Sealed gaseous photomultiplier with CsI photocathode

A sealed gaseous photomultiplier tube (PMT) with a CsI photocathode has been developed using a micropattern gas detector (MPGD) made of Pyrex glass. A microblasting technique (MB) was employed for the production of a new hole-type MPGD. We investigated gaseous PMTs with a semi-transparent CsI photocathode for two different gas mixtures of Ne(90%)+i-C4H10 (10%) and Ne (90%)+CF4 (10%) at a gas pressure of 700 torr. Gains of up to 105 were attained with the microblasted glass plate (MB-GP) for both neon gas mixtures. Quantum efficiencies of up to 0.5% were obtained for UV light at the wavelength of 170 nm. The results of the aging test and the characteristics in a high magnetic-field environment are described for the gaseous PMT filled with neon gas mixture.