THE PROSPECTS OF USING LARGE VACUUM PHOTODIODES WITH GAS SCINTILLATION PROPORTIONAL COUNTERS

摘要

The large quartz PMTs needed are expensive, bulky, fragile, often have long term instabilities, and are available only in a limited number of sizes. The largest such tube available has a photocathode of only 11 cm diameter.nThe advantages of photodiodes are that they can be made less expensively than PMTs, they are compact, rugged, and very stable. Unfortunately, the commercially available photodiodes are small and have peak quantum efficiencies of 20% or less. Thus, they are not yet competitive with PMTs.