Thermoemission reactor-converters for nuclear power units in outer space

Gryaznov, G. M.; Zhabotinskii, E. E.; Zrodnikov, A. V.; Nikolaev, Yu.V.; Ponomarev-Stepnoi, N. N.; Pupko, V. Ya.; Serbin, V. I.; Usov, V. A.

doi:10.1007/bf01123508

Cited by 13 publications

(4 citation statements)

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“…Solar concentrators may be used in conjunction with vacuum tube-based thermionic conversion to generate electrical energy. 77 Thermionic conversion requires vacuum tube materials – fused silica glass, tungsten, nickel, Kovar and calcium oxide which can be sourced on the Moon – a calcium oxide coated tungsten cathode may be sourced from anorthite minerals and nickel–iron meteorites; a nickel control grid and anode may be sourced from nickel–iron meteorites; Kovar wiring may be sourced from nickel–iron meteorites; and a fused silica glass tube may be sourced from silicate minerals. Vacuum tube-based technology has the advantage of being highly radiation-tolerant unlike solid state devices.…”

Section: Introductionmentioning

confidence: 99%

Generating and storing power on the moon using in situ resources

Ellery

2021

Proceedings of the Institution of Mechanical Engineers, Part G:

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The Moon Village and similar concepts are strongly reliant on in situ resource utilisation (ISRU). There is great interest in harvesting solar power using locally leveraged in situ resources as an essential facet of in situ infrastructure. Traditionally, silicon-based photovoltaic cells have been assumed, preferably manufactured in situ using a 3D printing rover, but there are major difficulties with such scenarios. Solar cells require pre-processing of regolith and solar cell manufacture. We present an alternative lunar resource leveraged-solar power production system on the Moon which can yield high conversion efficiencies – solar Fresnel lens-thermionic conversion. The thermionic vacuum tube is constructed from lunar-derived materials and NiFe asteroidal ores on the Moon. Given that the majority of energy required for ISRU is thermal, thermionic conversion exploits this energy source directly. Silicates such as anorthite can be treated with acid to yield alumina and silicic acid in solution from which pure silica can be precipitated. Pure silica when heated to high temperature yields fused silica glass which is transparent – fused silica glass may be employed to manufacture Fresnel lenses and/or mirrors. Both silica and alumina may be input to the Metalysis Fray Farthing Chen Cambridge electrolytic process to yield near pure Si and near pure Al, respectively.

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Section: Introductionmentioning

confidence: 99%

Generating and storing power on the moon using in situ resources

Ellery

2021

Proceedings of the Institution of Mechanical Engineers, Part G:

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“…Thermionic emission (TE) occurs when certain metals or semiconductors are heated beyond an emission threshold temperature, and thermally excited electrons have enough energy to overcome the surface potential barrier, leaving the solid with an associated kinetic energy. , TE has played a vital role in the technological development of electronic devices since the early 20th century owing to its use in vacuum valves for current rectification employed in radars and analog computers. TE was later used in the development of X-ray sources, pressure gauges, and thermionic energy converters for space applications. , The development of TE-based technologies was very intense up until the 1980s but then declined until the development of new materials with novel electronic properties prompted a revival of the research in this field. Among these materials were carbon nanotubes and hydrogen-terminated diamond, which could emit thermionic electrons at significantly lower temperatures , than traditional thermionic materials (e.g., molybdenum with T emission >1700 K) and therefore became candidates to be low-temperature electron emitters that would be more energetically efficient than traditional alternatives.…”

Section: Introductionmentioning

confidence: 99%

“…TE was later used in the development of X-ray sources, 4 pressure gauges, and thermionic energy converters for space applications. 5,6 The development of TE-based technologies was very intense up until the 1980s but then declined until the development of new materials with novel electronic properties prompted a revival of the research in this field. Among these materials were carbon nanotubes 7 and hydrogen-terminated diamond, which could emit thermionic electrons at significantly lower temperatures 8,9 than traditional thermionic materials (e.g., molybdenum with T emission >1700 K) 10 and therefore became candidates to be low-temperature electron emitters that would be more energetically efficient than traditional alternatives.…”

Section: ■ Introductionmentioning

confidence: 99%

Correlating Thermionic Emission with Specific Surface Reconstructions in a <100> Hydrogenated Single-Crystal Diamond

Andrade

Anaya

Croot

et al. 2020

ACS Appl. Mater. Interfaces

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Thermionic emission relies on the low work function and negative electron affinity of the, often functionalized, surface of the emitting material. However, there is little understanding of the interplay between thermionic emission and temperature-driven dynamic surface transformation processes as these are not represented on the traditional Richardson–Dushman equation for thermionic emission. Here, we show a new model for thermionic emission that can reproduce the effect of dynamic surface changes on the electron emission and correlate the components of the thermionic emission with specific surface reconstruction phases on the surface of the emitter. We use hydrogenated <100> single-crystal and polycrystalline diamonds as thermionic emitters to validate our model, which shows excellent agreement with the experimental data and could be applicable to other emitting materials. Furthermore, we find that tailoring the coverage of specific structures of the C(100)-(2 × 1):H surface reconstruction could increase the thermionic emission of diamond by several orders of magnitude.

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“…Another potential application of thermionic emission is in thermionic energy converters (TECs), which can produce a direct conversion of heat into electrical power using no moving parts (Gryaznov et al, 1989;Mills and Dahlberg, 1991).…”

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confidence: 99%

Beta Radiation Enhanced Thermionic Emission from Diamond Thin Films

et al. 2017

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Diamond-based thermionic emission devices could provide a means to produce clean and renewable energy through direct heat-to-electrical energy conversion. Hindering progress of the technology are the thermionic output current and threshold temperature of the emitter cathode. In this report, we study the effects on thermionic emission caused by in situ exposure of the diamond cathode to beta radiation. Nitrogen-doped diamond thin films were grown by microwave plasma chemical vapor deposition on molybdenum substrates. The hydrogen-terminated nanocrystalline diamond was studied using a vacuum diode setup with a 63 Ni beta radiation source-embedded anode, which produced a 2.7-fold increase in emission current compared to a 59 Ni-embedded control. The emission threshold temperature was also examined to further assess the enhancement of thermionic emission, with 63 Ni lowering the threshold temperature by an average of 58 ± 11 °C compared to the 59 Ni control. Various mechanisms for the enhancement are discussed, with a satisfactory explanation remaining elusive. Nevertheless, one possibility is discussed involving excitation of preexisting conduction band electrons that may skew their energy distribution toward higher energies.

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Thermoemission reactor-converters for nuclear power units in outer space

Cited by 13 publications

References 0 publications

Generating and storing power on the moon using in situ resources

Generating and storing power on the moon using in situ resources

Correlating Thermionic Emission with Specific Surface Reconstructions in a <100> Hydrogenated Single-Crystal Diamond

Beta Radiation Enhanced Thermionic Emission from Diamond Thin Films

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