DocumentCode :
2331076
Title :
Characterization of the time-evolution of a microsecond electron beam diode with anode effects
Author :
Cuneo, M.E. ; Gilgenbach, Ronald M. ; Brake, Mary L. ; Enloe, C.L. ; Miller, Jason D. ; Repetti
Author_Institution :
Intense Energy Beam Interaction Lab., Michigan Univ., Ann Arbor, MI, USA
fYear :
1989
fDate :
0-0 1989
Firstpage :
101
Abstract :
Summary form only given, as follows. The time evolution of a low-aspect-ratio, microsecond-pulse-length, electron beam diode with anode plasmas, operating at initial current densities of approximately=100 A/cm/sup 2/, has been studied using a variety of experimental and empirical techniques. Of particular interest in this study was the observation of a transition to a roughly constant impedance regime. Very rapid cathode plasma closure velocities from 8-11 cm/s were observed. This expansion led to rapid self-filling of the diode, principally on-axis, causing dense plasma formation from the anode and resulting in the observed impedance characteristics. Due to the low-aspect-ratio diode design, many kiloamperes of electron current were still emitted, which interacted with the plasma that filled the diode from both the cathode and anode. Before self-filling, a low-effective-charge cathode plasma was observed, consisting almost exclusively of components derived from the hydrocarbon surface impurities. Evidence for cathode plasma instabilities was also noted. After self-filling, evidence for a beam-plasma interaction leading to RF emission, beam filamentation, and collective effects was suggested.<>
Keywords :
plasma diodes; plasma instability; plasma production; plasma-beam interactions; RF emission; anode effects; anode plasmas; beam filamentation; beam-plasma interaction; cathode plasma closure velocities; cathode plasma instabilities; collective effects; constant impedance regime; dense plasma formation; low-aspect-ratio diode design; low-effective-charge cathode plasma; microsecond electron beam diode; time-evolution; Diodes; Particle collisions; Plasma devices; Plasma generation; Plasma stability;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Plasma Science, 1989. IEEE Conference Record - Abstracts., 1989 IEEE International Conference on
Conference_Location :
Buffalo, NY, USA
Type :
conf
DOI :
10.1109/PLASMA.1989.166130
Filename :
166130
Link To Document :
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