Ion-induced secondary electron emission from K-Cs-Sb, Na-K-Sb and Cs-Sb photocathodes and its relevance to the operation of gaseous avalanche photomultipliers

A. Lyashenko; A. Breskin; R. Chechik; T. H. V. T. Dias

doi:10.1063/1.3197063

paper

Ion-induced secondary electron emission from K-Cs-Sb, Na-K-Sb and Cs-Sb photocathodes and its relevance to the operation of gaseous avalanche photomultipliers

arXiv:0904.4881 · doi:10.1063/1.3197063

Abstract

The operation of visible-sensitive gaseous- and, to some extent, vacuum-photomultipliers is critically affected by secondary electrons originating from ion impact on the photocathode. A simple method for indirect measurement of the effective ion-induced secondary-electron emission (IISEE) coefficient from the photocathode into a gas medium, $γ_{+}^{e f f}$ was developed. The experimental results with visible-sensitive K-Cs-Sb, Na-K-Sb and Cs-Sb photocathodes, yielded $γ_{+}^{e f f}$ - values between 0.02 and 0.03 in Ar/CH $_{4}$ (95/5) at 700 mbar; these are in good agreement with theoretical calculations. The corresponding vacuum IISEE coefficients, $γ_{+}$ , were estimated, based on a theoretical model, to be 0.47, 0.49 and 0.47 for K-Cs-Sb, Na-K-Sb and Cs-Sb photocathodes, respectively. The ratio of gas $γ_{+}^{e f f}$ and vacuum $γ_{+}$ IISEE coefficients, calculated to be $\sim$ 0.06, is the fraction of secondary electrons surmounted the backscattering in the gas media.

arXiv comment10 pages, 10 figures, for submission to J. Appl. Phys; (2009) accepted

Ion-induced secondary electron emission from K-Cs-Sb, Na-K-Sb and Cs-Sb photocathodes and its relevance to the operation of gaseous avalanche photomultipliers

Abstract

References in corpus (5)

Cited by in corpus (4)