Description: The availability of the Bevalac facility of energetic heavy ions with range greater than the size of small mammals makes possible the determination of the biological effects of relatively well defined high LET, whole body irradiation. With the increasing application of high-energy heavy ions in radiobiology there is a corresponding need to develop reliable techniques of both relative and absolute absorbed dose measurement. This paper describes dosimetry studies by the Health Physics Department of the Lawrence Berkeley Laboratory with activation detectors, ionization chambers, nuclear emulsion, thermoluminescent dosimeters and X-ray film. The application of these techniques to an experiment designed to study the leukemogenic effect of the whole-body irradiation of mice by 250 MeV/amu carbon ions is briefly described. Values of absorbed dose in tissue, obtained during this experiment, with a nitrogen filled ionization chamber and $sup 7$LiF thermoluminescent dosimeters are compared and shown to be in good agreement. As a result of this work a value for the average energy to produce an ion pair (W) in nitrogen by 250 MeV/amu $sup 6+$C ions of 37 +- eV was determined. Values of the efficiency of $sup 7$LiF relative to $sup 60$Co $gamma$-rays for ions with dE/dx in the range 110-260 MeV g$sup -1$ cm$sup 2$ are reported. (auth)
Date: August 30, 1975
Creator: Smith, A.R.; Stephens, L.D. & Thomas, R.H.
Partner: UNT Libraries Government Documents Department