Accession Number:

AD0608061

Title:

Liquid Metal-Heated Space Radiator-Mounted Thermionic Generator,

Descriptive Note:

Rept. for 1 Jul 63-30 Jun 64,

Corporate Author:

PRATT AND WHITNEY AIRCRAFT EAST HARTFORD CONN

Personal Author(s):

Report Date:

1964-10-01

Pagination or Media Count:

158.0

Abstract:

The program was conducted to evaluate thermionic generators in a configuration appropriate for liquid metal heating at temperatures up to 1500C. The thermionic generator evaluated was cylindrical and consisted of a nickel collector surrounding a trilayer emitter structure. The trilayer structure consisted of a tantalum-tungsten alloy tube, which could contain the liquid metal, surrounded by a concentric insulating beryllium-oxide tube and a tungsten-rhenium alloy emitter tube. The generator met or exceeded the performance goals of the program. At an emitter temperature of 1500C, the power density measured was 50 percent greater than the design objective of 4 Wsquare cm, and the measured efficiency matched the goal of 10 per cent. The power density of 1.07 Wsquare cm at 1195C exceeded the performance goal of 1 Wsquare cm at 1200C. The generators were tested under conditions which simulated liquid metal heating and radiation cooling of the generators. Strong electronic and thermal interrelations were observed during these tests, significant discontinuities were found in the current-voltage relationship, and a thermal quasi-instability was observed resulting from variations in the electronic heating of the collector.

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE