Electron Bombardment of Counting Diamonds

Abstract

THE response of six diamonds as conduction counters for α- or β-radiation was determined, using as a criterion the maximum pulse-height versus applied-field curve obtained under conditions of minimum polarization. Without removal from their holders, the diamonds were then exposed to electron bombardment from the 15 MeV. linear accelerator at St. Bartholomew's Hospital Medical College, the counting response being redetermined after each successive bombardment. The electron beam from the accelerator passed through a water collimator. The diamond holders were cooled by water, and the overall temperature of the diamonds was kept below 70° C. during the bombardment. Radioactivity induced in thin strips of copper was used for the routine electron flux dosimetry, the absolute flux estimates being obtained by comparison with calorimetry measurements.