关键词: 地面模型, 剂量率, 定值研究, 空间分布, 结果比对

Abstract: The calibration pad is constructed according to IAEA Technical Reports Series No.174 for the calibration of portable gamma spectrometer,gamma radiometer metering device,initially mainly used in geological exploration.From 2016 to 2018,two new pads with potassium concentration of 30 % (YK3) and uranium concentration of 1 % (YU4) were developed and determined.The dose rate at the location far away from the center of the pad surface was low,and increased gradually as the center point approached.The dose rate plateau zones of YK3 and YU4 were within the radius of about 40 cm and 50 cm around the pad center point,respectively,and the change of dose rate within the plateau zone was no more than 0.6 %;The dose rates at the 3.0 cm height of the central point were 320.8 nGy·h^-1 and 4.3×10⁴ nGy·h^-1,respectively.When the height exceeded 3.0 cm,the dose rate changed non-linearly with height.According to the comparison between the theoretical calculation and the measured results at different heights,within the height of 40 cm,the relative deviation between the measured results of YK3 and the theoretical calculation results is within 3 %;within the height of 120 cm,the relative deviation between the measured results of YU4 and the theoretical calculation results is within 2 %.

Key words: Calibration pad, Dose rate, Study on determining, Spatial distribution, Result comparison