High spatial resolution neutron transmission imaging using a superconducting two-dimensional detector

Shishido, Hiroaki*; Nishimura, Kazuma*; Vu, TheDang*   ; Aizawa, Kazuya  ; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi   ; Harada, Masahide   ; Oku, Takayuki   ; Soyama, Kazuhiko  ; Miyajima, Shigeyuki*; Hidaka, Mutsuo*; Suzuki, Soh*; Tanaka, Manobu*; Kawamata, Shuichi*; Ishida, Takekazu*

In this study, we employed a superconducting detector, current-biased kinetic-inductance detector (CB-KID) for neutron imaging using a pulsed neutron source. We employed the delay-line method, and high spatial resolution imaging with only four reading channels was achieved. We also performed wavelength-resolved neutron imaging by the time-of-flight method. We obtained the neutron transmission images of a Gd-Al alloy sample, inside which single crystals of GdAl were grown, using the delay-line CB-KID. Single crystals were well imaged, in both shapes and distributions, throughout the Al-Gd alloy. We identified Gd nuclei via neutron transmissions that exhibited characteristic suppression above the neutron wavelength of 0.03 nm. In addition, the Gd resonance dip, a dip structure of the transmission caused by the nuclear reaction between an isotope and neutrons, was observed even when the number of events was summed over a limited area of 15 m 12 m. Gd selective imaging was performed using the resonance dip of Gd, and it showed clear Gd distribution even with a limited neutron wavelength range of 1 pm.