Calibration Techniques for Personnel Dosemeters in Stray Neutron Fields

Abstract

The energy response of personnel neutron dosemeters is such that a fairly sophisticated field calibration of any dosemeter is necessary in each neutron field encountered. This critical review of calibration techniques discusses the different aspects determining field reference data, i.e., the response of the dosemeter and the neutron dose equivalent. The fundamental problems of field calibration result from the absence of dose rate meters that are energy independent, the need for the estimation of calibration factors using phantom irradiations in multidirectional fields, and the need for extended field measurements at all work locations of interest. Because of changes in space or time of the calibration factor at one facility, the use of two-component dosemeters (which provide an intrinsic correction of the calibration factor by the dosemeter itself) is highly desirable. Examples are presented of techniques for determining field calibration factors; these illustrate the capability of the common techniques and indicate a need for standardisation.