The effect of an external electric field on radiation transmission and Compton scattering in plexiglass

The effect of an external electric field on radiation transmission of a plexiglass sample has been studied by using an extremely narrow-collimated-beam transmission method. Also, the photon scattering properties of the charge centers have been determined by changing the charge density distributions of the plexiglass sample with an external electric field having an intensity in the range 0–1000 V/cm. The plexiglass sample was bombarded by 59.5 keV gamma rays emitted from an Am-241 point source. The transmitted and Compton scattered photons were detected by a Si(Li) detector. Appreciable variations were observed in the transmission factors of the plexiglass sample as a function of applied field. The results show that the electrical properties of the plexiglass sample changes with the applied electric field and the gamma ray irradiations although it is a dielectric material. Furthermore, the negatively charged scattering centers are slightly more effective than the positively charged scattering centers in the Compton scattering of gamma rays from an insulator sample, similar to result found for conductor and semiconductors.