Second harmonic electromagnetic emission via beam-driven Langmuir waves

2005 ◽  
Vol 12 (1) ◽  
pp. 012103-012103-15 ◽  
Author(s):  
B. Li ◽  
A. J. Willes ◽  
P. A. Robinson ◽  
I. H. Cairns
Keyword(s):  
Second Harmonic ◽  
Electromagnetic Emission ◽  
Langmuir Waves

Corrected Formula for the Polarization of Second Harmonic Plasma Emission

1980 ◽  
Vol 4 (1) ◽  
pp. 50-53 ◽  
Author(s):  
D. B. Melrose ◽  
G. A. Dulk ◽  
D. E. Gary
Keyword(s):  
Transverse Wave ◽  
Second Harmonic ◽  
Plasma Emission ◽  
Langmuir Waves

Second harmonic plasma emission is attributed to the coalescence of two Langmuir waves into a transverse wave.

scholarly journals A Relationship Between the Brightness Temperatures for Type III Bursts

1974 ◽  
Vol 57 ◽  
pp. 285-287
Author(s):  
D. B. Melrose
Keyword(s):  
Fundamental Frequency ◽  
Solar Phys ◽  
Second Harmonic ◽  
Intermediate Stage ◽  
Langmuir Waves ◽  
Type Iii ◽  
Brightness Temperatures ◽  
Two Stages

(Solar Phys.). The widely accepted emission mechanisms for type III bursts involve at least two stages. The first stage is the generation of Langmuir waves by the inferred stream of electrons. Emission at the fundamental frequency arises when these waves are scattered by thermal ions. Emission at the second harmonic arises when two Langmuir waves coalesce; however, the coalescence is possible only after an intermediate stage in which the distribution of Langmuir waves evolves towards isotropy due to scattering by thermal ions.

Dynamics of fundamental electromagnetic emission via beam-driven Langmuir waves

2005 ◽  
Vol 12 (5) ◽  
pp. 052324 ◽  
Author(s):  
B. Li ◽  
A. J. Willes ◽  
P. A. Robinson ◽  
I. H. Cairns
Keyword(s):  
Electromagnetic Emission ◽  
Langmuir Waves

scholarly journals Numerical studies on terahertz radiation generated from two-color laser pulse interaction with gas targets

2011 ◽  
Vol 29 (4) ◽  
pp. 447-452 ◽  
Author(s):  
H.W. Du ◽  
M. Chen ◽  
Z.M. Sheng ◽  
J. Zhang
Keyword(s):  
Intensity Ratio ◽  
Second Harmonic ◽  
Electromagnetic Emission ◽  
Current Theory ◽  
Particle In Cell ◽  
Neutral Gas ◽  
Ionization Model ◽  
The Difference ◽  
Gas Targets ◽  
Proper Values

AbstractBased upon the Ammosov-Delone-Krainov ionization model, it is shown that two-color laser interaction with neutral gas generates strong ionization currents, which lead to electromagnetic emission at terahertz frequency when the gas density is at proper values. The emission efficiency depends on the difference of the phases between the fundamental and its second harmonic. The intensity ratio between the two pulses also affects the emission strength. An optimum intensity ratio has been found within our parameter region. The above ionization current theory is in agreement with one-dimensional particle-in-cell simulations with field ionization included.

scholarly journals A new hydrodynamic analysis of double layers

1987 ◽  
Vol 5 (2) ◽  
pp. 269-286 ◽  
Author(s):  
M. P. Goldsworthy ◽  
F. Green ◽  
H. Hora
Keyword(s):  
Electric Fields ◽  
Second Harmonic ◽  
Fluid Model ◽  
Inhomogeneous Plasma ◽  
Macroscopic Model ◽  
Double Layers ◽  
Astrophysical Plasmas ◽  
Langmuir Waves ◽  
Hydrodynamic Description ◽  
Very High

A Genuine two-fluid model of plasmas with collisions permits the calculation of dynamic electric fields and double layers inside plasmas including oscillations and damping. For the first time a macroscopic model for coupling of electromagnetic and Langmuir waves was achieved with realistic damping. Starting points were laser produced plasmas showing very high dynamic electric fields in nonlinear force produced cavitons and inverted layers, in agreement with experiments. Applications for any inhomogeneous plasma as in laboratory or in astrophysical plasmas can then be followed up by a transparent hydrodynamic description. We find the rotation of plasmas in magnetic fields and a new second harmonic resonance. Explanation of inverted double layers, second harmonic emission from laser produced plasmas, and laser acceleration of charged particles by the very high fields of the double layers is given.

