with the circumference of 48 m. To save construction expenses, the injector is built at inside of the storage ring. More than ten hard X-ray beam-line can be constructed. One variable polarization undulator will be installed in the first phase. The top-up operation will be introduced as early as possible.

THPC042

Status and Development of the SAGA Light Source

2996

T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi
SAGA, Tosu, Japan

The SAGA Light Source (SAGA-LS) is a synchrotron radiation facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring, and has been stably providing synchrotron light since 2006. The annual failure time is less than 1% of the user time in the recent two years. Three insertion devices are installed in the storage ring: an APPLE-II undulator, a planar type undulator (Saga Univ.) and a 4 T superconducting wiggler (SCW). The SCW contains a hybrid three-pole magnet; the main pole of the magnet is surrounded by superconducting coils while side poles are normal conducting magnets. The main pole of the SCW is cooled by a GM cryocooler, which allows the SCW be operated without liquid helium. Since the installation in March 2010, the SCW has been operated stably. To control the ID parameters during the user time, a feed-forward correction system which minimizes the ID effects on the emittance coupling was developed. The laser Compton Gamma-rays were generated by using a CO2 laser and were used for beam energy measurement. In addition, research works on the beam lifetime and interaction between electron beam and crystal, and development of a multipole magnet are in progress.