Ramp mode operation of a pyroelectric vidicon

A new mode of operating a pyroelectric vidicon is demonstrated. It uses a linearly rising voltage ramp applied to the target connection to generate the positive bias across the target necessary for efficient tube operation. The theoretical relationship between lag (time response of the tube to a step impulse signal) and readout efficiency is examined. Lag measurements of a tube operating in ramp mode are used to find the readout efficiency under different operating conditions, and the importance of the beam energy spread of the electron gun in determining the operating efficiency is emphasized.