OPTIMUM X-RAY YIELDS IN BETA-EXCITED X-RAY SOURCES
Abstract
An investigation was conducted to systematically investigate the influence of source physical conditions on the characteristic X-ray yield in beta-excited X-ray sources. The K X-ray yield excited by beta-particles in various target materials increased with increasing target thickness up to a maximum, after which the yield decreased because of X-ray absorption by target material. Optimum K X-ray yields were noted for P32 beta-particles at target thicknesses of about 77, 180, and 280 mg/sq cm, respectively, for Sn, Ta, and Pb targets. Sn, Ta, and Pb target thicknesses of about 80,205, and 310 mg/sq cm, respectively, were found to give optimum K X-ray yields for Sr90 - Y90 betas. The K X-ray intensities were increased by from 110 to 160 percent by the addition of source backing of same thickness as that providing maximum X-ray yields. Increase of backing to a thickness greater than that required to absorb maximum beta energies further increased maximum X-ray intensities from 25 to 50 per cent. Increased K X-ray yield efficiency extends the use of these sources to certain practical applications in low energy region (below 100 kev) where no suitable gamma-emitting isotopes presently exist. It is recommended that source physical conditions presented in this study be used, along with image intensifying systems, to extend the possible use of beta-excited X-ray sources to certain practical applications where increased X-ray intensity is desired.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 27, 1958
- Accession Number
- AD0806436
Entities
People
- A. T. Krebs
- J. G. Kereiakes
- O. E. Weir
Organizations
- United States Army Medical Research Laboratory