About the effectiveness of spectrometry in alpha-activity monitoring of industrial air-borne particles

The maximum-likelihood method (MLM) is applied for the analysis of the background compensation problem when using alpha-spectrometry to measure the transuranium radionuclide (TRU) content in thick aerosol samples. It is shown, that the uncertainty of the measurement results has a rather small dependence on the digit capacity of the analog to digital converter (ADC). For the total TRU alpha-activity measurement a 7-bit conversion in the energy range up to 9–10 MeV is sufficient to evaluate the background parameters in the energy region of interest (ROI). Background compensation is also made by subtraction of the estimated total background from the sum of counts measured in the ROI.