The Los Alamos thermoluminescence dosemeter badge

The Los Alamos thermoluminescence dosemeter (TLD) provides an accurate and versatile instrument for the measurement of ionizing radiation and is capable of passing the Health Physics Society Standard, ''Criteria for Testing Personnel Dosimetry Performance''. For photons above 100 keV in energy, the badge can measure dose without the need of correction factors. However, below 100 keV correction factors are necessary but the badge can be used as a crude spectrometer to estimate the photon energy and thus the appropriate correction factors. For a mixture of low and high energy photons, an average energy is obtained that varies with the mixture. Low energy photons can be distinguished from beta rays. For a mixture of 90Sr beta and 60Co gamma radiation, the fraction of each component can be determined and appropriate correction factors applied. To evaluate neutron doses, the badge reading must be supplemented with a knowledge of the source and moderating material, or on-site determination of correction factors. (author)