Neutron activation analysis to measure neutron flux using a standard sample vessel

摘要

A method for the non-destructive elemental analysis of large-volume samples using neutron radiation and a device for carrying out the method. In the method, the sample is irradiated with fast neutrons in a pulsed manner and the gamma radiation emitted by the sample is measured. The quantity of an element contained in the sample is evaluated after the background signal is subtracted from the area of the photopeak caused by the element in a plot of count rate versus energy. The gamma radiation emitted by a subregion of the sample, the composition of which is known, is evaluated in order to determine the neutron flux at the location of the sample. A metallic enclosure of the sample, such as a standardized waste container, can be selected as such a subregion, for example. A novel evaluation method based on multiparameter analysis can quantify, on the basis thereof, the presence of individual elements more quickly and more accurately than is possible according to the previous prior art. The device is characterized by a sample chamber, which is surrounded by a neutron-reflecting material, in particular graphite.