Abstract
High and reproducible gains were obtained from thin films of CsI deposited on tantalum substrates. The most probable energy of emission of the secondary electrons emitted from CsI dynodes was determined to be or=300 degrees C. Exposure to dry air did not harm the dynodes: however, the gain of the dynodes decreased when they were exposed to humid air. A demountable electron multiplier incorporating CsI dynodes was assembled under normal laboratory ambient. The stage-gain was found to be higher than that of conventional alloy dynodes. A great advantage of this multiplier lies in the fact that it can be easily rejuvenated to give reproducible overall gain.