Technique for light collection in Cherenkov or scintillation counters

The authors describe a method of collecting light in Cherenkov or scintillation counters which involves the use of hollow light guides having reflecting internal walls and filled with a liquid or gaseous medium. In order to increase the effectiveness of light collection near the radiator and to cool the parts near the light collector a temperature gradient is produced which increases the refraction coefficient of the medium in the direction of the light collector. The authors suggest using as media: gases, mixtures of gases, liquid with vapour at nearly critical pressures and at temperatures approaching criticality close to the phase boundary liquid and its vapour mixed with gas, mixtures of liquids and solutions of salts in liquids