Accession Number : ADA139015

Title :   Neutron Leakage from 'COMET' - A Duplicate Little-Boy Device.

Descriptive Note : Rept. for Sep-Oct 82,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)

Personal Author(s) : Robitaille,H A ; Hoffarth,B E

PDF Url : ADA139015

Report Date : Dec 1983

Pagination or Media Count : 45

Abstract : Fast neutron spectra between 600 keV and 10 MeV, directed outwards from the surface of the 'COMET' assembly, were measured using an NE-213 fast-neutron spectrometer at the Los Alamos National Laboratory. The COMET experiment, consisting of a duplicate Little-Boy device suitably modified for operation in the delayed-critical regime, was to provide improved energy and angular distributions of leakage spectra in support of efforts to re-evaluate ground doses from the Hiroshima bombing. Measurements were obtained at seven polar angles (from 0 to 135 degrees) and at two radii from the centre of the active volume (75 and 200 centimeters). These measurements were compared to two calculations available at the time of writing; one an earlier (1976) one-dimensional estimation and another more recent (1982) two-dimensional calculation, both based on Monte-Carlo techniques. Differences in high energy neutron leakage are apparent and probably due to dynamical considerations, as the theoretical calculations simulated the disassembling weapon itself, rather than the static experiments described herein. (Author)

Descriptors :   *Dosimetry, *Radiation dosage, *Nuclear radiation, *Neutron spectrometers, Neutron flux, Neutron scattering, Neutron transport theory, Fast neutrons, Nuclear binding energy, Nuclear energy, Yield, Bomb cases, Nuclear warheads, Models, Mathematical analysis, Spectrum analysis, Anisotropy, Bombing, Detonations, Measurement, Detectors, Monte Carlo method, Japan, Canada

Subject Categories : Radiobiology
      Numerical Mathematics
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE