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

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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.

Fingerprint

electron flux
electron beams
magnetic mirrors
electron guns
pitch (inclination)
radiation
radio emission
solenoids
electron distribution
microwave frequencies
beam currents
magnetic fields
transverse momentum
magnetospheres
cyclotrons
conservation
electrons
simulation
velocity distribution
magnetic moments

Keywords

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

Cite this

@article{e24bac55d43e4ac1b9c93a47367512b9,
title = "Electron beam measurements for a laboratory simulation of auroral kilometric radiation",
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.",
keywords = "cyclotron maser instability , travelling-wave amplifier , gyroton experiments , field-emission , source region , plasmas , space , distributions",
author = "K. Ronald and S.L. McConville and David Speirs and A.D.R. Phelps and C.W. Robertson and C.G. Whyte and Wenlong He and Karen Gillespie and A.W. Cross and Robert Bingham",
year = "2008",
month = "8",
doi = "10.1088/0963-0252/17/3/035011",
language = "English",
volume = "17",
journal = "Plasma Sources Science and Technology",
issn = "0963-0252",
number = "3",

}

TY - JOUR

T1 - Electron beam measurements for a laboratory simulation of auroral kilometric radiation

AU - Ronald, K.

AU - McConville, S.L.

AU - Speirs, David

AU - Phelps, A.D.R.

AU - Robertson, C.W.

AU - Whyte, C.G.

AU - He, Wenlong

AU - Gillespie, Karen

AU - Cross, A.W.

AU - Bingham, Robert

PY - 2008/8

Y1 - 2008/8

N2 - 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.

AB - 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.

KW - cyclotron maser instability

KW - travelling-wave amplifier

KW - gyroton experiments

KW - field-emission

KW - source region

KW - plasmas

KW - space

KW - distributions

U2 - 10.1088/0963-0252/17/3/035011

DO - 10.1088/0963-0252/17/3/035011

M3 - Article

VL - 17

JO - Plasma Sources Science and Technology

T2 - Plasma Sources Science and Technology

JF - Plasma Sources Science and Technology

SN - 0963-0252

IS - 3

ER -