Field Experience of Using E-PERM@ Integrating Electret Ion Chambers for Monitoring Perimeter Gamma Radiation Levels
P. Kotrappa, L. R. Stieff
The E-PERM Electret ion chamber (EIC) is a passive integrating ionization monitor consisting of a stable electret (a charged Teflon disk) mounted inside a small (58 ml) chamber made of electrically conducting near tissue equivalent plastic. The electret serves both as a source of electric field and as a sensor. The ions produced inside the chamber are collected onto the electret, causing a reduction in charge. The reduction in charge, measurable with a portable electret reader, is related to the gamma radiation level and the exposure time. The purpose of this presentation is to review publications, which compare the performance of these devices relative to TLD (thermoluminescent dosimeter) and HPIC (high pressure ionization chamber) gamma monitors. The paper analyzes the field experiences including advantages, disadvantages, cost, performance, te robustness and other features relative to TLD. It is concluded that these provide cheaper and better alternative to the TLD monitors currently used in environmental perimeter gamma monitoring program.
This abstract was presented at the 33rd Annual Midyear Meeting, "Instrumentation, Measurements, and Electronic Dosimetry", Poster Session, 1/30/2000 - 2/2/2000, held in Virginia Beach, VA.