An in-situ calibration device for portable gamma dosimeters based on minitype reference radiation

This paper reports an in-situ calibration device for portable gamma dosimeters based on the minitype reference radiation (MRR). Compared to the standard reference radiation (SRR) regulated by the ISO-4037 series standards for gamma dosimeter calibration purposes, the dimensions of the MRR of the device were drastically reduced to 0.6 m x 0.6 m x 0.6 m, and the total weight of the device was approximately 800 kg. According to the test experiments, the device met the radiation protection requirements, and the air kerma rate range covered 1 mu Gy/h-10 mGy/h, which is appropriate for calibrating protection level gamma dosimeters. A series of dosimeters were calibrated in the SRR and the device, and the mean deviation of the calibration factors was approximately 5.66%.