An analytical investigation of the optical mixing of two laser beams of identical frequencies in a spatially homogeneous collisionless plasma

1976 ◽  
Vol 54 (24) ◽  
pp. 2387-2395
Author(s):  
Orestes Spyrou ◽  
Jochen Meyer
Keyword(s):  
Electric Field Intensity ◽  
Collisionless Plasma ◽  
Charged Particles ◽  
Elliptic Functions ◽  
Particle Dynamics ◽  
Analytical Investigation ◽  
Laser Beams ◽  
Wave Number ◽  
Optical Mixing ◽  
Spatially Homogeneous

Two laser beams of the same frequency and intensity propagating in opposite directions are mixed in a uniform collisionless plasma.A standing longitudinal wave of wave number k0 = 2kL (kL being the wave number of one of the lasers) is excited and traps charged particles. Including trapped particle dynamics and making use of the properties of the Jacobi elliptic functions, an expression for the power P(t) and the energy. ΔU0 absorbed by the plasma electrons is derived. It is found that the power varies sinusoidally with time. Then the energy density ΔU0 is plotted as a function of the variable E10/kL, E10 being the electric field intensity of the lasers, and the validity of the results is discussed.

scholarly journals Particle Acceleration and Radiation in Magnetospheres of Collapsing Stars

2000 ◽  
Vol 195 ◽  
pp. 403-406
Author(s):  
V. Kryvdyk
Keyword(s):  
Magnetic Fields ◽  
Energy Distribution ◽  
Power Law ◽  
Charged Particles ◽  
Particle Dynamics ◽  
Initial Energy ◽  
Particle Energy ◽  
Radiation Fluxes ◽  
Nonthermal Emission ◽  
Initial Power

Particle dynamics and nonthermal emission therefrom in the magnetospheres of collapsing stars with initial dipole magnetic fields and a certain initial energy distribution of charged particles (power-law, relativistic Maxwell, and Boltzmann distributions) are considered. The radiation fluxes are calculated for various collapsing stars with initial dipole magnetic fields and an initial power-law particle energy distribution in the magnetosphere. The effects can be observed by means of modern instruments.

TURBULENT DIFFUSION OF TEST PARTICLES IN STRONGLY MAGNETIZED PLASMAS

1991 ◽  
Vol 05 (08) ◽  
pp. 1243-1262 ◽  
Author(s):  
MAURIZIO OTTAVIANI ◽  
MARCO PETTINI
Keyword(s):  
Electric Field ◽  
Equations Of Motion ◽  
Charged Particles ◽  
Mean Square Displacement ◽  
Wave Model ◽  
Particle Dynamics ◽  
Suitable Parameter ◽  
Test Particles ◽  
The Mean ◽  
Parameter Values

The motion of charged particles is described in the presence of a strong magnetic field and of an electric field made of three spatial Fourier modes whose amplitudes vary in time. The dynamics of the wave amplitudes is governed by a model of three interacting drift waves. For suitable parameter values of the three-wave model, chaotic solutions are found so that the Eulerian electric field is made of three turbulent modes. The E × B motion is described for charged particles in the guiding center approximation, which brings to nonlinear Hamiltonian equations of motion. The Hamiltonian (that coincides with the electric potential) is explicitly time-dependent through the temporal variation of the mode-amplitudes of the electric field, this fact is at the origin of the intrinsic chaoticity of particle dynamics (lagrangian chaos). Diffusive behaviour of particle trajectories is due to their intrinsic chaoticity and thus it is of non-collisional origin. Some results are reported concerning the particle dynamics when the Eulerian electric field is either quasi-periodically or chaotically varying in time. In particular, one finds different diffusion laws in the two cases (anomalous and classical respectively). The scaling behaviour of the diffusion coefficients (when the mean square displacement grows linearly in time) is reported. A simple stochastic model is also used to account for some of the observed features of particle diffusion.

scholarly journals On the exploration of graphical and analytical investigation of effect of critical beam power on self-focusing of cosh-Gaussian laser beams in collisionless magnetized plasma

2018 ◽  
Vol 36 (2) ◽  
pp. 254-260 ◽  
Author(s):  
T. U. Urunkar ◽  
S. D. Patil ◽  
A. T. Valkunde ◽  
B. D. Vhanmore ◽  
K. M. Gavade ◽  
...  
Keyword(s):  
Differential Equation ◽  
Turning Points ◽  
Beam Width ◽  
Analytical Investigation ◽  
Graphical Analysis ◽  
Magnetized Plasma ◽  
Laser Beams ◽  
Beam Power ◽  
Equation Approach ◽  
Self Focusing

AbstractThe paper gives graphical and analytical investigation of the effect of critical beam power on self-focusing of cosh-Gaussian laser beams in collisionless magnetized plasma under ponderomotive non-linearity. The standard Akhmanov's parabolic equation approach under Wentzel–Kramers–Brillouin (WKB) and paraxial approximations is employed to investigate the propagation of cosh-Gaussian laser beams in collisionless magnetized plasma. Especially, the concept of numerical intervals and turning points of critical beam power has evolved through graphical analysis of beam-width parameter differential equation of cosh-Gaussian laser beams. The results are discussed in the light of numerical intervals and turning points.

