Matrix effects correction on (sup 252)Cf shufflers by application of the alternating conditional expectation to neutron flux monitor data

摘要

The (sup 252)Cf shuffler assays fissile uranium and plutonium using active neutron interrogation and then counting the induced delayed neutrons. Using the shuffler, we conducted over 1700 assays of 55-gal. drums with 28 different matrices and several different fissionable materials. We measured the drums to diagnose the matrix and position effects on (sup 252)Cf shuffler assays. The matrices incorporated metals, neutron poisons, and hydrogen in densities ranging from 0(le) (sub pH) (le) 0.086 g/cm(sup 3), a range of cases more extreme than typically found in routine plant use. We used several neutron flux monitors during irradiation and kept statistics on the count rates of individual detector banks. The intent of these measurements was to gauge the effect of the matrix independently from the uranium assay.