Comparison between steady-state and dynamic I-V measurements from a single-cell thermionic fuel element

Journal Article · Fri Jan 10 00:00:00 EST 1997 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.51979· OSTI ID:21165723

Wernsman, Bernard ^[1]

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1. New Mexico Engineering Research Institute Thermionics Evaluation Facility 901 University SE Albuquerque, New Mexico 87106 (United States)

A comparison between steady-state and dynamic I-V measurements from a single-cell thermionic fuel element (TFE) is made. The single-cell TFE used in this study is the prototype for the 40 kW{sub e} space nuclear power system that is similar to the 6 kW{sub e} TOPAZ-II. The steady-state I-V measurements influence the emitter temperature due to electron cooling. Therefore, to eliminate the steady-state I-V measurement influence on the TFE and provide a better understanding of the behavior of the thermionic energy converter and TFE characteristics, dynamic I-V measurements are made. The dynamic I-V measurements are made at various input power levels, cesium pressures, collector temperatures, and steady-state current levels. From these measurements, it is shown that the dynamic I-V's do not change the TFE characteristics at a given operating point. Also, the evaluation of the collector work function from the dynamic I-V measurements shows that the collector optimization is not due to a minimum in the collector work function but due to an emission optimization. Since the dynamic I-V measurements do not influence the TFE characteristics, it is believed that these measurements can be done at a system level to understand the influence of TFE placement in the reactor as a function of the core thermal distribution.

• OSTI ID: 21165723
• Journal Information: AIP Conference Proceedings, Vol. 387, Issue 1; Conference: STAIF-97: Space technology and applications international forum, Albuquerque, NM (United States), 26-30 Jan 1997; Other Information: DOI: 10.1063/1.51979; (c) 1997 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
30 DIRECT ENERGY CONVERSION
CESIUM
COMPARATIVE EVALUATIONS
ELECTRIC CONDUCTIVITY
ELECTRON COOLING
OPTIMIZATION
SPACE VEHICLES
STEADY-STATE CONDITIONS
THERMIONIC CONVERSION
THERMIONIC CONVERTERS
THERMIONIC FUEL ELEMENTS
THERMIONIC REACTORS
TOPAZ REACTOR
WORK FUNCTIONS
NESDPS Office of Nuclear Energy Space and Defense Power Systems