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

Journal Article · Fri Jan 10 04:00:00 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, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 387; ISSN 0094-243X; ISSN APCPCS
• 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
NESDPS Office of Nuclear Energy Space and Defense Power Systems
OPTIMIZATION
SPACE VEHICLES
STEADY-STATE CONDITIONS
THERMIONIC CONVERSION
THERMIONIC CONVERTERS
THERMIONIC FUEL ELEMENTS
THERMIONIC REACTORS
TOPAZ REACTOR
WORK FUNCTIONS