Development of a neutron area monitor and characterization system

A system for measuring the dose equivalent from neutron exposures has been developed. The system consists of a 30 cm diameter polyethylene sphere with thermoluminescent dosimeters mounted on it. The system has been exposed to various calibration and workplace neutron spectra. From these measurements a functional relationship for the neutron dose equivalent has been derived.

The functional relationship was tested using several different reference fields in which the dose equivalents were known. The resulting dose equivalents predicted by the functional relationship were within ±18% of the known dose equivalents. This system has also been tested in several locations where the neutron spectra were unknown. The results for the unknown spectra indicate that the system's center element response is the major component in the dose equivalent determination.

A tissue equivalent proportional counter (TEPC) system has also been utilized along with the sphere system. The TEPC was used to gather comparison data, and the results of the comparison have been presented.