Numerical calculations of time-dependent charge distributions are presented and compared with distributions measured on radiation-charged electrets made of thin polymer films, which are charged and discharged in a Radiation-Charged Electret Ionization Chamber (REIC) through the application of ionizing radiation. The chamber resembles a parallel plate ionization chamber, and has a thin film of polymer covering the collector and guard-ring electrodes. Calculations are performed by solving Laplace's Equation for the true geometry of the charging/discharging set-up, then applying estimates of ion-density distributions generated from known scattering distributions and/or simpler approximations. Measurements of radiation induced conductivity (RIC) are presented and fitted to an empirically derived analytical model, and the effects of RIC on the operation of a radiation dosimeter based on the electret are investigated and discussed. Short-term and long-term charge decay from the electret is measured and fitted to a previously developed model. The effects of post-charging heat treatment of the radiation-charged electret are presented and discussed. Lastly, the dosimetric characteristics of the REIC are considered in light of those physical aspects investigated here.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41698 |
| Date | January 1994 |
| Creators | MacDonald, Brennan A. |
| Contributors | Fallone, B. Gino (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001403706, proquestno: NN94676, Theses scanned by UMI/ProQuest. |
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