Waves generated by pulsed electron beams

Torsten Neubert; K.J. Harker; P.M. Banks; E.G.D. Reeves; D.A. Gurnett

doi:10.1016/0273-1177(90)90287-A

Waves generated by pulsed electron beams

Torsten Neubert, K.J. Harker, P.M. Banks, E.G.D. Reeves, D.A. Gurnett

Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review

Abstract

During the Spacelab-2 flight of July, 1985, electron beams (1 keV, 100 mA) square-wave modulated at ELF and VLF were emitted from the space shuttle. The wave fields generated by the beam were monitored by a free-flying sub-satellite at distances up to 300 m perpendicular to the beam. The amplitude of the magnetic and electric fields were modulated by the spin of the satellite. This modulation allows the study of the wave polarization. Results for a 7 min duration beam sequence in which the beam was pulsed at 1.22 kHz are presented and compared with recent predictions for wave-fields stimulated by ideal helical electron beams propagating in a magnetized plasma. It is found that the predicted magnetic field amplitude of the first harmonic of the beam pulsing frequency (below the lower hybrid frequency) is in agreement with observations, however, the predicted and the observed polarizations are entirely different. For the higher harmonic components (above the lower hybrid frequency), theory predicts order of magnitude larger magnetic field amplitudes than observed. It is concluded that the theory does not adequately model the full distribution of the radiating current.

Original language	English
Title of host publication	Active Experiments/Critical Ionization Velocity
Publisher	Pergamon Press
Publication date	1990
Pages	137-142
ISBN (Print)	0-08-040164-3
DOIs	https://doi.org/10.1016/0273-1177(90)90287-A
Publication status	Published - 1990
Externally published	Yes
Event	Workshop of the Topical Meeting of the Interdisciplinary Commission of the COSPAR 27th Plenary Meeting: Active Experiments/Critical Ionization Velocity - Espoo, Finland Duration: 18 Jul 1988 → 29 Jul 1988 Conference number: 27

Workshop

Workshop	Workshop of the Topical Meeting of the Interdisciplinary Commission of the COSPAR 27th Plenary Meeting
Number	27
Country/Territory	Finland
City	Espoo
Period	18/07/1988 → 29/07/1988

Series	Advances in Space Research
Number	7
Volume	10
ISSN	0273-1177

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title = "Waves generated by pulsed electron beams",

abstract = "During the Spacelab-2 flight of July, 1985, electron beams (1 keV, 100 mA) square-wave modulated at ELF and VLF were emitted from the space shuttle. The wave fields generated by the beam were monitored by a free-flying sub-satellite at distances up to 300 m perpendicular to the beam. The amplitude of the magnetic and electric fields were modulated by the spin of the satellite. This modulation allows the study of the wave polarization. Results for a 7 min duration beam sequence in which the beam was pulsed at 1.22 kHz are presented and compared with recent predictions for wave-fields stimulated by ideal helical electron beams propagating in a magnetized plasma. It is found that the predicted magnetic field amplitude of the first harmonic of the beam pulsing frequency (below the lower hybrid frequency) is in agreement with observations, however, the predicted and the observed polarizations are entirely different. For the higher harmonic components (above the lower hybrid frequency), theory predicts order of magnitude larger magnetic field amplitudes than observed. It is concluded that the theory does not adequately model the full distribution of the radiating current.",

author = "Torsten Neubert and K.J. Harker and P.M. Banks and E.G.D. Reeves and D.A. Gurnett",

year = "1990",

doi = "10.1016/0273-1177(90)90287-A",

language = "English",

isbn = "0-08-040164-3",

series = "Advances in Space Research",

publisher = "Pergamon Press",

number = "7",

pages = "137--142",

booktitle = "Active Experiments/Critical Ionization Velocity",

note = "Workshop of the Topical Meeting of the Interdisciplinary Commission of the COSPAR 27th Plenary Meeting : Active Experiments/Critical Ionization Velocity ; Conference date: 18-07-1988 Through 29-07-1988",

}

Neubert, T, Harker, KJ, Banks, PM, Reeves, EGD & Gurnett, DA 1990, Waves generated by pulsed electron beams. in Active Experiments/Critical Ionization Velocity. Pergamon Press, Advances in Space Research, no. 7, vol. 10, pp. 137-142, Workshop of the Topical Meeting of the Interdisciplinary Commission of the COSPAR 27th Plenary Meeting, Espoo, Finland, 18/07/1988. https://doi.org/10.1016/0273-1177(90)90287-A

TY - GEN

T1 - Waves generated by pulsed electron beams

AU - Neubert, Torsten

AU - Harker, K.J.

AU - Banks, P.M.

AU - Reeves, E.G.D.

AU - Gurnett, D.A.

N1 - Conference code: 27

PY - 1990

Y1 - 1990

N2 - During the Spacelab-2 flight of July, 1985, electron beams (1 keV, 100 mA) square-wave modulated at ELF and VLF were emitted from the space shuttle. The wave fields generated by the beam were monitored by a free-flying sub-satellite at distances up to 300 m perpendicular to the beam. The amplitude of the magnetic and electric fields were modulated by the spin of the satellite. This modulation allows the study of the wave polarization. Results for a 7 min duration beam sequence in which the beam was pulsed at 1.22 kHz are presented and compared with recent predictions for wave-fields stimulated by ideal helical electron beams propagating in a magnetized plasma. It is found that the predicted magnetic field amplitude of the first harmonic of the beam pulsing frequency (below the lower hybrid frequency) is in agreement with observations, however, the predicted and the observed polarizations are entirely different. For the higher harmonic components (above the lower hybrid frequency), theory predicts order of magnitude larger magnetic field amplitudes than observed. It is concluded that the theory does not adequately model the full distribution of the radiating current.

AB - During the Spacelab-2 flight of July, 1985, electron beams (1 keV, 100 mA) square-wave modulated at ELF and VLF were emitted from the space shuttle. The wave fields generated by the beam were monitored by a free-flying sub-satellite at distances up to 300 m perpendicular to the beam. The amplitude of the magnetic and electric fields were modulated by the spin of the satellite. This modulation allows the study of the wave polarization. Results for a 7 min duration beam sequence in which the beam was pulsed at 1.22 kHz are presented and compared with recent predictions for wave-fields stimulated by ideal helical electron beams propagating in a magnetized plasma. It is found that the predicted magnetic field amplitude of the first harmonic of the beam pulsing frequency (below the lower hybrid frequency) is in agreement with observations, however, the predicted and the observed polarizations are entirely different. For the higher harmonic components (above the lower hybrid frequency), theory predicts order of magnitude larger magnetic field amplitudes than observed. It is concluded that the theory does not adequately model the full distribution of the radiating current.

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DO - 10.1016/0273-1177(90)90287-A

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SP - 137

EP - 142

BT - Active Experiments/Critical Ionization Velocity

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T2 - Workshop of the Topical Meeting of the Interdisciplinary Commission of the COSPAR 27th Plenary Meeting

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ER -

Waves generated by pulsed electron beams

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Workshop

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