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Nishitani, Tomohiro; Hajima, Ryoichi; Iijima, Hokuto; Nagai, Ryoji; Sawamura, Masaru; Kikuzawa, Nobuhiro; Nishimori, Nobuyuki; Minehara, Eisuke; Tabuchi, Masao*; Noritake, Yosuke*; et al.
Proceedings of 28th International Free Electron Laser Conference (FEL 2006) (CD-ROM), p.319 - 322, 2006/08
ERL light source and FEL require an electron beam of large current and small emittance. In order to realize an electron gun satisfying such requirements,we started developments of a photocathode DC-gun and a new-type NEA-photocathode. The DC-gun consists of a chamber to activate NEA-surface, a 250 keV acceleration chamber, and a mode-locked Ti:Sapphire laser. Since extreme high vacuum is essential to obtain a long-life photocathode, we adopt a load-lock system for transporting a photocathode between the chambers, each of which is equipped with an NEG pump. Up to now, we fabricated an electrodes chamber and a high voltage terminal of 250 kV and we succeeded in a 250kV high voltage test. We also have suggested a superlattice photocathode as a new-type photocathode with higher performance than an existing technology. Up to now, we fabricated photocathode samples by molecular beam epitaxy and measured a quantum efficiency after NEA-surface activation.
Nishitani, Tomohiro; Tabuchi, Masao*; Noritake, Yosuke*; Hayashitani, Haruhiko*; Hajima, Ryoichi; Iijima, Hokuto; Nagai, Ryoji; Sawamura, Masaru; Kikuzawa, Nobuhiro; Nishimori, Nobuyuki; et al.
Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.45 - 47, 2006/00
no abstracts in English
Nishitani, Tomohiro; Noritake, Yosuke*
no journal, ,
An NEA-GaAs photocathode is expected as a high-brightness electron source satisfying the requirements of ERL-injectors. Although GaAs superlattice has been studied for polarized electron sources, the superlattice has never been applied to an ERL injector, which is usually equipped with GaAs in bulk. We propose GaAs superlattice as a photocathode for an ERL injector. The superlattice has larger NEA and larger joint density of state around band gap than bulk GaAs. These properties of GaAs superlattice will contribute to higher quantum efficiency and smaller emittance far beyond bulk GaAs. We present theoretical consideration based on Kronig-Penny model of the GaAs superlattice, and a future plan to develop the superlattice photocathode.
Nishitani, Tomohiro; Hajima, Ryoichi; Tabuchi, Masao*; Noritake, Yosuke*; Hayashitani, Haruhiko*
no journal, ,
no abstracts in English
Nishitani, Tomohiro; Hajima, Ryoichi; Takeda, Yoshikazu*; Tabuchi, Masao*; Noritake, Yosuke*
no journal, ,
no abstracts in English
Hajima, Ryoichi; Nishitani, Tomohiro; Iijima, Hokuto; Nagai, Ryoji; Nishimori, Nobuyuki; Tabuchi, Masao*; Noritake, Yosuke*; Hayashitani, Haruhiko*; Takeda, Yoshikazu*
no journal, ,
no abstracts in English
Nishitani, Tomohiro; Hajima, Ryoichi; Takeda, Yoshikazu*; Tabuchi, Masao*; Noritake, Yosuke*; Hayashitani, Haruhiko*
no journal, ,
no abstracts in English