Accession Number : ADA137496


Title :   Spectrum-Averaged Kerma Factors for Reactor Dosimetry with Paired Ion Chambers.


Descriptive Note : Technical rept.,


Corporate Author : ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD


Personal Author(s) : Ferlic,K P ; Zeman,G H


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA137496


Report Date : Sep 1983


Pagination or Media Count : 32


Abstract : Neutron and gamma spectrum-averaged kerma factors (SAKF's) were calculated for four reference spectra and 18 configurations of the AFRRI TRIGA reactor for materials of interest in dosimetry applications. Reactor gamma SAKF ratios for tissue to carbon and for tissue to magnesium (ion chamber wall materials) gave average values + or - 2 standard deviations of 1.13 + or - 1% and 1.09 + or - 3%, respectively. For some reactor configurations, the gamma SAKF ratios were as much as 7.6% different from corresponding values for cobalt-60 gamma rays. Reactor neutron SAKF ratios for ICRU (International Commission on Radiation Units and Measurements) muscle to ion chamber gas materials were as follows: TE (tissue-equivalent) gas, 0.983 + or - 0.5% for all configurations; carbon dioxide, 9.8 + 10%; and argon, 71 + or - 27%. At depth in a phantom, the neutron SAKF for ICRU muscle differed substantially from the free-in-air value for the same reactor configuration. This finding suggests the need for more thorough spectrum determinations in anatomical phantoms and for more sophisticated dosimetric tools to better quantitate the dose deposition process.


Descriptors :   *Kinetic energy, *Dosimetry, Ionizing radiation, Gamma rays, Radiation absorption, Radiation dosage, Irradiation, Neutrons, Ionization chambers, Computations, Spectra, Gamma ray spectra, Equations, FORTRAN, Computer programs, Muscles, Tissues(Biology), Measurement


Subject Categories : Radiobiology
      Nuclear Physics & Elementary Particle Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE