CR39 Fast/Thermal Neutron Personal Dosimeter Used in IM for Occuptional External Exposure
CAO Lei1,DENG Jun1,ZHANG Gui-ying2,LIU Yun-hong1,GUO Wen1,HU Ai-ying1
1. National Institute for Radiological Protection Chinese Center for Disease Control and Prevention,Beijing 100088, China
2. China Institute of Atomic Energy, Beijing 102413, China
Abstract：Neutron personal dose monitoring is an important part of external monitoring for occupational exposure. From neutron detecting theory of CR39 and dosimeter structure points of view, experiments regarding energy response and angle response as well as dose equivalent response of CR39 neutron personal dosimeter against neutron emitted by Am-Be were carried out. Results show that neutron flux sensitivity strongly depends on the energy and incident angle of neutron. The critical angle of 64° for incident neutron and neutron dose equivalent sensitivity of about 2.14×10-4tracks/(n·cm2) are obtained. The externally-assigned response of CR39 detector is improved through increasing the track density by using the α particle induced by the reaction of 10B（n,α）7Li with the BN as pre-recoil layer, and the increase is vilified by using both Monte-Carlo simulation and experiment exposed by standard neutron source. The personal dosimeter have the ability to distinguish fast/thermol neutrons.
［1］ISO 8529-1-2000, Reference neutron radiations Part 1: Characteristics and methods of production［S］.
［2］GBZ128-2002,职业性外照射个人剂量监测规范［S］.
［3］Oda K, Hiroshi M, Masami M. CR39-BN detector for thermal neutron dosimetry［J］.J Nucl Sci Technol, 1987, 24(2): 129-134.
［4］ICRP. Conversion coefficients for use in radiological protection against external radiation［R］. ICRP Report No74,1997.
2011, Vol. 32 
