Design and optimization of beta-cell temperature sensor based on ⁶³Ni-Si

A theoretical study of the use of a beta-cell as a temperature sensor using MCNP4C Monte Carlo code is presented in this paper. Nickel-63 and silicon were selected as the beta source and semiconductor material, respectively. The maximum open-circuit voltage (VOC) is equal to 0.445 V with doping concentrations of NA=4 × 10(18)#/cm(3) and ND=8 × 10(19)#/cm(3) in the base and the emitter region, respectively, which, depending on the source activity, enables measurement in a wide range of temperature. The effects of the activity and its change over time on VOC were also studied. The results demonstrated that VOC exhibited smaller changes for higher activities. The temperature sensitivity of this sensor ranges from -2.42 mV/K to -3.41 mV/K for source activities from 100 mCi to 0.001 mCi, respectively, so the optimal activity can be determined according to the desired temperature range and sensitivity.