Photoelectron emission as a tool to assess dose of electron radiation received by ZrO2:PbS films

Abstract

PbS nanodots embedded in ZrO2 thin film matrix (ZrO2:PbS films) were studied for application in nanodosimetry of electron radiation used in radiation therapy. ZrO2:PbS films were irradiated with 9 MeV electron radiation with doses 3, 7 and 10 Gy using medical linear accelerator. Detection of the dosimetric signal was made by measuring and comparing photoelectron emission current from ZrO2:PbS films before and after irradiation. It was found that electron radiation decreased intensity of photoemission current from the films. Derivatives of the photoemission spectra were calculated and maximums at photon energies 5.65 and 5.75 eV were observed. Amplitude of these maximums decreased after irradiation with electrons. Good linear correlation was found between the relative decrease of the intensity of these maximums and dose of electron radiation. Observed changes in photoemission spectra from ZrO2:PbS films under influence of electron radiation suggested that the films may be considered to be effective material for electron radiation dosimetry. Photoelectron emission is a tool that allows to read the signal from such dosimeter.