Dose Rate Dependence of Diode Radiation Detector for Pulsed Radiation

Tomothy C. Zhu,
Univ. of Pennsylvania

A diode radiation detector is often used for in-vivo patient dosimetry to verify overall patient treatment quality with respect to calculation, setup, and delivery for radiation therapy.

The non-linear differential equation for the transient response of radiation current was solved numerically using FEMLAB to determine the diode sensitivity as a function of instantaneous dose rate. The numerical solution is then compared with an analytical approximation, obtained assuming constant minority carrier lifetime, t. We found that the analytical expression overestimate S. Correction factors are established for a number of diode detectors.

An improved formula based on the numerical solution is introduced to improve the prediction of dose rate dependence.