Abstract: A thermionic electric converter includes a cathode output enhancing laser (374) operable to direct a laser beam (376) to strike an emissive surface of a cathode emitter (321), to increase the electron output of the cathode emitter (321). The cathode output enhancing lase (374) is positioned to direct a laser beam (375) through an opening (370) in the anode (306) or target structure, in the direction of the cathode emitter (321). An electron repulsion ring (380) is provided at an edge of the opening (370) in the anode (306), to reduce the number of electrons missing the anode (306) and passing through the opening (370) in the anode (306).

Abstract: An improved thermionic electric converter uses a wire grid cathode to provide a larger surface area for electrons to boil off. Alternately or additionally, the larger electron emission surface area can be achieved by using a curved electron emission surface. A laser provides quantum interference to electrons just before they reach the anode, thereby lowering their energy levels such that they more readily are captured by the anode. The arrangement provides improved conversion efficiency and reduced electron scatter.