FEL2012 - List of Authors (Hajima, R.)

Paper	Title	Page
MOPD53	Development of a Photoemission DC Gun at JAEA	161
	N. Nishimori JAEA/FEL, Ibaraki-ken, Japan R. Hajima, S.M. Matsuba, R. Nagai JAEA, Ibaraki-ken, Japan Y. Honda, T. Miyajima, M. Yamamoto KEK, Ibaraki, Japan H. Iijima, M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan M. Kuwahara, T. Nakanishi, S. Okumi Nagoya University, Nagoya, Japan
	Funding: This work is supported by MEXT Quantum Beam Technology Program and partially supported by JSPS Grants-in-Aid for Scientific Research in Japan (23540353). The next generation light source such as X-ray FEL oscillator requires high brightness electron gun with megahertz repetition rate. We have developed a photoemission DC gun at JAEA. By employing a segmented insulator with rings which guard the ceramics from field emission, we successfully applied 500-kV on the ceramics with a center stem electrode for eight hours without any discharge in 2009. This high voltage testing was performed with a simple configuration without NEG pumps and electrodes. In 2011 we reached 526kV with NEG pumps and electrodes, before suffering another field emission problem from the cathode electrode. The problem may be attributed to small dust inside our gun chamber. We found wiping the cathode electrode with a lint free tissue could remove the field emission site effectively. Noble gas conditioning is also planned to remove the emission site without air exposure of the gun chamber.

WEPD30	Simulations of XFELO for the KEK ERL	433
	R. Hajima, N. Nishimori JAEA, Ibaraki-ken, Japan N. Nakamura, M. Shimada KEK, Ibaraki, Japan N. Sei AIST, Tsukuba, Ibaraki, Japan
	Following the recent development of high-brightness electron guns and high-reflectivity X-ray crystal optics, an FEL oscillator operated in a hard X-ray wavelength region (XFELO) has been considered as a possible extension of the 3-GeV ERL light source proposed at KEK. In order to deliver a 6-GeV electron beam to the XFELO, the ERL is operated at the energy-doubling mode with a low average current. In this paper, we present results of electron beam simulations and FEL simulations.

Paper

Title

Page

Development of a Photoemission DC Gun at JAEA

161

N. Nishimori
JAEA/FEL, Ibaraki-ken, Japan
R. Hajima, S.M. Matsuba, R. Nagai
JAEA, Ibaraki-ken, Japan
Y. Honda, T. Miyajima, M. Yamamoto
KEK, Ibaraki, Japan
H. Iijima, M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
M. Kuwahara, T. Nakanishi, S. Okumi
Nagoya University, Nagoya, Japan

Funding: This work is supported by MEXT Quantum Beam Technology Program and partially supported by JSPS Grants-in-Aid for Scientific Research in Japan (23540353).
The next generation light source such as X-ray FEL oscillator requires high brightness electron gun with megahertz repetition rate. We have developed a photoemission DC gun at JAEA. By employing a segmented insulator with rings which guard the ceramics from field emission, we successfully applied 500-kV on the ceramics with a center stem electrode for eight hours without any discharge in 2009. This high voltage testing was performed with a simple configuration without NEG pumps and electrodes. In 2011 we reached 526kV with NEG pumps and electrodes, before suffering another field emission problem from the cathode electrode. The problem may be attributed to small dust inside our gun chamber. We found wiping the cathode electrode with a lint free tissue could remove the field emission site effectively. Noble gas conditioning is also planned to remove the emission site without air exposure of the gun chamber.

WEPD30

Simulations of XFELO for the KEK ERL

433

R. Hajima, N. Nishimori
JAEA, Ibaraki-ken, Japan
N. Nakamura, M. Shimada
KEK, Ibaraki, Japan
N. Sei
AIST, Tsukuba, Ibaraki, Japan

Following the recent development of high-brightness electron guns and high-reflectivity X-ray crystal optics, an FEL oscillator operated in a hard X-ray wavelength region (XFELO) has been considered as a possible extension of the 3-GeV ERL light source proposed at KEK. In order to deliver a 6-GeV electron beam to the XFELO, the ERL is operated at the energy-doubling mode with a low average current. In this paper, we present results of electron beam simulations and FEL simulations.