Application of a multi-element beta dosimeter

A passive beta dosimeter has been developed at the Pacific Northwest Laboratory (PNL) to more accurately account for the beta energy distribution in the radiation field. This dosimeter uses TLD chips placed under shields of varying thicknesses. Each shield attenuates the beta radiation to some degree, depending on the thickness of the shield. An indication of the beta energy spectum can therefore be obtained by examining the relative responses of the TLDs under the different shields. This indication of the spectrum allows the selection of the appropriate energy-dependent calibration factor for converting TLD response to dose. A number of these multi-element dosimeters have been exposed in unknown fields of mixed gamma and beta radiation, and doses for both radiation components have been determined