TEC and ultralloys for high-power space systems

Increasing space nuclear reactor (SNR) power requirements force system weights and temperatures upward. For such growth, thermionic energy conversion (TEC) excels in SNR service between tenths of a megawatt and about ten megawatts. TEC yields much current at low voltage, and, as total outputs soar, radiators at 400 K for conventional power conditioning (PC) balloon, compared with those at 1000 K and higher for TEC itself. To reduce PC problems, TEC requires contiguous high-temperature inversion or internal electromagnetic wave generation. Both are possible, potentially practical, and probably exploitable through research. However, attaining suitable efficiencies with these different operating modes and higher rejection temperatures demands new electrode and additive technologies, as well as decreased cesium pressures and increased TEC temperatures. Furthermore, such thermal growth necessitates alloys that approach ultimate metal capabilities for space applications. 19 references