PZT FOR MEASURING ENERGY FLUENCE RATE of X-RAY USED IN SUPERFICIAL CANCER THERAPY

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A PZT detector is used for measuring the energy fluence rate of X-ray pulses produced by superficial cancer therapy equipment (orthovoltage range). The instrument consists of a pyroelectric sensor, a low-noise high-sensitivity, current-to-voltage converter, a microcontroller and a digital display. The main element of the instrument is a pyroelectric sensor which consists of an iron-doped lead zirconate titanate ceramic disk. The response of the instrument exhibits a nonlinear relationship with the energy fluence rate of the radiation and the precision is better than 3%. The equipment is inexpensive, rugged, simple to construct, and has good long-term stability.