Incidence angle dependence of Langmuir turbulence and artificial ionospheric layers driven by high-power HF-heating

B. Eliasson, G. Milikh, X. Shao, E. V. Mishin, K. Papadopoulos

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We have numerically investigated the development of strong Langmuir turbulence
(SLT) and associated electron acceleration at different angles of incidence of ordinary (O) mode pump waves. For angles of incidence within the Spitze cone, the turbulence initially develops within the first maximum of the Airy pattern near the plasma resonance altitude. After a few milliseconds, the turbulent layer shifts downwards by about 1 km. For injections outside the Spitze region, the turning point of the pump wave is at lower altitudes. Yet, an Airy-like pattern forms here, and the turbulence development is quite similar to that for injections within the Spitze. SLT leads to the acceleration of 10–20 eV electrons that ionize the neutral gas thereby creating artificial ionospheric layers. Our numerical modeling shows that most efficient electron acceleration and ionization occur at angles between the magnetic and geographic zenith, where SLT dominates over weak turbulence. Possible effects of the focusing of the electromagnetic beam on magnetic field-aligned density irregularities and the finite heating beam width at the magnetic zenith are also discussed. The results have relevance to ionospheric heating experiments using ground-based, high-power radio transmitters to heat the overhead plasma, where recent observations of artificial ionization layers have been made.
LanguageEnglish
Article number415810201
Number of pages16
JournalJournal of Plasma Physics
Volume81
Issue number02
Early online date6 Nov 2014
DOIs
Publication statusPublished - Apr 2015

Fingerprint

Langmuir turbulence
ionospherics
electron acceleration
incidence
turbulence
zenith
heating
radio transmitters
ionospheric heating
pumps
injection
ionization
plasma resonance
low altitude
neutral gases
irregularities
cones
electromagnetism
heat
shift

Keywords

  • ionospheric turbulence
  • strong Langmuir turbulence
  • electron acceleration

Cite this

@article{43c5d7d39dd64619937ea851f2ec2726,
title = "Incidence angle dependence of Langmuir turbulence and artificial ionospheric layers driven by high-power HF-heating",
abstract = "We have numerically investigated the development of strong Langmuir turbulence(SLT) and associated electron acceleration at different angles of incidence of ordinary (O) mode pump waves. For angles of incidence within the Spitze cone, the turbulence initially develops within the first maximum of the Airy pattern near the plasma resonance altitude. After a few milliseconds, the turbulent layer shifts downwards by about 1 km. For injections outside the Spitze region, the turning point of the pump wave is at lower altitudes. Yet, an Airy-like pattern forms here, and the turbulence development is quite similar to that for injections within the Spitze. SLT leads to the acceleration of 10–20 eV electrons that ionize the neutral gas thereby creating artificial ionospheric layers. Our numerical modeling shows that most efficient electron acceleration and ionization occur at angles between the magnetic and geographic zenith, where SLT dominates over weak turbulence. Possible effects of the focusing of the electromagnetic beam on magnetic field-aligned density irregularities and the finite heating beam width at the magnetic zenith are also discussed. The results have relevance to ionospheric heating experiments using ground-based, high-power radio transmitters to heat the overhead plasma, where recent observations of artificial ionization layers have been made.",
keywords = "ionospheric turbulence, strong Langmuir turbulence, electron acceleration",
author = "B. Eliasson and G. Milikh and X. Shao and Mishin, {E. V.} and K. Papadopoulos",
note = "{\circledC} Cambridge University Press 2015",
year = "2015",
month = "4",
doi = "10.1017/S0022377814000968",
language = "English",
volume = "81",
journal = "Journal of Plasma Physics",
issn = "0022-3778",
number = "02",

}

Incidence angle dependence of Langmuir turbulence and artificial ionospheric layers driven by high-power HF-heating. / Eliasson, B.; Milikh, G.; Shao, X.; Mishin, E. V.; Papadopoulos, K.

In: Journal of Plasma Physics, Vol. 81, No. 02, 415810201, 04.2015.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Incidence angle dependence of Langmuir turbulence and artificial ionospheric layers driven by high-power HF-heating

AU - Eliasson, B.

AU - Milikh, G.

AU - Shao, X.

AU - Mishin, E. V.

AU - Papadopoulos, K.

N1 - © Cambridge University Press 2015

PY - 2015/4

Y1 - 2015/4

N2 - We have numerically investigated the development of strong Langmuir turbulence(SLT) and associated electron acceleration at different angles of incidence of ordinary (O) mode pump waves. For angles of incidence within the Spitze cone, the turbulence initially develops within the first maximum of the Airy pattern near the plasma resonance altitude. After a few milliseconds, the turbulent layer shifts downwards by about 1 km. For injections outside the Spitze region, the turning point of the pump wave is at lower altitudes. Yet, an Airy-like pattern forms here, and the turbulence development is quite similar to that for injections within the Spitze. SLT leads to the acceleration of 10–20 eV electrons that ionize the neutral gas thereby creating artificial ionospheric layers. Our numerical modeling shows that most efficient electron acceleration and ionization occur at angles between the magnetic and geographic zenith, where SLT dominates over weak turbulence. Possible effects of the focusing of the electromagnetic beam on magnetic field-aligned density irregularities and the finite heating beam width at the magnetic zenith are also discussed. The results have relevance to ionospheric heating experiments using ground-based, high-power radio transmitters to heat the overhead plasma, where recent observations of artificial ionization layers have been made.

AB - We have numerically investigated the development of strong Langmuir turbulence(SLT) and associated electron acceleration at different angles of incidence of ordinary (O) mode pump waves. For angles of incidence within the Spitze cone, the turbulence initially develops within the first maximum of the Airy pattern near the plasma resonance altitude. After a few milliseconds, the turbulent layer shifts downwards by about 1 km. For injections outside the Spitze region, the turning point of the pump wave is at lower altitudes. Yet, an Airy-like pattern forms here, and the turbulence development is quite similar to that for injections within the Spitze. SLT leads to the acceleration of 10–20 eV electrons that ionize the neutral gas thereby creating artificial ionospheric layers. Our numerical modeling shows that most efficient electron acceleration and ionization occur at angles between the magnetic and geographic zenith, where SLT dominates over weak turbulence. Possible effects of the focusing of the electromagnetic beam on magnetic field-aligned density irregularities and the finite heating beam width at the magnetic zenith are also discussed. The results have relevance to ionospheric heating experiments using ground-based, high-power radio transmitters to heat the overhead plasma, where recent observations of artificial ionization layers have been made.

KW - ionospheric turbulence

KW - strong Langmuir turbulence

KW - electron acceleration

UR - http://journals.cambridge.org/action/displayJournal?jid=PLA

U2 - 10.1017/S0022377814000968

DO - 10.1017/S0022377814000968

M3 - Article

VL - 81

JO - Journal of Plasma Physics

T2 - Journal of Plasma Physics

JF - Journal of Plasma Physics

SN - 0022-3778

IS - 02

M1 - 415810201

ER -