Secondary electron conduction in low density targets for signal amplification and storage in camera tubes

The performance of a camera tube, especially its sensitivity, can be improved by employing a means of multiplying the electronic charge emitted by the photocathode prior to storage and the subsequent scanning for readout. One possible method of achieving such a pre-beam gain is the efficient and lagless conversion of high energy electrons into a larger number of low energy electrons. Based on this approach a new type of storage target for use in camera tubes has recently been developed at the Westinghouse Research Laboratories. This target operates on the principle of Secondary Electron Conduction (SEC) through a low density layer of an insulator under excitation of KeV-electrons. The effect is described and the performance of the SEC target is evaluated with respect to conventional television requirements as well as the requirements of low light level imaging.