CONCENTRATING LIGHT-GUIDE FOR A THRESHOLD CHERENKOV COUNTER

A procedure for fabricating a light guide (Winston lens) which increas e the effective light-collecting area of the light detector (the catho de diameter is 45-120 mm) and extends the angle range when registering radiation in threshold Cherenkov counters is described. The concentra ting light guide, which may be 300 mm high and wide, were made by stre tching from a sheet of organic glass 3-5 mm thick by the method of pne umatic (vacuum) formation. The coefficient of light reflection from th e surface of a spray-coated light guide is plotted as a function of wa velength in the range 185-650 mm.