Abstract
Electron beams (EBs) at energies of 300 keV or lower have a potential to be utilized for purification of polluted waste gases. Such low-energy electrons are scattered in waste gases, and consequently in the state having nonuniform distribution of absorbed dose rate. Dosimetry in the gas is, therefore, necessary for designing the efficient treatment system of waste gas using EBs. In the present work, the dosimetry study for 300 keV electron beams was performed in ambient air of irradiation vessel (or in an irradiation vessel filled with ambient air) using two kinds of polymer film dosimeters for dose rate measurement, a prototype totalabsorption aluminum calorimeter for energy fluence measurement, and semi-empirical calculation using EDMULT code for depth-dose distribution estimation. The four results were compared concerning dose rate distribution or energy fluence as a function of depth in gas. As a result, the depth-dose rate distribution results obtained by the polymer film dosimeters were in good agreement with the EDMULT code calculation results considering electrons scattering in air. Energy fluence measured by a prototype calorimeter was 8-11 % lower than that estimated by both two different polymer film dosimeters. The difference is reasonably small, considering the experimental errors. These results demonstrate that polymer film dosimeters can be used for dosimetry in low-energy EB irradiation field when they are calibrated against this simple calorimeter under practical irradiation condition.
