A new method for determining the efficiency of large-area beta sources constructed from anodized aluminum foils

A new method has been developed for determining the efficiency of large-area beta sources in anodized aluminum foils using transmission measurements. The method was applied to the efficiency measurement of a 90Sr-90Y large-area reference source. Measurement results show that the method can provide efficiency values for 90Sr-90Y reference sources with standard uncertainties smaller than 2.9%, which are far below the limit of 10% required by ISO 8769.