Design and simulation of betavoltaic angle sensor Based on Ni-63-Si

摘要

A theoretical design and simulation of betavoltaic angle sensor (beta-AS) based on Ni-63-Si using MCNP code is presented in this article. It can measure the full angle of 0-360 degrees in the temperature range of 233-353 K. Beta-AS is composed of semicircular Ni-63 as the beta source, which rotates along the circular (four-quadrant) surface of Si as a semiconductor (in p-n structure), so that the change in the source angle in relation to Si surface can be measured based on the changes in V-oc, observed in each quadrant of Si. For better performance, characteristics of Si and Ni-63 have been optimized: N-D and N-A values of 8e19 and 4e18 cm(-3) (donor and acceptor doping concentration in Si, respectively), source thickness and activity of 1.5 mu m and 18 mCi, respectively. The relation between angle and V-oc is also investigated. The maximum difference between measured and real values of angle (the worst case, i.e., 0.18 degrees for the angle of 45 degrees) occurs at 233 K. It has been shown that sensitivity of the sensor decreases with an increase of angle. The results also show that the change in activity does not affect the sensitivity. (C) 2015 Elsevier Ltd. All rights reserved.