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Fosnight, V. V.

Publications and source records attributed to Fosnight, V. V..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

High frequency plasma generator for ion thrusters

The results of a program to experimentally develop two new types of plasma generators for 30 cm electrostatic argon ion thrusters are presented. The two plasma generating methods selected for this study were by radio frequency induction (RFI), operating at an input power frequency of 1 MHz, and by electron cyclotron heating (ECH) at an operating frequency of 5.0 GHz. Both of these generators utilize multiline cusp permanent magnet configurations for plasma confinement and beam profile optimization. The program goals were to develop a plasma generator possessing the characteristics of high electrical efficiency (low eV/ion) and simplicity of operation while maintaining the reliability and durability of the conventional hollow cathode plasma sources. The RFI plasma generator has achieved minimum discharge losses of 120 eV/ion while the ECH generator has obtained 145 eV/ion, assuming a 90% ion optical transparency of the electrostatic acceleration system. Details of experimental tests with a variety of magnet configurations are presented.

Goede, H.↗
NASA NTRS1981

High Frequency Plasma Generators for Ion Thrusters

The results of a one year program to experimentally adapt two new types of high frequency plasma generators to Argon ion thrusters and to analytically study a third high frequency source concept are presented. Conventional 30 cm two grid ion extraction was utilized or proposed for all three sources. The two plasma generating methods selected for experimental study were a radio frequency induction (RFI) source, operating at about 1 MHz, and an electron cyclotron heated (ECH) plasma source operating at about 5 GHz. Both sources utilize multi-linecusp permanent magnet configurations for plasma confinement. The plasma characteristics, plasma loading of the rf antenna, and the rf frequency dependence of source efficiency and antenna circuit efficiency are described for the RFI Multi-cusp source. In a series of tests of this source at Lewis Research Center, minimum discharge losses of 220+/-10 eV/ion were obtained with propellant utilization of .45 at a beam current of 3 amperes. Possible improvement modifications are discussed.

Divergilio, W. F.↗
NASA NTRS1981

Ion propulsion for shared Shuttle, sun-synchronous missions

The configuration of an ion propulsion module (IPM) for use in the deployment and retrieval of sun-synchronous satellites on shared Shuttle flights is described. In addition to enabling shared Shuttle payloads requiring large orbital plane changes for achieving desired viewing conditions, the IPM makes over 10 kw available for payload power-sharing on orbit. The IPM also affords a large on-orbit propulsion capability. It has 2.8 x 10 to the 7th N-sec available at full propellant loading, of which less than half was needed for deploying and retrieving the representative spacecraft studied. Its remaining propulsion capability can be used for increasing payload or for additional propulsive functions on orbit.

Zafran, S.↗