scholarly journals Condensate Formation in Collisionless Plasma

2021 ◽  
Vol 9 ◽  
Author(s):  
R. A. Treumann ◽  
Wolfgang Baumjohann
Keyword(s):  
High Temperature ◽  
Background Noise ◽  
Collisionless Plasma ◽  
Debye Length ◽  
Magnetic Mirror ◽  
Perpendicular Direction ◽  
Correlation Lengths ◽  
Ion Acoustic ◽  
Condensate Formation ◽  
Parallel Direction

Particle condensates in general magnetic mirror geometries in high-temperature plasmas may be caused by a discrete resonance with thermal ion-acoustic background noise near mirror points. The resonance breaks the bounce symmetry, temporally locking the particles to the resonant wavelength. The relevant correlation lengths are the Debye length in the parallel direction and the ion gyroradius in the perpendicular direction.

PLT reaches high temperature in a collisionless plasma

Physics Today ◽  
1978 ◽  
Vol 31 (11) ◽  
pp. 17-20
Author(s):  
Gloria B. Lubkin
Keyword(s):  
High Temperature ◽  
Collisionless Plasma

scholarly journals Observational support for the electron mirror mode: AMPTE-IRM and Equator-S measurements in the magnetosheath

2018 ◽  
Author(s):  
Rudolf A. Treumann ◽  
Wolfgang Baumjohann
Keyword(s):  
High Temperature ◽  
Collisionless Plasma ◽  
Recent Theory ◽  
Dayside Magnetopause ◽  
Mirror Mode

Abstract. Based on AMPTE-IRM and Equator-S observations in the magnetosheath near the dayside magnetopause, we provide observational support for a recent theory by Noreen et al. (2017) of the contribution of the electron mirror instability to the evolution of mirror modes in the high-temperature anisotropic collisionless plasma of the magnetosheath.

scholarly journals Stimulated Brillouin backscattering of a ring-rippled laser beam in collisionless plasma

2015 ◽  
Vol 33 (3) ◽  
pp. 499-509 ◽  
Author(s):  
Gunjan Purohit ◽  
Priyanka Rawat
Keyword(s):  
Laser Beam ◽  
Narrow Range ◽  
Brillouin Scattering ◽  
Collisionless Plasma ◽  
Plasma Parameters ◽  
Ion Acoustic Wave ◽  
Coupled Equations ◽  
Ion Acoustic ◽  
Paraxial Ray ◽  
Stimulated Brillouin

AbstractThe effect of the propagation of a ring-rippled laser beam in the presence of relativistic and ponderomotive non-linearities on the excitation of ion-acoustic wave (IAW) and resulting stimulated Brillouin backscattering in collisionless plasma at relativistic powers is studied. To understand the nature of propagation of the ring ripple-like instability, a paraxial-ray approach has been invoked in which all the relevant parameters correspond to a narrow range around the irradiance maximum of the ring ripple. Modified coupled equations for growth of ring ripple in the plasma, generations of IAW and back-stimulated Brillouin scattering (SBS) are derived from fluid equations. These coupled equations are solved analytically and numerically to study the intensity of ring-rippled laser beam and excited IAW as well as back reflectivity of SBS in the plasma for various established laser and plasma parameters. It is found that the back reflectivity of SBS is enhanced due to the strong coupling between ring-rippled laser beam and the excited IAW. The results also show that the back reflectivity of SBS reduce for higher intensity of the laser beam.

Longitudinal waves in a perpendicular collisionless plasma shock: II. Vlasov ions

1970 ◽  
Vol 4 (4) ◽  
pp. 753-760 ◽  
Author(s):  
S. Peter Gary
Keyword(s):  
Collisionless Plasma ◽  
Maximum Growth ◽  
Zero Magnetic Field ◽  
Linear Dispersion ◽  
Electrostatic Waves ◽  
Longitudinal Waves ◽  
Acoustic Instability ◽  
Ion Acoustic ◽  
Plasma Shock ◽  
Vlasov Plasma

This paper presents an analysis of the linear dispersion relation for electrostatic waves in a Vlasov plasma of unmagnetized, Maxwellian ions and magnetized, Maxwellian electrons. The electrons undergo E × B and ∇B drifts, and the electron β is small. For propagation in the perpendicular direction, maximum growth rates can be substantially larger than those of the zero magnetic field ion acoustic instability. For propagation outside a few degrees from the perpendicular the dispersion characteristics are essentially those of the ion acoustic instability.

An exact electrostatic shock solution for a collisionless plasma

1970 ◽  
Vol 4 (3) ◽  
pp. 549-561 ◽  
Author(s):  
A. Smith
Keyword(s):  
Exact Solution ◽  
Steady State ◽  
Energy Equation ◽  
Collisionless Plasma ◽  
Debye Length ◽  
Elementary Functions ◽  
One Dimensional ◽  
Particle Distributions ◽  
Vlasov Equations ◽  
Shock Solution

An exact solution to the steady-state Vlasov equations and Poisson's equation for a one-dimensional plasma of electrons and protons is obtained by splitting the energy equation into two integral equations for the trapped particle distributions. This solution has the properties that the number densities and electric potential are moiiotonic functions of space and do most of their changing over a distance of the order of the Debye length for electrons. The distributions are everywhere differentiable in phase space and are Maxwellian-like, and in terms of elementary functions. Evidence is given to support stability for restricted shock strengths.

Relativistic formulation for non-linear waves in a non-uniform plasma

1968 ◽  
Vol 2 (2) ◽  
pp. 257-281 ◽  
Author(s):  
D. S. Butler ◽  
R. J. Gribben
Keyword(s):  
Mathematical Formulation ◽  
Collisionless Plasma ◽  
Debye Length ◽  
Type Equation ◽  
Distribution Functions ◽  
Small Scale ◽  
Relativistic Limit ◽  
Background Distribution ◽  
Non Linear ◽  
Special Case

The mathematical formulation for the problem of non-linear oscillations in a self-consistent, non-uniform, collisionless plasma is considered. The fully nonlinear treatment illuminates the effect of the wave on the background distribution of the plasma through which it is passing. It is assumed that, although the overall non-uniformity may be large, significant changes occur only over time or length scales which are large compared with the plasma period or Debye length respectively. Exclusion of secular terms from the solution leads to a Liouvile type equation, which must be satisfied by the background distribution, and to propagation laws for the waves.The theory is restricted to almost one-dimensional electrostatic waves and a general presentation is given from a relativistically-invariant point of view. Then the equations are derived in terms of physical variables for the special case in which: (i) the distribution functions and electrostatic potential depend on one space co-ordinate (that of propagation of the wave) and the former on the corresponding particle velocity component only, (ii) the wave is slowly-varying only with respect to this co-ordinate and time, and (iii) the magnetic field is zero. Finally, the non-relativistic limit of this case is considered in more detail. The boundary conditions satisfied by the distribution functions are discussed and this leads to the conclusion that in some circumstances thin sheets of probability fluid are formed in phase space and the background distribution cannot be strictly defined. This motivates a reformulation and subsequent re-solution of the problem (for this non-relativistic special case) in terms of weak functions, corresponding to the physical assumption of the presence of a small-scale mixing mechanism, which is excited by and smears the sheeted distribution but is otherwise dormant.The results of the investigation are given as a system of differentio-integral equations which must be solved if necessary conditions for the absence of nonsecular solutions (of the Vlasov and Maxwell equations) are to be satisfied. No solution of this system is attempted here.

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