Apparatus for analyzing the spectral data in an elemental analyzer

Abstract

An apparatus for analyzing the spectral data in an elemental analyzer measuring gamma rays arising from neutron capture in bulk substances is disclosed. The formation of optimally-weighted linear sums of the number of counts in various portions of the energy spectrum of neutron-capture gamma rays improves measurement accuracy in an apparatus for on-line elemental analysis of bulk substances. Within the apparatus, the analyzed bulk substance is exposed to neutrons, and neutron capture generates prompt gamma rays therefrom. A detector interacts with some of these gamma rays to produce electrical signals used to convert their energy spectrum to digital form by pulse-height analysis. A small computer uses this digitized spectrum to construct the weighted linear sums corresponding to at least one interesting element. Generally, several elements are measured, and the computer forms ratios between the elemental sums to provide relative concentration measurements which are independent of absolute counting rates. The instrument also contains a calibration plug to verify performance, a digital data link to allow the computer to be remote from the gamma-ray detector and devices to display the results of the measurement and/or to communicate them to external equipment. Measurement of an element principally present in the instrument structure permits the computer to correct the measurement of an interesting element in the bulk substance for its presence in the structure.