Gas-Phase Dosimetry by Use of Ionization Measurements

Publisher Website
Google Scholar
Abstract
A basis is provided for the use of ionization measurements to evaluate energy absorption in gas‐phase dosimetry when high‐energy electrons are employed as the radiation source. It is concluded that total energy absorption can be determined and that stopping powers can be employed to calculate relative energy absorption in various gases. Scattering measurements indicate that irradiation cells should be short. Relative values of the energy required to form one ion pair (W) by 1‐MeV electrons are shown to be the same as those reported for lower energy electrons, and the following W values for the partial absorption of 1‐MeV electrons are reported with a probable error of about ±2%: C3H8 23.4, n‐C4H10 22.9, i‐C4H10 23.0, i‐C5H12 23.9, C3H6 24.8, 1‐C4H8 24.4, trans‐2‐C4H8 23.9, i‐C4H8 24.4, CH3CHO 26.4, (C2H5)2O 23.8, CO 32.2, SO2 30.4, NO 27.5, N2O 32.9, and NH3 26.5. Chemical‐yield measurements on ethylene suggest that the formation of acetylene can be measured with an accuracy of better than ±3%; above 400 Torr and with dose rates in the order of 1015 eV cc—1·sec—1 G(acetylene) = 3.07±0.08.

This publication has 20 references indexed in Scilit: