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External field enhanced photoemission in silver-cesium-oxygen photocathodes
Abstract:
Reduction in the surface barrier of silver-cesium-oxygen photocathodes by the application of high external electric fields has been demonstrated by the extension of the photoelectric threshold. Photocurrent for selected wavelengths as a function of field strength have been fitted to Schottky plots; however, the observed shifts in photoelectric threshold are not consistent with this theory. Photoyield increases near threshold of five times have been observed for fields of 10(4) V/cm. In addition, data of thermionic emission as a function of photoelectric threshold and cathode temperature are presented along with a discussion of these parameters and their effect on optimum signal-to-noise ratio.
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