A Method for Calibration of Cylindrical Tissue Equivalent Proportional Counters

A computer simulation technique was used to generate estimates of the pulse height distribution arising from (n, p) reactions in a cylindrical tissue equivalent radiator. The model assumes a mono-directional neutron beam interacts at a point on the cylinder and the resulting protons completely traverse the tissue equivalent gas volume. Features in the simulation model spectrum are correlated to spectral features produced by an experimental TEPC irradiated by an isotopic neutron source. Model predictions are also compared to actual spectra produced by using proton beams from a cyclotron. These three estimates for the energy calibration of the cylindrical TEPC are in good agreement. A simple method for energy calibration of cylindrical TEPC´s will facilitate measurement of absorbed dose and dose equivalent due to neutrons. The use of TEPC based instruments would permit the refinement of personnel neutron dosimetry programs as performed for the nuclear power industry, medical neutron therapy, and research laboratories using radio-active sources.