The SEC Target

Abstract

Publisher Summary This chapter describes the secondary electron conduction (SEC) target and outlines its salient features. With the SEC target it has been possible to develop camera tubes with many outstanding performance characteristics. These tubes have the combined advantages of direct beam read-out, long integration and storage times, and sensitivity approaching that of a thin-film image orthicon. The purpose of this chapter is to discuss, in quantitative terms, the target parameters of interest in most camera tube applications. Several other characteristics, important in some applications, are worth noting. The SEC target has been operated successfully at ambient temperatures of from -70°C to +l00°C. It can also withstand severe vibration. Recently, targets have been vibrated at acceleration levels of 30 g without damage. Another characteristic that should be considered is halation. When the image orthicon is driven into saturation by an intense signal, secondary electrons returned to the target can land on areas surrounding the bright signal and produce a black halo. In applications involving the detection of static, low light-level scenes, the ability to integrate for long periods is extremely useful. The long integration times possible with the SEC target are, perhaps, its most outstanding feature.