The Emitter Envelopes for Power Intensive Thermionic Fuel Elements

Progress in development of thermionic fuel elements (TFE) of thermionic nuclear reactor-converters having more than 3 W/cm² specific electric capacity to the considerable extend is connected with the application of refractory crystal emitters on the base of tungsten and its alloys.

The technology of all single crystal (110) oriented tungsten emitter envelopes was developed at the IPPE. The sample lot of the envelopes was manufactured and then investigated during laboratory and lifetime electrically heated tests. One of the promising direction of this technology progress is the employment of tungsten facetted coating having mainly (110) orientation.

This report is development of [1,2,3]. In the report the investigation results of surface properties of emitter envelope facetted coating as well as results of lifetime tests of TEC with hexahedral geometry W(110) - W(110) electrode envelopes are discussed.