One of the authors (ESK) and his students (Refs. 1-4) have, for several years, investigated system dynamics information contained in the gamma ray field emerging from an operating nuclear reactor core. Early experiments were directed along the lines of obtaining the sys-tem transfer function (frequency response). Either a driven perturbation or the natural noise generated in a neutron chain reaction represented the input to the system. The emerging gamma rays represented the system output. In later experiments, two highly collimated detectors were used to respond to the gamma rays generated in two narrow, intersecting channels through the reactor core. As with the earlier experiments, either a driven perturbation or natural noise phenomena can be used as dynamic system input. Selectivity in gamma ray energy detection and correlation of the two detector outputs yield information regarding the fission rate in the volume of intersection of the two channels under surveilance provided that the input process correlation is of dimensions on the order of (or smaller than) the volume of intersection.

Date Published: 1 August 1972
PDF: 6 pages
Proc. SPIE 0029, Imaging Techniques for Testing and Inspection, (1 August 1972); doi: 10.1117/12.978144

Published in SPIE Proceedings Vol. 0029:
Imaging Techniques for Testing and Inspection
John C. Urbach; Byron B. Brenden; Robert Apprahamian, Editor(s)