Measurements of energy spread of thermal field-emitted electron flow from tungsten

Abstract

The total energy spread of thermal field-emitted electron flows from an electro-chemically etched tungsten whisker is measured and compared with theoretically expected curves under constant emitted current densities, chosen with practical applications in mind. It is confirmed that the energy spread of thermal field-emitted electron flow is much wider than both cold field and thermal-emitted electron flows, as expected from the theoretical analysis.