Ion Thruster Operation with Carbon Nanotube Field Emission Cathode

Yamamoto, Naoji; Morita, T.; Ohkawa, Yasushi; Nakano, Masahiro; Funaki, Ikkoh

doi:10.2514/1.b37214

Cited by 13 publications

(11 citation statements)

References 24 publications

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“…The cathode is constructed with a gate grid electrode and a mask grid electrode, in order to apply a strong electric field to the carbon nanotube. 18) The open area is rectangular, 3 Â 0:28 mm 2 and the open area ratio is about 80%. Both electrodes are made of thin molybdenum plate.…”

Section: Field Emission Cathode With Carbon Nanotubesmentioning

confidence: 99%

“…Conventional ion engines provide about 20-25% of their propellant to the cathodes, [9][10][11][12] and this leads to 20-25% degradation of the specific impulse. In our previous work, the neutralization of an ion engine using xenon gas as a propellant with a field emission neutralizer was successfully demonstrated, 2) though the electron emission cost was 360 W/A, which is higher than that of a conventional hollow cathode (less than 30 W/A). 13) Small hollow cathodes, whose emission current is in the range of 10-100 mA, consume several watts, which means that the electron emission cost of a small hollow cathode is more than 250 W/A.…”

Section: Introductionmentioning

confidence: 99%

“…For small satellite applications, 2) power consumption is an important factor. A field emission cathode (FEC) [3][4][5][6] is therefore an attractive candidate for the electron source, since it has lower power consumption than conventional cathodes (such as hollow cathodes, microwave discharge cathodes, or radio-frequency discharge cathodes) and it does not consume propellant.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Position and Attitude Tolerances of Carbon Nanotube Field Emission Cathode as a Neutralizer in an Ion Engine System

Kinoshita

Ikeda

Adachi

et al. 2021

Trans. Japan Soc. Aero. S Sci.

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Section: Field Emission Cathode With Carbon Nanotubesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Position and Attitude Tolerances of Carbon Nanotube Field Emission Cathode as a Neutralizer in an Ion Engine System

Kinoshita

Ikeda

Adachi

et al. 2021

Trans. Japan Soc. Aero. S Sci.

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“…Recently, in 2019, Yamamoto et al [43] have further investigated the demonstration of the CNT‐FEC as neutraliser for microwave ion thruster. The schematic and setup of CNT‐FEC is shown in Fig.…”

Section: Recent Progresses Of Cnt‐fec Applications On Space Propulsmentioning

confidence: 99%

“…Schematic and setup of CNT-FEC used for a microwave ion thruster in Japan. The figure is reproduced from[43] (a) Schematic, (b) Setup Fig. 11 Schematic view of lab-model of CNT-FECs in JAXA.…”

mentioning

confidence: 99%

Review on development of carbon nanotube field emission cathode for space propulsion systems

2020

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In recent years, small‐size, low‐weight aerospace propulsion systems have developed rapidly for space exploration, on‐orbit scientific instruments and extra space missions, while additional electron emission devices are commonly required in those propulsion systems. Carbon nanotube (CNT) based field emission cathodes exhibit extraordinary field emission properties and are regarded to be an ideal alternative of conventional thermionic or hollow cathodes. In this study, the authors give an overview of present status of researches on CNT‐based electron emission cathodes for utilising as neutralisers or electron sources particularly in space electric propulsion systems, the theory and characteristics of CNT are also illustrated. Furthermore, challenges, problems and possible solutions before actual applications of CNT in a space mission are discussed accordingly.

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Integration of Vertical Graphene Onto a Tunnelling Cathode for Digital X‐Ray Imaging

Jerng,

Hong,

Lee

et al. 2024

Advanced Science

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As an alternative to thermionic X‐ray generators, cold‐cathode X‐ray tubes are being developed for portable and multichannel tomography. Field emission propagating from needle structures such as carbon nanotubes or Si tips currently dominates related research and development, but various obstacles prevent the widespread of this technology. An old but simple electron emission design is the planar tunnelling cathode using a metal–oxide–semiconductor (MOS) structure, which achieves narrow beam dispersion and low supplying voltage. Directly grown vertical graphene (VG) is employed as the gate electrode of MOS and tests its potential as a new emission source. The emission efficiency of the device is initially ≈1% because of unavoidable fabrication damage during the patterning processes; it drastically improves to >40% after ozone treatment. The resulting emission current obeys the Fowler–Nordheim tunnelling model, and the enhanced emission is attributed to the effective gate thickness reduction by ozone treatment. As a proof‐of‐concept experiment, a clustered array of 2140 cells is integrated into a system that provides mA‐class emission current for X‐ray generation. With pulsed digital excitations, X‐ray imaging of a chest phantom, demonstrating the feasibility of using a VG MOS electron emission source as a new and innovative X‐ray generator is realized.

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Ion Thruster Operation with Carbon Nanotube Field Emission Cathode

Cited by 13 publications

References 24 publications

Position and Attitude Tolerances of Carbon Nanotube Field Emission Cathode as a Neutralizer in an Ion Engine System

Position and Attitude Tolerances of Carbon Nanotube Field Emission Cathode as a Neutralizer in an Ion Engine System

Review on development of carbon nanotube field emission cathode for space propulsion systems

Integration of Vertical Graphene Onto a Tunnelling Cathode for Digital X‐Ray Imaging

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