Accession Number : AD0668327

Title :   GAMMA RAY FIELDS ABOVE ROUGH CONTAMINATED SURFACES,

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s) : Bennett,Charles B. ; Kehrer,Willard S. ; Soule,Richard R. ; Corn,James P.

Report Date : 06 MAY 1968

Pagination or Media Count : 211

Abstract : An experiment was performed to determine the effect of surface roughness on the gamma radiation exposure rate above fallout-contaminated surfaces. Gamma radiation measurements were made at heights of 1, 4, 8, and 16 meters and at horizontal distances of 0 to 128 meters from the center of a 10 ft diameter circle of Au198 contamination on various surfaces, from plate glass to 5/8 in. gravel. Two supplemental tests were conducted with Lu177 contamination on plate glass and 5/8 in. gravel in an attempt to establish the energy dependence of the roughness effect. The measured values were numerically integrated to approximate the gamma exposure field above a uniformly contaminated infinite plane of the base material. For each surface material, the intensity of the gamma exposure field (in Roentgens per hour for a contamination density of 1 curie per square meter, r/hr per Ci/sq m was divided by the gamma intensity over a contaminated plate glass surface to obtain a surface roughness ratio for each of 4 heights. The 1-meter values are presented. (Author)

Descriptors :   (*GAMMA RAYS, INTENSITY), (*SURFACE PROPERTIES, *DOSE RATE), FALLOUT, SURFACE ROUGHNESS, RADIOACTIVE CONTAMINATION, EXPOSURE(PHYSIOLOGY), GOLD, SAND, GRAVEL, GLASS, DOSIMETERS, IONIZATION, RADIOACTIVE DECAY, MATHEMATICAL ANALYSIS, LITHIUM FLUORIDES, PARTICLE SIZE, MATERIALS, TABLES(DATA)

Subject Categories : Radioactiv, Radioactive Wastes & Fission Prod
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE