Target scan parameters as they affect the performance of camera tubes

An analysis of target scan parameters as they affect the performance of electron-bombardment-induced-conductivity (EBIC) and photoconductive (PC) camera tubes is presented. The signal currents and the associated surface potentials are determined analytically as a function of the excited target resistance, beam current, and the secondary emission characteristics of the target surface. Experimental techniques for measuring the pertinent parameters by application of this analysis are described, and characteristic data for PC and EBIC-type camera tubes presented. The effect of these parameters on the signal-to-noise ratios and ultimate resolving capabilities of these types of camera tubes are compared with similar data on image orthicon type tubes.