A new processing technology and the properties of multialkali antimonide photocathodesare described.The technique requires an initial antimony layer to be deposited on a fiber-optic window at asuitable temperature.Aft...A new processing technology and the properties of multialkali antimonide photocathodesare described.The technique requires an initial antimony layer to be deposited on a fiber-optic window at asuitable temperature.After that.the layer is activated by multialkali and antimonide.Thus.the multialkaliphotocathodes named“The Modern Multialkali Photocathode”are obtained.It has been found that aphotocathode thus processed gives a sensitivity of 200 to 300μA/Im for white light at a color temperature of2854K.This paper shows the variation of photosensitivity during processing of a Modern MultialkaliPhotocathode and the variatioon of spectral sensitivity at different wavelengths.The author discusses theresults.gives a supposition of“photoemission center”,and discusses the role of Cs in multialkaliphotocathodes.展开更多
In this paper a negative electron affinity （NEA） multialkali photocathode of （Na<sub>2</sub>KSb-Cs）-O-Cs structure is fabricated by new technology. It is found that its emission stability is much bette...In this paper a negative electron affinity （NEA） multialkali photocathode of （Na<sub>2</sub>KSb-Cs）-O-Cs structure is fabricated by new technology. It is found that its emission stability is much better than that of the NEA GaAs photocathode, but is inferior to that of the conventional Na<sub>2</sub>KSb（Cs）. After 70 hour performance in a pumping vacuum system, the emission sensitivity of the NEA （Na<sub>2</sub>KSb-Cs）-O-Cs photocathode drops only by 2.5%. The emission stability is closely related to the states of the activation cesium and oxygen during activation, best results being obtained with cesium ions and excited oxygen. Furthermore, better photoemission sensitivity and emission stability may be obtained if the cathode is illuminated by intense white light during the activation process. The performance of the NEA （Na<sub>2</sub>KSb-Cs）-O-Cs cathode which has not been illuminated by intense white light during activation may be improved by the illumination even during operation intermission.展开更多
文摘A new processing technology and the properties of multialkali antimonide photocathodesare described.The technique requires an initial antimony layer to be deposited on a fiber-optic window at asuitable temperature.After that.the layer is activated by multialkali and antimonide.Thus.the multialkaliphotocathodes named“The Modern Multialkali Photocathode”are obtained.It has been found that aphotocathode thus processed gives a sensitivity of 200 to 300μA/Im for white light at a color temperature of2854K.This paper shows the variation of photosensitivity during processing of a Modern MultialkaliPhotocathode and the variatioon of spectral sensitivity at different wavelengths.The author discusses theresults.gives a supposition of“photoemission center”,and discusses the role of Cs in multialkaliphotocathodes.
基金This work is supported by the Natural Science Foundation of Fujian Province, China.
文摘In this paper a negative electron affinity （NEA） multialkali photocathode of （Na<sub>2</sub>KSb-Cs）-O-Cs structure is fabricated by new technology. It is found that its emission stability is much better than that of the NEA GaAs photocathode, but is inferior to that of the conventional Na<sub>2</sub>KSb（Cs）. After 70 hour performance in a pumping vacuum system, the emission sensitivity of the NEA （Na<sub>2</sub>KSb-Cs）-O-Cs photocathode drops only by 2.5%. The emission stability is closely related to the states of the activation cesium and oxygen during activation, best results being obtained with cesium ions and excited oxygen. Furthermore, better photoemission sensitivity and emission stability may be obtained if the cathode is illuminated by intense white light during the activation process. The performance of the NEA （Na<sub>2</sub>KSb-Cs）-O-Cs cathode which has not been illuminated by intense white light during activation may be improved by the illumination even during operation intermission.