scholarly journals Second harmonic electromagnetic emission in a beam-driven plasma antenna

2019 ◽  
Vol 61 (5) ◽  
pp. 055005 ◽  
Author(s):  
V V Annenkov ◽  
E A Berendeev ◽  
E P Volchok ◽  
I V Timofeev
Keyword(s):  
Second Harmonic ◽  
Electromagnetic Emission ◽  
Plasma Antenna

Second harmonic electromagnetic emission via Langmuir wave coalescence

1996 ◽  
Vol 3 (1) ◽  
pp. 149-159 ◽  
Author(s):  
A. J. Willes ◽  
P. A. Robinson ◽  
D. B. Melrose
Keyword(s):  
Second Harmonic ◽  
Langmuir Wave ◽  
Electromagnetic Emission

scholarly journals Detection of Langmuir Solitons: Implications for Type III Burst Emission Mechanisms at 2ωPE

1996 ◽  
Vol 154 ◽  
pp. 195-198
Author(s):  
G. Thejappa ◽  
R.G. Stone ◽  
M.L. Goldstein
Keyword(s):  
Second Harmonic ◽  
Theoretical Models ◽  
Burst Source ◽  
Langmuir Waves ◽  
Type Iii ◽  
Source Regions ◽  
Envelope Solitons ◽  
Turbulence Regime ◽  
Solar Type ◽  
Langmuir Solitons

AbstractWe present the experimental verification of existing theoretical models of emission mechanisms of solar type III bursts at the second harmonic of the plasma frequency, ωpe. This study is based on the detection of Langmuir and envelope solitons by the Ulysses spacecraft inside three type III burst source regions. We show that the oscillating-two-stream instability, coherent radiation by Langmuir solitons and stochastic phase mixing of the Langmuir waves in the strong turbulence regime are the appropriate emission mechanisms at 2ωpe.

scholarly journals Evidence for four- and three-wave interactions in solar type III radio emissions

2013 ◽  
Vol 31 (8) ◽  
pp. 1417-1428 ◽  
Author(s):  
G. Thejappa ◽  
R. J. MacDowall ◽  
M. Bergamo
Keyword(s):  
Wave Packet ◽  
Second Harmonic ◽  
Wave Packets ◽  
Spectral Peak ◽  
Wave Number ◽  
Radio Bursts ◽  
Langmuir Waves ◽  
Type Iii ◽  
Primary Peak ◽  
Solar Type

Abstract. The high time resolution observations obtained by the STEREO/WAVES experiment show that in the source regions of solar type III radio bursts, Langmuir waves often occur as intense localized wave packets with short durations of only few ms. One of these wave packets shows that it is a three-dimensional field structure with WLneTe ~ 10−3, where WL is the peak energy density, and ne and Te are the electron density and temperature, respectively. For this wave packet, the conditions of the oscillating two-stream instability (OTSI) and supersonic collapse are satisfied within the error range of determination of main parameters. The density cavity, observed during this wave packet indicates that its depth, width and temporal coincidence are consistent with those of a caviton, generated by the ponderomotive force of the collapsing wave packet. The spectrum of each of the parallel and perpendicular components of the wave packet contains a primary peak at fpe, two secondary peaks at fpe ± fS and a low-frequency enhancement below fS, which, as indicated by the frequency and wave number resonance conditions, and the fast Fourier transform (FFT)-based tricoherence spectral peak at (fpe, fpe, fpe + fS, fpe − fS), are coupled to each other by the OTSI type of four-wave interaction (fpe is the local electron plasma frequency and fS is the frequency of ion sound waves). In addition to the primary peak at fpe, each of these spectra also contains a peak at 2fpe, which as indicated by the frequency and wave number resonance conditions, and the wavelet-based bicoherence spectral peak at (fpe, fpe), appears to correspond to the second harmonic electromagnetic waves generated as a result of coalescence of oppositely propagating sidebands excited by the OTSI. Thus, these observations for the first time provide combined evidence that (1) the OTSI and related strong turbulence processes play a significant role in the stabilization of the electron beam, (2) the coalescence of the oppositely propagating up- and down-shifted daughter Langmuir waves excited by the OTSI probably is the emission mechanism of the second harmonic radiation, and (3) the Langmuir collapse follows the route of OTSI in some of the type III radio bursts.

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