Time-Dependent Plasma Behavior Triggered by a Pulsed Electron Gun under Conditions of Beam-Plasma-Discharge

  • Edward P. Szuszczewicz
  • C. S. Lin
Part of the NATO Advanced Study Institutes Series book series (NSSB, volume 79)


We have conducted a number of experiments intended to simulate spaceborne applications of energetic electron guns while exploring the “in situ” diagnostics of time-dependent beam-plasma behavior under pulsed electron gun conditions. The conditions include the beam-plasma-discharge (BPD) and the BPD afterglow that exists after gun-pulse termination. With electron gun characteristics set at (Ig, Vg, Ton /Toff) = (34 ma, 1.9 keV, 80 ms/270 ms) and a superimposed magnetic field at 1.5 gauss, the results show that: (i) There is a three order-of-magnitude increase in plasma density within 5 ms of gun turn-on; (ii) During the pulse-ON time a quasi-steady-state BPD is maintained with characteristics identical to dc-BPD conditions; (iii) Plasma losses appear to be dominated by Bohm-like diffusion processes; and finally (iv) The afterglow can be characterized by an isodensity radial profile that decays with a 36 msec time constant and cools at a 3.8(103) °K/sec rate.


Radial Diffusion Langmuir Probe Electron Density Profile Beam Plasma Plasma Loss 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Anderson, H., Bernstein, W., Papadopoulos, K., Szuszczewicz, E.P., and Linson, L.M., 1979, “A Theoretical and Experimental Investigation of Beam-Plasma Physics”, Proposal submitted to NASA.Google Scholar
  2. Bernstein, W., Leinbach, H., Kellog, P., Monson, S., Hallinan, T., Garriott, O. K., Konradi, A., McCoy, J., Daly, P., Baker, B., and Anderson, H.R., 1978, “Electron Beam Injection Experiments: The Beam-Plasma Discharge at Low Pressures and Magnetic Field Strengths”, Geophys. Res. Lett. 5:127.ADSCrossRefGoogle Scholar
  3. Bernstein, W., Whalen, B.A., Harris, F.R., McNamara A.G., and Konradi, A., 1980, “Laboratory Studies of the Charge Neutralization of a Rocket Payload During Electron Beam Emission”, Geophys. Res. Lett. 7:93.ADSCrossRefGoogle Scholar
  4. Chen, F.F., 1965, Chapter 4, in “Plasma Diagnostics Techniques”, R.H. Huddlestone and S.L. Leonard, ed., Academic, New York.Google Scholar
  5. Holmes, J.C. and Szuszczewicz, E.P., 1975, “A Versatile Plasma Probe” Rev. Sci. Instr. 46:592.ADSCrossRefGoogle Scholar
  6. Holmes, J.C. and Szuszczewicz, E.P., 1981, “A Plasma Probe System with Automatic Sweep Adjustment”, Rev. Sci. Instr. Google Scholar
  7. Jost, R.J., Anderson, H.R. and McGarity, J.O., 1981, “Measured Electron Energy Distributions During Electron Beam-Plasma Interactions”, Geophys. Res. Lett. 7:509.ADSCrossRefGoogle Scholar
  8. Linson, L.M. and Papadopoulos, K., 1980, “Review of the Status of Theory and Experiment for Injection of Energetic Beams in Space”, Report No. LAPS 69 SAI-023–80–459-LJ, Science Applications Inc., La Jolla, CA.Google Scholar
  9. Papadopoulos, K., 1981, Private Communication.Google Scholar
  10. Rowland, H.L., Chang, C.L., and Papadopoulos, K., 1981 (in press), “Sealing of the beam plasma discharge”, J. Geophys. Res. Google Scholar
  11. Szuszczewicz, E.P. and Holmes, J.C., 1977, “Observations of Electron Temperature Gradients in Mid-Latitude ES-Layers”, J. Geophys. Res. 82:5073.ADSCrossRefGoogle Scholar
  12. Szuszczewicz, E.P., 1979, “Plasma Diffusion in a Space-Simulation Beam-Plasma-Discharge”, Geophys Res. Lett. 6:201.ADSCrossRefGoogle Scholar
  13. Takacs, P.Z. and Szuszczewicz, E.P., 1979, “Magnetosheath Effects on Cylindrical Langmuir Probes”, Phys. Fluids, 22:2424.Google Scholar
  14. Walker, D.N., Lin, C.S., and Szuszczewicz, E.P., 1981, “Ignition of the Beam-Plasma-Discharge and It’s Dependence on Electron Density”, in Beam Experiments in Space, Bjorn Grandal, Ed., Plenum Publishing Corp., New York, NY.Google Scholar

Copyright information

© Plenum Press, New York 1982

Authors and Affiliations

  • Edward P. Szuszczewicz
    • 1
  • C. S. Lin
    • 2
  1. 1.Naval Research LaboratoryE. O. Hulbert Center for Space ResearchUSA
  2. 2.Bendix Field Engineering Corp.ColumbiaUSA

Personalised recommendations