Diminiode thermionic conversion with 111-iridium electrodes

Technical Report · Wed Sep 01 04:00:00 EDT 1976

OSTI ID:7212401

Koeger, E W; Bair, V L; Morris, J F

Preliminary data indicating thermionic-conversion potentialities for a 111-iridium emitter and collector spaced 0.2 mm apart are presented. These results comprise output densities of current and of power as functions of voltage for three sets of emitter, collector, and reservoir temperatures: 1553, 944, 561 K; 1605, 898, 533 K; and 1656, 1028, 586 K. For the 1605 K evaluation, estimates produced work-function values of 2.22 eV for the emitter and 1.63 eV for the collector with a 2.0-eV barrier index (collector work function plus interelectrode voltage drop) corresponding to the maximum output of 5.5 W/sq cm at 0.24 volt. The current, voltage curve for the 1656 K 111-iridium diminiode yields a 6.2 W/sq cm maximum at 0.25 volt and is comparable with the 1700 K envelope for a diode with an etched-rhenium emitter and a 0.025-mm electrode gap made by TECO and evaluated by NASA.

• Research Organization: National Aeronautics and Space Administration, Cleveland, Ohio (USA). Lewis Research Center
• OSTI ID: 7212401
• Report Number(s): N-76-33991; NASA-TM-X-73492; E-8888
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300402* -- Thermionic Converters-- Performance & Testing
DIODE TUBES
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELECTRON TUBES
ELEMENTS
IRIDIUM
METALS
NESDPS Office of Nuclear Energy Space and Defense Power Systems
PERFORMANCE
PHYSICAL PROPERTIES
PLATINUM METALS
REFRACTORY METALS
THERMIONIC COLLECTORS
THERMIONIC CONVERTERS
THERMIONIC DIODES
THERMIONIC EMITTERS
THERMIONIC TUBES
TRANSITION ELEMENTS
VOLTAGE DROP
WORK FUNCTIONS