Application of Fast Neutron Activation Analysis to Polymer Dosimetry

Abstract

Fast neutron activation analysis was used to measure the gamma dose absorbed by a polymer. A series of low density polyethylene films was irradiated by cobalt-60 gamma rays in the presence of air. The gamma 5 7 doses ranged from 1 x 10 to 4.7 x 10 rads. The oxygen content of the polymer films increased with increasing dose. The increase in oxygen content of each film was monitored at 1'720 em-l by infrared spectroscopy. The oxygen increase also was monitored by measuring the activation of oxygen-16. This latter method employs fast neutron activation of oxygen-16 and the measurement of the emitted radiation to determine gannna dose. The results of both methods of dosimetry are presented, and the improvements offered by the neutron activation technique are indicated.