Equations 1 through 9 were computerized, and conversion efficiencies and cesium plasma losses, Vj, determined for operational thermionic converters. The results for the pertinent range of emitter temperatures analyzed are shown in Figure 4-17. At the suggested 1800 K (2780°F) upper temperature limit for molybdenum, the power output is slightly above 8 W/cm2 (51.6 W/inch2). These computational methods were also applied to predicting future converter performance. Because of the high collector temperature required for effective radiative cooling in space, improvements in converter performance will not occur by reducing collector work functions, since performance degrading back electron emission would be -......... ' 't Fig. 4-17. Thermionic Diode Characteristics as a Function of Emitter Temperature for a Molybdenum Emitter and a Nickel (Molybdenum Coated) Collector Fig. 4-18. Increase in Efficiency and Output Voltage with Decreasing Plasma Drop for Constant I of 1290 A
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