Accession Number : AD0276926

Title :   THE EFFECT OF BORON-10 SHIELDS ON THE CALIBRATION OF NEUTRON-THRESHOLD DETECTORS

Corporate Author : ARMY NUCLEAR DEFENSE LAB EDGEWOOD ARSENAL MD

Personal Author(s) : MCNEILLY,JOHN H. ; KINCH,JOHN W.

Report Date : SEP 1961

Pagination or Media Count : 1

Abstract : The threshold-detector system is calibrated by exposing bare foils to a known neutron flux. When measuring an unknown neutron source, these calibrated foils are exposed in boron-10 shields. The effect of these shields on the measured flux and spectrum is discussed. The results include comparison of data obtained from threshold detectors exposed to a neutron field: (1) in a steel sphere whose periphery is filled with boron-10; (2) in a pressed and sintered boron-10 shield; (3) in a cadmium capsule; and (4) unshielded. There was no significant difference between results obtained from threshold detectors exposed in a pressed and sintered boron-10 shield and the results obtained from threshold detectors exposed in a steel sphere with a boron-10 periphery. The cadmium container and spacers that hold the threshold detectors in the boron-10 shield have no significant effect on the measured neutron flux and spectrum. There is a measurable effect of the boron-10 shield on the neutron flux and spectrum as detected by the threshold detectors within the shield. A 30% neutron-attenuation factor is observed for the sulfur-threshold detector. (Author)

Descriptors :   *BORON, *NEUTRON FLUX, DETECTORS, FOILS(MATERIALS), MEASUREMENT, RADIATION MEASURING INSTRUMENTS, SHIELDING, SINTERING

Distribution Statement : APPROVED FOR PUBLIC RELEASE