Measuring Neutron Dose and Quality Factors with Tissue Equivalent Proportional Counters

摘要

The methods used to obtain absolute neutron dose measurements and quality factor determination from the tissue equivalent proportional counter (TEPC) are reviewed. Exposure to nearly monoenergetic neutrons with energies from 200 keV to 7.5 MeV indicate that the absorbed dose due to fast neutrons measured by the TEPC averaged 3% higher, with a standard deviation (1 sigma) of 9%, than the tissue kerma calculated from neutron fluence measurements. The absorbed dose due to fast neutrons measured by the TEPC agreed within 0.6% of the calculated tissue kerma for a PuBe neutron source, whose neutron yield was determined within 2% by the United States National Bureau of Standards. Data are presented which show the TEPC measures quality factors accurately enough for health physics purposes for neutrons with energies between 200 keV and 5 MeV. (ERA citation 05:012790)