Dielectric Characteristics for Radio Frequency Waves in a Laboratory Dipole Plasma

Abstract

Transverse and parallel dielectric permittivity elements have been derived for radio frequency waves in a laboratory dipole magnetic field plasma. Vlasov equation is resolved for both the trapped and untrapped particles as a boundary value problem to define their separate contributions to the dielectric tensor components. To estimate the wave power absorbed in the plasma volume the perturbed electric field and current density components are decomposed in a Fourier series over the poloidal angle. In this case, the dielectric characteristics can be analyzed independently of the solution of the Maxwell's equations. As usual, imaginary part of the parallel permittivity elements is necessary to estimate the electron Landau damping of radio frequency waves, whereas imaginary part of the transverse permittivity elements is important to estimate the wave dissipation by the cyclotron resonances. Computations of the imaginary part of the parallel permittivity elements are carried out in a wide range of the wave frequencies.

Cyclotron wave instabilities in axisymmetric mirror-trapped plasmas with anisotropic temperature

“…Solving equation (11), to describe the bounce motion of the trapped particles, it is convenient to introduce the new time-like variable τ (ς), instead of ς :…”

“…These instabilities in the twodimensional (2D) axisymmetric traps, such as LDX plasma [12], should be described in the scope of the 2D kinetic wave theory by solving Maxwell's equations with a suitable kinetic dielectric tensor. Moreover, describing the wave-particle interaction in the laboratory dipole plasma, in contrast to straight mirror traps and Earth's magnetosphere, we should take into account that there are two entirely different groups of the so-called trapped and untrapped particles [11]. In this paper, we derive the dispersion relations of the fieldaligned waves in the LDX-like plasma having the energetic particles, e.g.…”

“…In this paper we consider and derive the dispersion relations using a self-consistent kinetic approach for the left-hand and right-hand polarized waves in the three simplest twodimensional (2D) axisymmetric plasma models: (1) straight mirror trap [9], (2) point dipole magnetosphere [10] and (3) levitated laboratory dipole magnetosphere [11].…”

Cyclotron Electromagnetic Instabilities in a Laboratory Dipole Magnetospheric Plasma with bi-Kappa Distributions

“…The 2D steady-state magnetic field is modeled by a laboratory dipole approximation [23,24] accounting for a finite radius of the current-ring creating the magnetic dipole. A 2D axisymmetric LDM plasma, schematically shown in Fig.…”

“…In this case the dispersion and stability properties need to be described in the frame of a 2D kinetic wave theory implying a specific dielectric tensor. Moreover, the wave-particle interactions should take into account that in a LDM plasma there are two entirely different groups of the so-called trapped and untrapped particles [23,24]. In the inner Earth's magnetosphere only trapped particles can exist bouncing along the geomagnetic field lines.…”