RESUMO
Objective To assess the retention of 241Am in the whole-body bone of worker by measuring the retention of 241Am in the skull. Methods A whole-body counter with high-purity germanium detector was used to measure the 59.5 keV full-energy peak count of 241Am in the skull. The efficiency of the measurement was calibrated by the digital skull phantom combined with the geometric model of the detector. The retention of 241Am in the worker’s skull was calculated. Results The proportion of skull dry weight relative to the whole-body bone dry weight was used as the coefficient to calculate the 241Am deposition in the whole-body bone from the measured activity of skull 241Am. Conclusion With the retention of 241Am in the skull and the proportion of skull dry weight, the retention of 241Am in the whole-body bone of the worker was calculated to be about 806 Bq.
RESUMO
Objective Based on the lanthanum bromide scintillator detector, the calculation method of G(E) function was developed to measure the air absorbed dose rate. Methods Firstly, the gamma energy spectrumof the lanthanum bromide detector were simulated and the response functions with different energies were determined with Monte Carlo simulation method. Then, the G(E) function was calculated by the least square method. Finally, the air absorbed dose rate measured by the lanthanum bromide detector using G(E) function conversion method was compared with the theoretical calculation value based on the point source experiments. Results The experimental verification results showed that the relative deviation between thecalculated value with G(E) function and the theoretical calculation value wasmostly controlled within ± 6%, which verified the accuracy of G(E) function. Conclusion The results showed that the method of G(E) function could be applied to calculate the gamma radiation dose rate based on the in-situ the gamma spectrum with LaBr3 detector.