Investigation of the ability to use IRF series power MOSFETs as gamma-ray dosimeters

In this paper, the ability of using IRF series power MOSFETs as gamma ray dosimeters was investigated. For this purpose, the threshold voltage shift generated by gamma ray radiation and the fading characteristics at room temperature, as the two main characteristics of the ideal dosimeter, for three types of power MOSFETs with a drain-source on resistance (RDS(on)) greater than 1Ω was measured and compared. Cobalt-60 source was used for irradiation at radiation dose in the range of 1-100krad with a dose rate of 10krad/h. The results show that the threshold voltage shift relative to the radiation dose has a good linearity for all three types of MOSFETs. Also, MOSFET with higher RDS(on) is more sensitive to gamma radiation. The fading characteristics for all three types of MOSFETs in the six-month period is less than 1%. Therefore, inexpensive IRF series MOSFETs are good candidates for gamma ray dosimetry.