FISSION REACTOR IRRADIATION TESTS OF BOLOMETER

摘要

A Bolometer, which is a calorimeter to measure energy deposition rate on its surface, and is composed of a gold meander on Muscovite mica thin plate, was irradiated in a Japan Materials Testing Reactor (JMTR), up to O.ldpa, below 150C. Performance of the bolometer was evaluated in-situ during JMTR irradiation. Also, post-irradiation examination was carried out on the irradiated bolometer. The swelling of Muscovite was less than 0.3% after irradiation up to 2.2x1023n/m2 fast neutron fluence. No explicit deformation of the thin plates was recognized. The bolometer showed good performance under irradiation, but a large increase of electrical resistance of the gold meander was observed. This could be explained by introduction of about 50% mercury (Hg) atoms in the gold meander by nuclear transmutation, which made gold thin film brittle and also introduced a strong internal stress in the gold film, resulting in the exfoliation of the gold film from its Muscovite mica substrate.