Recent Developments and Applications of the SEC-vidicon for Astronomy

Publisher Summary This chapter elaborates the developments and applications of the secondary electron conduction (SEC)-vidicon for astronomy. The engineering development of the SEC-vidicon as an astronomical sensor has continued at Princeton University Observatory in parallel with its operational use. The developmental effort includes the enhancement of the basic attributes that make the SEC-vidicon an appropriate sensor—namely, high quantum efficiency, low threshold, long integration time, and also work to broaden its scientific usefulness, such as, the development of a magnesium fluoride photocathode window for vacuum-ultraviolet sensitivity, and a permanent-magnet focus assembly for thermal compatibility, with proposed large space-telescopes. The entire tube including the image section is magnetically focused by immersion in an 80-G axial magnetic field. The use of a magnetically focused image section is required to maintain high modulation transfer function over the image format and to have the plane photocathode. It is found that the photocathode dark current and other background emissions within the image section are strongly influenced by temperature.