Analysis of ancillary equipment for solar- thermionic system, volume i final report
Solar concentrator thermionic converter, and generator for solar thermionic system
THERMIONIC CONVERTER↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Limits on Collisionless Model of Thermionic Converter
Limits on collisionless model of thermionic converter - volt-ampere characteristics for gaseous thermionic diodes
VOLT-AMPERE CHARACTERISTICS↗
Study shows effect of surface preparations on improving thermionic emission
Specimen thermionic emitters were electropolished and electroetched to study the effect of surface preparations on improving thermionic emission. The best technique found was to electropolish the annealed rhenium surface and then electroetch it. The effect of electroetching was to remove other crystal planes faster than basal planes.
Van ~someren, L.↗
Nuclear thermionic space power system concept employing heat pipes
Development of nuclear thermionic space power system using thermionic diodes, and heat pipe flow for temperature control
Heath, C. A.↗
Thermionic research and development program Final report, 15 Jul. 1966 - 15 Jan. 1968
Thermionic research and development program - improvement of performance of low emitter temperature cesium vapor thermionic converters
Campbell, A. E.↗
A reactor concept for space power employing thermionic diodes and heat pipes.
Thermionic generator power system using reactor heat source connected to external thermionic diodes by heat pipes, noting reactor control
Heath, C. A.↗
Thermionic converter and generator tests.
Thermionic generator and converters tested in Solar Energy Thermionic program
Rouklove, P.↗
Performance of low-pressure thermionic converters is evaluated
Experiments, evaluating the performance of low-pressure thermionic converters, were conducted with cesium, potassium, and sodium-metal vapors. The results of the investigation are useful in the selection of favorable conditions for the design of thermionic reactor fuel elements, including RF output for special applications.
Richards, H. K.↗
Thermionic triode generates ac power
Electrostatic grid controls conduction cycle of thermionic diode to convert low dc output voltages to high ac power without undesirable power loss. An ac voltage applied to the grid of this new thermionic triode enables it to convert heat directly into high voltage electrical power.
Kniazzeh, A. G. F.↗
Thermionic Diode Kinetics Experiment - Design and startup
Thermionic Diode Kinetics Experiment with on-line analog computer simulation, investigating thermionic reactor powerplant dynamics and control by nonnuclear means
Ernst, D.↗
A 5 kW/e/ radioisotope thermionic power supply for unmanned electric propulsion
Radioisotope thermionic power supply for unmanned electric propulsion missions to outer planets, using 69 modules consisting of thermionic converter and emitter heat pipe
Gietzen, A. J.↗
DEXTER: A one-dimensional code for calculating thermionic performance of long converters
A versatile code is described for computing the coupled thermionic electric-thermal performance of long thermionic converters in which the temperature and voltage variations cannot be neglected. The code is capable of accounting for a variety of external electrical connection schemes, coolant flow paths and converter failures by partial shorting. Example problem solutions are included along with a user's manual.
Sawyer, C. D.↗
Split-core heat-pipe reactors for out-of-pile thermionic power systems.
Description of the concept of splitting a heat-pipe reactor for out-of-core thermionics into two identical halves and using the resulting center gap for reactivity control. Short Li-W reactor heat pipes penetrate the axial reflectors and form a heat exchanger with long heat pipes which wind through the shield to the thermionic diodes. With one reactor half anchored to the shield, the other is attached to a long arm with a pivot behind the shield and swings through a small arc for reactivity control. A safety shim prevents large reactivity inputs, and a fueled control arm drive shaft acts as a power stabilizer. Reactors fueled with U-235C and with U-233C have been studied.-
Niederauer, G.↗
External fuel thermionic reactor system.
Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.
Mondt, J. F.↗
Detailed design of a 100-We multicell thermionic power supply.
Confirmation of the general trends of a previously reported parametric study of plutonia-fueled thermionic generators in a detailed 100-We generator design. The detailed design takes into account the additional weight of system-integration components and shows that design refinements of all aeroshell components are possible when a specific generator configuration is considered. An optimized 100-We thermionic power supply design is presented, reflecting a 0.98 reliability goal after five years of operation. The optimum multicell array consists of 28 isomite converters, each producing approximately 3.6 We at end-of-life. The optimum arrangement of converters in the aeroshell is a four-column, seven-row stacking configuration connected electrically as a two-column, 14-row array.
Rouklove, P.↗
Design of an external-fueled thermionic diode for in-pile testing.
Description of an external-fueled thermionic diode suitable for in-pile testing in a research reactor. The active electrode area is 94 sq cm. The 10-in. long, 1.5-in.-OD emitter body is tungsten 2% thoria. The fuel is contained in six 0.4-in.-diam holes equally spaced about the 0.5-in. central emitter hole. The collector is niobium-1% zirconium. The expected diode performance is 6 W/sq cm at 2000 K. In addition to following the constraints imposed by the in-pile testing and the electrically heated performance mapping prior to insertion in-pile, the diode will have end configurations prototypical of those anticipated for a flow-through, NaK-cooled, external-fuel thermionic reactor.
Ernst, D. M.↗
Dexter - A one-dimensional code for calculating thermionic performance of long converters.
This paper describes a versatile code for computing the coupled thermionic electric-thermal performance of long thermionic converters in which the temperature and voltage variations cannot be neglected. The code is capable of accounting for a variety of external electrical connection schemes, coolant flow paths and converter failures by partial shorting. Example problem solutions are given.
Sawyer, C. D.↗
Sizing an external-fueled in-core thermionic reactor.
Parametric studies on sizing of external-fueled in-core thermionic reactors are presented. Reactor physics results obtained for a variety of fuel element designs are used as a basis for nuclear criticality, power distribution, and control worth design. Thermionic performance results for a single fuel element for several sets of operating conditions are presented. An algorithm combining the electrical and reactor physics results in a form amenable to preliminary systems analysis is presented.
Nakashima, A. M.↗