Energy response improvement for photon dosimetry using pulse analysis

Abstract：

During the last few years, active personal dosimeters have been developed and have replaced passive personal dosimeters in some external monitoring systems, frequently using silicon diode detectors. Incident photons interact with the constituents of the diode detector and produce electrons. These photon-induced electrons deposit energy in the detector's sensitive region and contribute to the response of diode detectors. To achieve an appropriate photon dosimetry response, the detectors are usually covered by a metallic layer with an optimum thickness. The metallic cover acts as an energy compensating shield. In this paper, a software process is performed for energy compensation. Selective data sampling based on pulse height is used to determine the photon dose equivalent. This method is applied to improve the energy response in photon dosimetry. The detector design is optimized for the response function and determination of the photon dose equivalent. Photon personal dose equivalent is determined in the energy range of 0.3-6 MeV. The error values of the calculated data for this wide energy range and measured data for ¹³³Ba, ¹³⁷Cs, ⁶⁰Co and ²⁴¹Am-Be sources respectively are up to 20% and 15%. Fairly good agreement is seen between simulation and dose values obtained from our process and specifications from several photon sources.