Non-polar liquids as detection media in radiation detectors

In this key-note lecture we summarize briefly the physical and chemical properties which make non-polar liquids suitable as detection media for liquid ionization chambers. For fast detectors, a high electron mobility and a high ionization yield are necessary while for slower ionization chambers and imaging detectors, liquid with smaller electron mobilities and ionization yields are tolerable. In liquefied rare gases, the collected charge can be increased by converting excitation light into charge carriers by photoionization of solutes. In liquid xenon, charge carrier multiplication by electron avalanches is possible. The limitations of these two internal amplification processes is discussed.