Method and apparatus for multi element analysis based on neutron activation for this purpose, as well as a computer program product

摘要

A method for multi element analysis of a sample (1) on the basis of neutron activation, comprising the steps of: dividing the sample (1) into individual partitions (p1, p2, pn); generating of fast neutrons with an energy in the range from 10kev to 20mev with a neutron generator (11); irradiating the sample (1) with the neutrons, wherein the irradiation of the sample (1) in a continuous manner unpulsed takes place; measuring the from of the irradiated sample (1) gamma radiation emitted by a detector unit (16) with at least one detector (16a, 16b), wherein the measuring in an energy-sensitive manner during the irradiation takes place, where the measurement with respect to the partitions (p1, p2, pn) with the use of a collimator (17) takes place, and wherein at least prompt fluorescence or both prompt fluorescence and delayed gamma radiation is measured from the continuous neutron irradiation; evaluating the measured gamma radiation for determining at least one element of the sample (1), wherein the analyzing comprises determining the location - and energy resolved neutron flux within a respective partition (p1, p2, pn) of the sample (1) by numerical solution of a diffusion approximation of the linear boltzmann - equation, determining the mass percentage of the at least one element of the sample (1) in the individual partitions (p1, p2, pn) by releasing a linear system of equations, wherein the evaluation in an iterative manner with respect to the composition of the sample (1) is carried out so long until the calculated composition of the sample (1) no longer or only in a range of less than a predefined threshold value changes.