Interaction of powerful laser pulse with magnetized plasma

Abstract

In this paper the generation of electrostatic wake field and electron acceleration in this field by intense laser pulse propagating in plasma in the presence of external magnetic field is investigated. It is shown that if the change in the laser pulse wave amplitude (approximation of the constant laser pulse wave field) is not taken into account, it is possible by switching to Lagrangian variables to reduce the system of equations describing excitation of the wake field and electron acceleration to a simplified system of ordinary differential equations (ODE), which can be easily integrated. This makes it possible to find the energy, transferred to electron oscillations in the wake field for different angles between the direction of laser pulse propagation and magnetic field. Stability of the laser pulse propagating with arbitrary angle to external magnetic field towards excitation of parametric and decay instabilities with involvement of upper hybrid and lower hybrid waves is investigated, as well. Equations describing these instabilities are derived and growth rates are found analytically for a small amplitude wake field and with the help of numerical calculations in the case of the finite wake field amplitude.

Nonlinear modulation of an extraordinary wave under the conditions of parametric decay

“…In the presence of a strong confining magnetic field, new resonances appear in a dense plasma and the frequency range where radiation parametrically affects the plasma expands. The heating of the X pinch plasma by a laser pulse can serve as an example of such a situation [2]. In this case, the energy of accelerated electrons depends on the angle between the wave vector and the magnetic field and reaches its maximum value when an extraor dinary wave is excited in the plasma.…”

“…In cold plasma, an extraordinary electromagnetic wave decays into two half frequency waves [2,7]. In each particular parametric resonance, the efficiency of the process depends on the instability growth rate, which is deter mined by a self consistent set of linearized nonlinear equations and is proportional to the amplitude of the pump wave.…”

“…However, theoretical analysis based on the linear (with respect to the amplitude of the pump wave) growth rates of parametric instabilities [2][3][4][5][6][7] describes only the initial stage of decay and fails to provide infor mation on the interaction of finite amplitude wave packets with plasma. The strongly nonlinear stage of the parametric decay of the original wave and the non linear saturation of the secondary wave in plasma can be analyzed using numerical simulation [7].…”

Laser Acceleration of Electrons in Magnetized Collisionless Plasma

“…A laser pulse propagating in a plasma in the presence of an external magnetic field can generate an electrostatic wakefied resulting in electron acceleration in the plasma [8]. The acceleration of a non-relativistic electron in a magnetized plasma is given by [9]: (7) where ω c is the cyclotron frequency,   vt  is the velocity of the electron and   pt  is its displacement.…”

Simulation study of wake field excitation in interaction of intense laser and magnetized plasma: Half-sine pulse shape (HSPS) and trapezoid pulse shape (TPS)

“…They reported that there is a different effect on self-focusing corresponding to a different angle and intensity. Krasovitskii et al have studied the interaction of powerful laser pulse with plasma and generated wake field in the presence of an external magnetic field [26]. They have shown that the transferred energy to electron oscillations in the wake field is different for various angles between the direction of laser pulse propagation and magnetic field.…”