scholarly journals Kinematical relations at nonlinear laser field: Free electron interactions

1990 ◽  
Vol 8 (3) ◽  
pp. 451-459 ◽  
Author(s):  
F. F. Körmendi
Keyword(s):  
Particle Acceleration ◽  
Charged Particle ◽  
Kinetic Parameters ◽  
Free Electron ◽  
Nonlinear Interaction ◽  
Laser Field ◽  
Frequency Conversion ◽  
Charged Particles ◽  
Laser Beams ◽  
Electron Interactions

Kinematical relations of nonlinear interaction of laser beams with free charged particles are analyzed. General expressions are found for the number of scattered photons as a function of the number of simultaneously absorbed and/or emitted photons and the kinetic parameters of the charged particle-photon system. The results are applied to the processes of particle acceleration by lasers, frequency conversion, solitonic propagation, and others.

Collisionless damping of plasma waves as a real physical phenomenon does not exist

2014 ◽  
Vol 6 (3) ◽  
pp. 1291-1296
Author(s):  
V. N. Soshnikov
Keyword(s):  
Energy Conservation ◽  
Dispersion Equation ◽  
Physical Phenomenon ◽  
Harmonic Wave ◽  
Collisionless Plasma ◽  
Plasma Waves ◽  
Wave Number ◽  
Erroneous Statement ◽  
Complex Dispersion

Trivial logic of collisionless plasma waves is reduced to using complex exponentially damping/growing wave functions to obtain a complex dispersion equation for their wave number 1 k and the decrement/increment 2 k (for a given real frequency  and complex wave number k  k1  ik2 ), whose solutions are ghosts 1 2 k , k which do not have anything to do at 2 k  0 with the real solution of the dispersion equation for the initial exponentially damping/growing real plasma waves with the physically observable quantities 1 2 k , k , for which finding should be added, in this case, the second equation of the energy conservation law. Using a complex dispersion equation for the simultaneous determination of 1 k and 2 k violates the law of energy conservation, leads to a number of contradictions, is logical error, and finally also the mathematical error leading to both erroneous statement on the possible existence of exponentially damping/growing harmonic wave solutions and to erroneous values 1 k and 2 k . Mathematically correct conclusion about the damping/growing of virtual complex waves of collisionless plasma is wrongly attributed to the actual real plasma waves.

Gestural Articulations of Embodied Spatiality

2013 ◽  
Vol 5 (4) ◽  
pp. 17-47
Author(s):  
Lai Har Judy Lee ◽  
Yam San Chee
Keyword(s):  
Charged Particle ◽  
Charged Particles ◽  
Particle Dynamics ◽  
Frame Of Reference ◽  
Sense Making ◽  
Game Based Learning ◽  
Design Based Research ◽  
3D Game ◽  
Electric And Magnetic Fields ◽  
Game Environment

The work described in this paper is part of a design-based research involving the use of a game-based learning curriculum to foster students' understanding of physics concepts and principles governing the motion of charged particles in electric and magnetic fields. Students engaged in game-play and discussed the dynamics of the charged particles within the 3D game environment. The discussion sessions were video-recorded and an analysis was carried out on the gestures used by a group of students attempting to generalize their observations of the phenomena. The students’ gestures were analyzed to gain insights on their embodied sense-making of charged particle dynamics. The analysis showed that the students used gestures to (1) establish a shared frame of reference, (2) enact embodied game experience, and (3) enable the development of new understanding that surpasses their own existing vocabulary. Implications are discussed with regard to how teachers may take students’ gestures into account when facilitating the development of concepts with a strong visuo-spatial core.

Gestural Articulations of Embodied Spatiality

2015 ◽  
pp. 233-256
Author(s):  
Lai Har Judy Lee ◽  
Yam San Chee
Keyword(s):  
Charged Particle ◽  
Magnetic Fields ◽  
Charged Particles ◽  
Particle Dynamics ◽  
Frame Of Reference ◽  
Game Based Learning ◽  
Design Based Research ◽  
3D Game ◽  
Electric And Magnetic Fields ◽  
Game Environment

The work described in this paper is part of a design-based research involving the use of a game-based learning curriculum to foster students' understanding of physics concepts and principles governing the motion of charged particles in electric and magnetic fields. Students engaged in game-play and discussed the dynamics of the charged particles within the 3D game environment. The discussion sessions were video-recorded and an analysis was carried out on the gestures used by a group of students attempting to generalize their observations of the phenomena. The students' gestures were analyzed to gain insights on their embodied sense-making of charged particle dynamics. The analysis showed that the students used gestures to (1) establish a shared frame of reference, (2) enact embodied game experience, and (3) enable the development of new understanding that surpasses their own existing vocabulary. Implications are discussed with regard to how teachers may take students' gestures into account when facilitating the development of concepts with a strong visuo-spatial core.

Sign in / Sign up

Export Citation Format

Share Document