THE RADIATION ENVIRONMENT ABOVE AN AIR-GROUND INTERFACE COVERED WITH 60Co
Abstract
A review has been made of experimental and theoretical determinations of the buildup factor 3 feet above an infinite air-ground interface uniformly covered with 60Co. Experimental values of the buildup factor range from 1.15 to 1.38 and theoretically calculated values range from 1.15 to 1.23. A new series of Monte Carlo calculations is reported that tests various hypotheses which could account for this range of uncertainty. It is concluded that the substitution of compressed air or water for soil (required in the theoretical method of moments) is valid and that any intrinsic differences between the moments method and Monte Carlo techniques can account for no more than a 2 percent difference in the estimation of the buildup factor. A best value of 1.21 plus or minus .02 may be assigned to the buildup factor 3 feet above an infinite air-ground interface contaminated with 60Co. Angle and energy distributions of the photon number flux density for this geometry are also presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1968
- Accession Number
- AD0710985
Entities
People
- C. W. Garrett
Organizations
- Armed Forces Radiobiology Research Institute