Large photocathode detectors for large calorimetry

The authors discusses techniques to make inexpensive large-area S-11 equivalent (QE 10-15%) photocathodes in spherical, cylindrical and planar geometries in a typical laboratory. Novel techniques to obtain photoelectron gain (*10-1000) using gas amplification and using fast phosphor photoelectron gain in large cylindrical geometries with uniform collection efficiency and relatively low time spread are demonstrated. Examples and properties are presented of working devices with areas up to 2500 cm/sup 2/, which can be scaled to arbitrarily large sizes, especially in cylindrical geometries. Performance data, applications, costs, and limitations and advantages of these devices are presented. Possibilities for a novel fiber-optic output phototube and a barium fluoride phototube are presented.<
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