A PM of New Design for High Speed Physics

Abstract

Total transit time of the order of 1 ns with a standard deviation less than 0.1 ns, IR* better than 0.3 ns FWHM** are typical characteristics of a new type of PM designed and developed at LEP. These performances are obtained with the following applied voltages: between photocathode and oultiplier entrance :1 KV ; across the multiplier: 1 KV to 1.5 KV ; between multiplier output and collector : 2 KV The overall dimensions of the tube are maximum. diameter 40 mm, length 80 mm. The paper explains how these performances are achieved, due to a new design, comapared to the classical approach of PM. The predicted data, deduced from a computer programme (dealing with electron multiplication in channels) are compared to the experimental figures obtained from a coincidence study through a short pulse source, a time to amplitude converter and a multichannel analyzer. Some typical applications are evoked such as : high energy; physics, quantum. electronics.