RADIATION-FIELD MAPPING OF INSECT IRRADIATION CANISTERS

Dosimetry methods developed at NIST for mapping ionizing radiation fie lds were applied to canisters used in Cs-137 dry-source irradiators de signed for insect sterilization. The method of mapping the radiation f ields inside of these canisters as they cycled through the gamma-ray i rradiators involved the use of radiochromic films, which increase in o ptical density proportionately to the absorbed dose. A dosimeter film array in a cardboard phantom was designed to simulate the average inse ct pupae density and to map the dose within the full volume of the can ister; the calibrated films were read using a laser scanning densitome ter. Previously used dosimetric methods did not allow for the spatial resolution that is possible with these films. Results indicate that th is dose-mapping technique is a powerful method of evaluating a variety of radiation fields of commercial radiation sources, with promising a pplications as a means of dose validation and quality control. Copyrig ht (C) 1997 Published by Elsevier Science Ltd