Electric strength of metal-ceramic brazed units of thermionic energy converters in caesium vapours

• Published in: Proceedings of the 24th Intersociety Energy Conversion Engineering Conference pp. 2743 - 2748 vol.6
• Main Authors: Belousenko, A.P., Vasilchenko, A.V., Nikolaev, Y.V.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1989
• Subjects: Aluminum oxide; Ceramics; Dielectrics and electrical insulation; Electric resistance; Electric variables measurement; Equations; Length measurement; Pressure measurement; Surface resistance; Temperature dependence
• DOI: 10.1109/IECEC.1989.74380

The electric strength characteristics of the hollow metal-ceramic brazed units of thermionic energy converters have been investigated. The insulators was polycrystalline aluminum oxide of length l=10-50 mm, and measurements were made at temperature T=450-750 degrees C and the caesium vapor pressure P/sub Cs/=10/sup -1/-10/sup 3/ Pa. The experimental dependences of the breakdown voltage of the brazed units on the temperature, the parameter P/sub Cs/*l, and the value of the surface electric resistance of the insulators are given as well as the empirical equations obtained from the experimental data for calculating the breakdown voltage. A mechanism explaining the influence of the ceramic insulator on the electric strength characteristics of the caesium gap has been investigated. A breakdown model that includes this influence is proposed.< >