Electron beam measurements for a laboratory simulation of auroral kilometric radiation

K. Ronald, S.L. McConville, David Speirs, A.D.R. Phelps, C.W. Robertson, C.G. Whyte, Wenlong He, Karen Gillespie, A.W. Cross, Robert Bingham

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Efficient (~1%) electron cyclotron radio emissions are produced in the X-mode from regions of locally depleted plasma in the Earth's polar magnetosphere. These emissions are commonly referred to as auroral kilometric radiation. Two populations of electrons exist with rotational kinetic energy to contribute to this effect, the downward propagating auroral electron flux which acquires transverse momentum due to conservation of the magnetic moment as it experiences an increasing magnetic field and the mirrored component of this flux. This paper demonstrates the production of an electron beam having a controlled velocity spread for use in an experiment to investigate the available free energy in the earthbound electron flux. The experiment was scaled to microwave frequencies and used an electron gun to inject an electron beam into a controlled region of increasing magnetic field produced by a set of solenoids reproducing the magnetospheric situation. Results are presented of the measurements of diode voltage, beam current as a function of magnetic mirror ratio and estimates of the line density versus electron pitch angle consistent with the formation of a horseshoe velocity distribution and demonstrating control of the electron distribution in velocity space.
Original languageEnglish
Number of pages8
JournalPlasma Sources Science and Technology
Volume17
Issue number3
DOIs
Publication statusPublished - Aug 2008
Event28th International Conference on Phenomena in Ionized Gases - Prague, Czech Republic
Duration: 15 Jul 200720 Jul 2007

Keywords

  • cyclotron maser instability
  • travelling-wave amplifier
  • gyroton experiments
  • field-emission
  • source region
  • plasmas
  • space
  • distributions

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