Non-linear effects in gas ionization detectors

Full text: Nuclear physics and nuclear techniques of analysis commonly employ gas ionization detectors for heavy ion detection. The response of these detectors has been shown, however, to be non-linear with atomic number, mass and energy. Even the lightest ions such as carbon and oxygen are not unaffected. This can have significant implications for accurate energy spectroscopy using these detectors. Considerable progress on a detailed study of gas ionisation detector response, performed at the ANU, will be presented. Key features will be discussed and a universal empirical formula developed to predict gas detector response will be presented. Interesting new developments in the investigation of the fundamental processes occurring in the detector will also be reported, including the results of experiments to measure the pressure dependence of the detector response