Neutron dosimetry with boron-doped CR-39 plastic.

概要

論文の詳細を見る
As a highly sensitive, simple and non-radioactive neutron dosimeter, CR-39 plastic plates doped with a boron compound : ortho-carborane were prepared. After thermal neutron irradiation, the plates were etched in an aqueous solution of 30%KOH, at 60°C for 2 to 16 h. The etch-pits generated by 10B(n, α)7Li reactions were then counted using an optical micro-scope or an automatic track counting system. The density of the etch-pits on an irradiated plate increases with the etching time. When the etching time is kept constant, the etch-pit density is proportional to the irradiated thermal neutron fluence. The proportional constant is termed "sensitivity", which is 4.2×10-4 for a plate containing ortho-carborane at a con-centration of 0.5% by weight and for etching time of 16 h. By considering background counts, a thermal neutron dose of 0.025 mSv can be measured with this plate. The plates are insensitive to visible-, UV-, X-, β- and γ-rays and are easy to handle because the detector and converter are incorporated. There is no possibility of underestimating the dose equivalent due to fading. Furthermore, the isotopes of boron are not radioactive and thus are radio-logically safe.
一般社団法人日本原子力学会の論文