抄録
A CR-39 plastic track detector has been applied to thermal neutron dosimetry by combining with a converter using (n, α) reactions. A ceramic boron nitride (BN) was utilized as the promising converter because of high boron-concentration and its smooth surface. The contribution of background tracks was evaluated in the region of CR-39 plastic unattached to BN converter. The detector was exposed to a reference neutron field generated by 252Cf source in a water tank in order to investigate the detection characteristics. It was found that the efficiency was (1.0 ± 0.1) × 10-3 pits/n, corresponding to the sensitivity of (9.6 ± 0.9) × 102 pits/mm2/mSv. The linear response was experimentally confirmed between 0.035 and 0.7 mSv. The minimum detectable dose equivalent was also estimated to be about 0.005 mSv.
