Performance of optical devices for energy-selective neutron imaging in NOBORU at J-PARC

Harada, Masahide   ; Oikawa, Kenichi   ; Oi, Motoki ; Kai, Tetsuya   ; Shinohara, Takenao   ; Sakai, Kenji ; Maekawa, Fujio  

NOBORU at MLF in J-PARC serves a test beam port. Energy-selective neutron imaging is one of the important developments performed at NOBORU. In order to improve a spatial resolution and to reduce a background as the imaging experiment, a rotary collimator and a neutron filter device were installed on the middle of the beam-line. A revolver-shape shielding equipped with four holes is remotely rotated to change the collimator ratio from 140 to 1875. It was found from the neutron radiography test that neutron transmission images with high spatial resolution ( 100 m) could be obtained. In the remote-controlled filter device, it was confirmed that an acrylic resin plate and a borosilicate glass attenuated high-energy and cold neutrons, and bulk lead plates and bismuth single crystal ones attenuated the rays.