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Title: Fieldable computer system for determining gamma-ray pulse-height distributions, flux spectra, and dose rates from Little Boy

Conference ·
OSTI ID:5554037

Our system consists of a LeCroy 3500 data acquisition system with a built-in CAMAC crate and eight bismuth-germanate detectors 7.62 cm in diameter and 7.62 cm long. Gamma-ray pulse-height distributions are acquired simultaneously for up to eight positions. The system was very carefully calibrated and characterized from 0.1 to 8.3 MeV using gamma-ray spectra from a variety of radioactive sources. By fitting the pulse-height distributions from the sources with a function containing 17 parameters, we determined theoretical repsonse functions. We use these response functions to unfold the distributions to obtain flux spectra. A flux-to-dose-rate conversion curve based on the work of Dimbylow and Francis is then used to obtain dose rates. Direct use of measured spectra and flux-to-dose-rate curves to obtain dose rates avoids the errors that can arise from spectrum dependence in simple gamma-ray dosimeter instruments. We present some gamma-ray doses for the Little Boy assembly operated at low power. These results can be used to determine the exposures of the Hiroshima survivors and thus aid in the establishment of radation exposure limits for the nuclear industry.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Technical Programming Services, Pleasanton, CA (USA)
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
5554037
Report Number(s):
LA-UR-83-3349; CONF-840202-5; ON: DE84003829
Resource Relation:
Conference: 17. midyear topical meeting of the Health Physics Society, Pasco, WA, USA, 5 Feb 1984
Country of Publication:
United States
Language:
English