Evidence of fireball phenomena in hollow cathode of electron bombardment ion thrusters.

AIAA Journal ◽  
1973 ◽  
Vol 11 (3) ◽  
pp. 399-400
Author(s):  
R. A. JACOBSEN ◽  
H. P. EUBANK
Keyword(s):  
Hollow Cathode ◽  
Electron Bombardment ◽  
Ion Thrusters

scholarly journals Hollow Cathode and Low-Thrust Extraction Grid Analysis for a Miniature Ion Thruster

2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
Richard Wirz ◽  
Regina Sullivan ◽  
JoHanna Przybylowski ◽  
Mike Silva
Keyword(s):  
Hollow Cathode ◽  
High Efficiency ◽  
Low Thrust ◽  
Discharge Performance ◽  
Ion Thruster ◽  
Ion Extraction ◽  
Ion Thrusters ◽  
Future Space ◽  
Thrust Characteristics ◽  
Computational Analyses

Miniature ion thrusters are well suited for future space missions that require high efficiency, precision thrust, and low contamination in the mN to sub-mN range. JPL's miniature xenon Ion (MiXI) thruster has demonstrated an efficient discharge and ion extraction grid assembly using filament cathodes and the internal conduction (IC) cathode. JPL is currently preparing to incorporate a miniature hollow cathode for the MiXI discharge. Computational analyses anticipate that an axially upstream hollow cathode location provides the most favorable performance and beam profile; however, the hot surfaces of the hollow cathode must be sufficiently downstream to avoid demagnetization of the cathode magnet at the back of the chamber, which can significantly reduce discharge performance. MiXI's ion extraction grids are designed to provide >3 mN of thrust; however, previous to this effort, the low-thrust characteristics had not been investigated. Experimental results obtained with the MiXI-II thruster (a near replica or the original MiXI thruster) show that sparse average discharge plasma densities of ∼5×1015–5×1016 m-3 allow the use of very low beamlet focusing extraction voltages of only ∼250–500 V, thus providing thrust levels as low as 0.03 mN for focused beamlet conditions. Consequently, the thrust range thus far demonstrated by MiXI in this and other tests is 0.03–1.54 mN.

Wear Test of a Hollow Cathode for 35-cm Xenon Ion Thrusters

2002 ◽  
Author(s):  
Yukio Hayakawa ◽  
Shoji Kitamura ◽  
Katsuhiro Miyazaki ◽  
Hideki Yoshida ◽  
Kouseki Akai ◽  
...  
Keyword(s):  
Hollow Cathode ◽  
Wear Test ◽  
Ion Thrusters

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

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