The Basic LIC-concept

The entire ion chamber except the thin wires connecting the two electrodes are made from materials of low atomic number and density close to unity. This implies low perturbation of the radiation field when the chamber is used for absorbed dose measurements in tissue-like materials. The liquid mixture is matched to give a mass energy-absorption coefficient similar to that of water. The ion yield produced in the liquid volume is 300 times that of air. These qualities support a point-shaped sensitive volume design. In summary the ionization charge delivered by the chamber sensitive volume is proportional to the absorbed dose to water in the measurement “point” for a wide range of radiation-qualities and dose rates.