Present status of BL19 TAKUMI at J-PARC

Harjo, S.; Aizawa, Kazuya; Kawasaki, Takuro; Gong, W.; Iwahashi, Takaaki; Ito, Takayoshi*; Abe, Jun*; Nakatani, Takeshi

no journal, , 

Evaluation of neutron instruments shield in J-PARC Materials and Life Science Experimental Facility

Oi, Motoki; Harada, Masahide; Kai, Tetsuya; Aizawa, Kazuya; Sato, Koichi; Masuyama, Koichi; Kasugai, Yoshimi

no journal, , 

In the J-PARC Materials and Life Science Experimental Facility (MLF), material science experiments using muon and neutron beam are performed. In the MLF, proton beam power was 300KW at May 2014 and it is planning to enhance to 1MW. For proton beam enhancement, we performed evaluation of the shielding performance of the neutron beam instruments. As a result, dose on the shield surface of 16 neutron instruments are sufficiently low for 1MW proton beam operation. However, 4 neutron instruments show high dose rate in particular neutron beam conditions. For these neutron instruments, we have checked the drawings and recalculate the shielding performance and considered a cause. Then based on the measurement results, some shield are added for these four neutron instruments and dose rate are reduced sufficiently to 1MW proton beam operation.

Measurement of high energy neutron intensity and distribution at a neutron- instrument of the J-PARC spallation-neutron-source

Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Ikeda, Yujiro

no journal, , 

In a spallation neutron source at Materials and Life Science Facility in J-PARC, 3GeV 1MW proton beam hits a mercury target and produced neutron beam provide to neutron instruments. Not only thermal and cold neutrons, but also high energy neutrons provide to the neutron instruments. The high energy neutrons about 1 MeV are available for a high energy neutron irradiation experiment. Because the high energy neutrons to provide the neutron instruments have been estimated by a simulation code, a validation of the high energy neutrons is necessary. In addition, neutron intensity and distribution at a sample position should be brought out as an irradiation field. Therefore, in NOBORU (BL10), high neutron intensity and distribution were measured with the foil activation method of Au, Al, Bi, In and Nb using threshold reactions in case with and without a thermal neutron filter. And the neutron distribution of the high energy neutrons was measured with an Al foil. The validation with the PHITS code indicates good agreement.

Development of sample radio-activity evaluation code at Materials and Life Science Facility in J-PARC

Harada, Masahide; Yamaguchi, Yuji; Hashimoto, Norimichi*; Ito, Taku*; Tajima, Takahiro*; Oku, Takayuki; Haga, Katsuhiro; Ikeda, Hiroshi*; Tamura, Satoshi*

no journal, , 

In Materials and Life Science Experimental Facility at J-PARC, carbon and mercury targets bombarded by 3 GeV and 1 MW proton beam produce muons and neutrons to provide to muon and neutron instruments. As the samples irradiated by muons and neutrons produce radioactive materials, an estimation of the radioactive materials produced in the irradiated samples is necessary for the stable operation and management of the facility. Therefore, a sample radio-activity evaluation code was developed using data from the DCHAIN-SP-2001 code. By selecting the irradiation conditions for each experiment and entering the information for each sample, the radio-activity of a sample can be calculated by multiplying the neutron flux by the activation cross section. The code is a servlet application, programed by JAVA, accessible on the Web, and can be used from the internal network. In the future, we will conduct activation experiments on various materials and validate this code.