The NSWC microchannel electron source program

The microchannel electron source is currently being developed at the Naval Surface Warfare Center for cold cathode applications which require high repetition rates and short pulse widths. It is based on microchannel plate principles which, in general, allow for fast response times. However, the microchannel plate is generally limited to output currents of less than 10⁻⁴ A/cm². We describe a method to increase the output current from a microchannel device by several orders of magnitude. Our analysis has shown that one can obtain channel current densities of order 1 A/cm² by constructing the device from a crystalline bulk semiconductor. Carrying the analysis further suggests that current densities can be increased by another order of magnitude by incorporating an appropriate electron injection scheme. Important analytical results, as well as the present status for the fabrication of a proof-of-principle device, are discussed.