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Diamond Thin Film Exposure to Simulated Thermionic Reactor Environments
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English
Abstract
The high temperature and high neutron flux environment of a thermionic space power reactor presents a challenge in the design of the sheath insulator within a thermionic fuel element. The present alumina insulator design is suspect to degradation due to the neutron flux. The alumina insulator also requires a barrier coating to isolate it from the liquid alkali metal coolant. Although the alumina sheath development is progressing, the alumina insulator remains a potential point of significant performance loss in the thermionic fuel element.
The recent successes in depositing polycrystalline diamond film onto cylindrical refractory metal substrates has led to the consideration of diamond as a potentially ideal sheath insulator. Investigations have been conducted into the durability of diamond thin film under exposure to simulated thermionic reactor conditions. Results will be presented from exposure tests in which diamond film has been subjected to a continuous flow of sodium coolant at 1000K and in which a cylindrical fuel element size diamond film has been exposed to simulated reactor temperatures and analyzed through microscopy. This paper relates these results to the development status of the diamond film thermionic sheath insulator.
Authors
Citation
Adams, S., Clausing, R., Tagavi, K., and John Hahn, O., "Diamond Thin Film Exposure to Simulated Thermionic Reactor Environments," SAE Technical Paper 929303, 1992, https://doi.org/10.4271/929303.Also In
References
- Adams S.F. Landstrass M.I. “CVD Diamond Coated Cylinders for Advanced Thermionic Fuel Element” Applications of Diamond Films and Related Materials Elsevier New York 1991
- Lamp T.R. Donovan B.D. “The Advanced Thermionics Initiative Program” Proceeding of the 26th IECEC 3 132 August 1991
- Clausing R.E. Heatherly L. “Examination of Diamond Coated Molybdenum Tubes for Thermionic Application” Interagency Agreement #1418-DO74-A1 & USAFSTC 90-91 1991
- Wang Z.L. Bentley J. Clausing R.E. Heatherly L. Horton L.L “Growth Mechanisms of CVD Diamond Films Determined by Novel TEM Technique” Applications of Diamond Films and Related Materials Elsevier New York 1991
- Landstrass M.I. Plano M.A. Moyer D. “Diamond Coatings for Improved Thermionic Power Systems” Air Force Contract No. F33615-90-C-2056 1991
- Lake M.L. Hickok J.K. Lide A.M. “Diamond Thin Films for TFE Sheath Insulators” Air Force Contract No. F33615-89-C-2960 1990
- Tsao B.H. Ramalingam M.L. Adams S.F. Cloyd J.S. “Adherence of Diamond Films on Refractory Metal Substrates for Thermionic Applications” 26th IECEC August 1991