Solid State Microdosimetry (invited paper)

Microdosimetry deals with the problem of identifying radiosensitive targets and obtaining the probability of energy deposition therein. Models of radiation action (biological or otherwise) may then be used to convert this information into observable quantities. As currently practised, microdosimetry is based almost entirely on gas phase methodology. This is because the main microdosimetric detector (a proportional counter) has, as active volume, tissue-equivalent (TE) gas. Important differences exist between gas phase and condensed phase microdosimetric spectra. This may have significant practical consequences, for instance when microdosimetry is used to calculate risk factors in radiation protection. It has thus become quite important to develop a TE solid state microdosemeter, and efforts in this direction are described. (author)