Unattended Mode Monitoring of Neutron Coincidence Data and High Resolution Gamma-Ray Spectra

Year
1991
Author(s)
B. G. R. Smith - Commission of the European Communities
F. Van Der Straat - Commission of the European Communities
G. Ballette - Commission of the European Communities
Abstract
Two simple low cost flexible solutions are presented, one for the unattended acquisition of neutron coincidence data, the other for the unattended acquisition of gamma-ray spectra. The first solution consists of an inexpensive commercial data logging equipment attached to a neutron coincidence electronics for the unattended acquisition of passive neutron coincidence data. The data logger permits both the flexible configuration of a passive neutron coincidence measurement system for unattended mode monitoring and the storage of the measured totals and reals count rates. A custom software package permits the complete analysis of the stored data to provide an assay of each item passing through the measurement cavity. The analysis includes an input for different isotopic compositions, the calculation of the multiplication corrected reals rates, and the determination of 240,Pu'eff. masses. The software package for review includes displays of the totals and reals count rates logged by the data logger, the multiplication corrected reals count rates and the measured Puf f masses, all as afunction -of time. The second solution consists of a simple low cost flexible software package controlling up to 4 multichannel analyzer (MCA) cards for unattended spectrum acquisition. The software permits the independent configuration of up to 4 MCA cards for different monitoring cycles and for different spectrum acquisition cycles each being based upon different trigger criteria. In this way spectra corresponding to different events are automatically identified, time tag, acquired, and stored for subsequent evaluation. An additional feature permits to run, in batch mode, the Multi-Group Analysis (MGA) software package for the determination of the plutonium isotopic composition. An application of both these solutions will be presented and the results discussed.