Response of Panasonic dosimeters to submersion exposure by 133Xe

The dose response to 133Xe radiation of several types of Panasonic 800 series thermoluminescent dosimeters (TLD) were evaluated. The dosimeters were exposed by submersion in 133Xe gas. The relative sensitivities of the lithium borate and the calcium sulfate phosphors were determined for several configurations. The TLDs were exposed in the holders (as the devices came from the vendor) with various shields covering the elements, and they were exposed with the TLDs removed from the holders. Some dosimeters were exposed, both in holders and out of holders (TL insert only configuration), both in plastic bags and free in air. For the in-holder configuration, the responses of the heavily shielded (greater than 170 mg cm-2) elements were used to obtain the photon dose-rate component, and the responses of the lightly shielded (less than 13 mg cm-2) element were used to obtain the beta component. Similarly, for the insert-only configurations, the observed over-response of the calcium sulfate phosphors to low-energy photons could be used to separate the beta dose rate component. By using the calculated beta doses, correction factors were determined for the apparent under-responses of the elements to beta radiation. The results of both methods are consistent. These results also suggest that the beta component could be used in environmental monitoring as a more sensitive means to determine 133Xe activities in clouds and to separate some of the effects of submersion exposure from those of distant exposure.