Results of shielding performance test in rise-to-power test of the HTTR

Ueta, Shohei; Takada, Eiji*; Sumita, Junya; Shimizu, Atsushi; Ashikagaya, Yoshinobu; Umeda, Masayuki; Sawa, Kazuhiro

JAERI-Tech 2004-047, 87 Pages, 2004/06

JAERI-Tech-2004-047.pdf:6.24MB

In the radiation shielding design of the High Temperature Engineering Test Reactor (HTTR), strong attention is needed to avoid especially upward neutron streaming. Shielding performance test have been carried out in the Rise-to-power test up to full power operation of 30MW. The measured dose equivalent rates in unrestricted area were lower than the detection limit for neutron-ray, and background level for -ray. The neutron dose equivalent rate measured in the stand pipes room was about 120Sv/h at full power operation, which was much lower than the shielding design (330 mSv/h) and the prediction (10 mSv/h).

Radiation response of fill-factor for GaAs solar cells with InGaAs quantum dot layers

Nakamura, Tetsuya*; Sumita, Taishi*; Imaizumi, Mitsuru*; Sugaya, Takeyoshi*; Matsubara, Koji*; Niki, Shigeru*; Mochizuki, Toru*; Takeda, Akihiro*; Okano, Yoshinobu*; Sato, Shinichiro; et al.

no journal, , 

Radiation effects on GaAs solar cells with InGaAs dot layers were investigated in order to consider the capability of them for space applications. The GaAs solar cells with 50 InGaAs dot layers and also GaAs solar cells with no dot layer were fabricated using a MBE method. They were irradiated with 150 keV-protons at room temperature. As a result, solar cell with dot layers showed higher radiation degradation in short circuit current however, lower degradation in open circuit voltage. Since no significant difference in the degradation of current - voltage characteristics under dark conditions between dot and non-dot solar cells, it is concluded that the degradation of fill fuctor does not come from the degradation of pn diode characteristics but might come from the degradation of minority carrier diffusion length.

Evaluation of radiation degradation of GaAs solar cells with InGaAs quantum dot layers using radiation induced current

Oshima, Takeshi; Nakamura, Tetsuya*; Sumita, Taishi*; Imaizumi, Mitsuru*; Sato, Shinichiro; Sugaya, Takeyoshi*; Matsubara, Koji*; Niki, Shigeru*; Mochizuki, Toru*; Okano, Yoshinobu*

no journal, ,