Optimization design of Compton detector

The Compton detector, with fast time response, linear range over many orders of magnitude and low sensitivity to X-ray fluxes, can be used to measure the dose of time resolved X-ray, whose sensitivity is decided by the materials and dimensions of its collector, dielectric and metal case. Since the detector dimension is energy dependent, there will be an optimal dimension for a detector to measure Bremsstrahlung X-ray dose. Monte-Carlo method was used to design a Compton detector which will be used to measure the Bremsstrahlung X-ray dose produced by the Dragon-I accelerator. The Bremsstrahlung spectrum of Dragon-I was computed by MCNP program, as well as the Compton electron number as a function of plexiglass thickness, aluminum case thickness and plomb collector thickness. According to the calculated results an optimal Compton detector has been designed. Its energy response of sensitivity was calculated and the results is not as good as expected. Thus the detector was modified with aluminum in front of the collector and the calculated sensitivity for Bremsstrahlung produced by Dragon-I is improved to 6.86 x 1011 (C/kg)-1. (authors)