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内容記述 |
Am-241 sources are used for radiation protection meter calibrations, the radiation quality being denoted as S-Am. Because the low energy photon contribution to the fluence spectrum varies due to different source encapsulations, currently, conversion coefficients from air kerma to dose equivalent (CC) need to be determined by spectrometric measurements. In this work, we propose using additional filtration with the S-Am, making the CCs independent of the source encapsulation and allowing the use of generic CCs without the necessity to use spectrometry. The effect of different filter materials on the CCs was studied by Monte Carlo simulations, and validated by spectrometric measurements. The recommended added filtration is 0.25 mm of copper and 0.4 mm of aluminum, and generic CCs that can be used with this filtration are given. In addition to the CCs being insensitive to encapsulation thickness, issues with energy response of detectors related to differing X-rays production between different S-Am beams are solved by the added filtration, and therefore the authors recommend using the added filtration in all Am-241 calibration beams. |
