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Title: Cesium reservoir and interconnective components. Final test report: TFE Verification Program

Abstract

The program objective is to demonstrate the technology readiness of a TFE (thermionic fuel element) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW range. A thermionic converter must be supplied with cesium vapor for two reasons. Cesium atoms adsorbed on the surface of the emitter cause a reduction of the emitter work function to permit high current densities without excessive heating of the emitter. The second purpose of the cesium vapor is to provide space-charge neutralization in the emitter-collector gap so that the high current densities may flow across the gap unattenuated. The function of the cesium reservoir is to provide a source of cesium atoms, and to provide a reserve in the event that cesium is lost from the plasma by any mechanism. This can be done with a liquid cesium metal reservoir in which case it is heated to the desired temperature with auxiliary heaters. In a TFE, however, it is desirable to have the reservoir passively heated by the nuclear fuel. In this case, the reservoir must operate at a temperature intermediate between the emitter and the collector, ruling out the use of liquidmore » reservoirs. Integral reservoirs contained within the TFE will produce cesium vapor pressures in the desired range at typical electrode temperatures. The reservoir material that appears to be the best able to meet requirements is graphite. Cesium intercalates easily into graphite, and the cesium pressure is insensitive to loading for a given intercalation stage. The goals of the cesium reservoir test program were to verify the performance of Cs-graphite reservoirs in the temperature-pressure range of interest to TFE operation, and to test the operation of these reservoirs after exposure to a fast neutron fluence corresponding to seven year mission lifetime. In addition, other materials were evaluated for possible use in the integral reservoir.« less

Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10155363
Report Number(s):
GA-A-21595
ON: DE94012470; BR: 400403000/400403105; TRN: 94:012055
DOE Contract Number:  
AC03-86SF16298
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Mar 1994
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 30 DIRECT ENERGY CONVERSION; THERMIONIC FUEL ELEMENTS; WORKING FLUIDS; DESIGN; THERMIONIC REACTORS; PERFORMANCE TESTING; PROGRESS REPORT; TECHNOLOGY ASSESSMENT; THERMIONIC CONVERTERS; CESIUM; PERFORMANCE; FABRICATION; POST-IRRADIATION EXAMINATION; LIQUID METALS; EXPERIMENTAL DATA; NESDPS Office of Nuclear Energy Space and Defense Power Systems; 210600; 300403; 300402; POWER REACTORS, MOBILE, PROPULSION, PACKAGE, AND TRANSPORTABLE; MATERIALS, COMPONENTS, AND AUXILIARIES; PERFORMANCE AND TESTING

Citation Formats

Not Available. Cesium reservoir and interconnective components. Final test report: TFE Verification Program. United States: N. p., 1994. Web. doi:10.2172/10155363.
Not Available. Cesium reservoir and interconnective components. Final test report: TFE Verification Program. United States. doi:10.2172/10155363.
Not Available. Tue . "Cesium reservoir and interconnective components. Final test report: TFE Verification Program". United States. doi:10.2172/10155363. https://www.osti.gov/servlets/purl/10155363.
@article{osti_10155363,
title = {Cesium reservoir and interconnective components. Final test report: TFE Verification Program},
author = {Not Available},
abstractNote = {The program objective is to demonstrate the technology readiness of a TFE (thermionic fuel element) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW range. A thermionic converter must be supplied with cesium vapor for two reasons. Cesium atoms adsorbed on the surface of the emitter cause a reduction of the emitter work function to permit high current densities without excessive heating of the emitter. The second purpose of the cesium vapor is to provide space-charge neutralization in the emitter-collector gap so that the high current densities may flow across the gap unattenuated. The function of the cesium reservoir is to provide a source of cesium atoms, and to provide a reserve in the event that cesium is lost from the plasma by any mechanism. This can be done with a liquid cesium metal reservoir in which case it is heated to the desired temperature with auxiliary heaters. In a TFE, however, it is desirable to have the reservoir passively heated by the nuclear fuel. In this case, the reservoir must operate at a temperature intermediate between the emitter and the collector, ruling out the use of liquid reservoirs. Integral reservoirs contained within the TFE will produce cesium vapor pressures in the desired range at typical electrode temperatures. The reservoir material that appears to be the best able to meet requirements is graphite. Cesium intercalates easily into graphite, and the cesium pressure is insensitive to loading for a given intercalation stage. The goals of the cesium reservoir test program were to verify the performance of Cs-graphite reservoirs in the temperature-pressure range of interest to TFE operation, and to test the operation of these reservoirs after exposure to a fast neutron fluence corresponding to seven year mission lifetime. In addition, other materials were evaluated for possible use in the integral reservoir.},
doi = {10.2172/10155363},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1994},
month = {3}
}