Transient and Steady-State Analyses of an Electrically Heated Topaz-II Thermionic Fuel Element

Transient and steady-state analyses of electrically heated, Thermionic Fuel Elements (TFEs) for Topaz-II space power system were performed. The calculated emitter and collector temperatures, load electric power and conversion efficiency were in good agreement with reported data. The effects of Cs pressure, thermal power input, and load resistance on the steady-state performance of the TFE were also investigated. In addition, the thermal response of the ZrH moderator during a startup transient and following a change in the thermal power input was examined.