High current field emission from ZrC with differing cone angles

摘要

We briefly report on progress in forming field emitter array (FEA) cones from zirconium carbide. The major advances are on high current emission from single carbide emitters. These unique carbide materials have electron emission properties makingthem attractive for several applications. These could include video displays, microwave applications, high current and small spot electron sources (accelerators and FELs) and for operation at tube pressures or in poor vacuums (FEAs, vacuum detectors,neutralizing beams for ion thrusters, and charge dissipation on spacecraft).The significant recent outcomes are in high current electron emission from single emitters with and without extraction apertures. A new processing technique has been developed to allow in-situ sharpening of arced emitters. This method also yields largeemitter-cone half angles yet preserves the small emitter radii of electrochemically etched emitters. So far, this geometry translates into currents as high as 15 mA dc, the highest yet measured from single emitters, and enhanced beam confinement. Thisgeometry may also lead to new considerations in forming transition metal carbide emitter cones for FEAs.