BETA-RAY AND GAMMA-RAY ENERGY OF RESIDUAL CONTAMINATION

Technical Report · Tue Apr 01 04:00:00 EST 1952

OSTI ID:4231727

Tochilin, E; Howland, P R; Fitch, S H; Golden, R; Barrett, J T

By means of depth-dose measurements, obtained using photographic film packets, a study was made of the beta-ray energy and thc ratio of beta- to gamma- ray ionization resulting from residual contamimation following the surface and underground shots of Operation JANGLE. Measurements were also made of the residual gamma-ray energy. Readings of gamma-ray energy which were made with a group of modified ionization chambers and survey instruments calibrated to effective x-ray energies over a range from l65 to 1,200 kev, indicated the energies to vary between 84 and 140 kev for the surface shot and between 113 and 144 kev for the underground shot. To determine the effective energy of prompt gamma radiation plus base surge radiation chambers were placed in the field prior to each shot and exposed to 113 radiations from time zero to approximiately H + 3 hr. These measurements showed the energy to range between 430 and 565 kev for the surface shot and between 376 and 430 kev for the underground shot. Using photographic film packets the equivalent maximum beta energy measured in close proximity to the early-time fall-out contamimation for the surface shot was no greater than 1.7 Mev. This energy was an average over a period of 24 hr following the surface shot. Additional measurements of this energv at 18 in above the contaminated ground surface gave a value of 2.0 Mev. Equivalent maximum betaenergy measurements in close proximity to the earlytime fall-out contamination for the underground shot gave a value no greater than 2.0 Mev when averaged over a period of 70 hr following the shot. Measurements at 18 in. above the cortamination gave a value of 1.7 Mev. The maximum ratio of beta-to-gamma tonization measured with film packets located in highly contamimated areas was 14 for the surface shot and 24 for the umderground shot. (auth)

• Research Organization: Naval Radiological Defense Lab., San Francisco
• NSA Number: NSA-13-022236
• OSTI ID: 4231727
• Report Number(s): WT-345
• Country of Publication: United States
• Language: English

Related Subjects

BETA PARTICLES
CONTAMINATION
ENERGY
ENERGY RANGE
FALLOUT
GAMMA RADIATION
HEALTH AND SAFETY
INSTRUMENTS
IONIZATION
IONIZATION CHAMBERS
MEASURED VALUES
MONITORING
NUCLEAR EXPLOSIONS
PHOTOGRAPHIC FILM DETECTORS
PROJECT JANGLE
RADIATION DOSES
SOILS
STANDARDS
SURFACES
TESTING
X RADIATION