Experimental and theoretical study of the microwaves transmission through the plasma structures and layers in a constant magnetic field

Abstract

The possibility of significant improvement transmission conditions of microwave radiation passing through a homogeneous quasi-neutral plasma layer in the constant magnetic field B0 is considered. The study based on 1D analysis was conducted for layers with concentration Np = 1017-1019 m-3 and collision frequency of electrons with molecules ν = 1010-1011 s-1 in the wavelength range λ = 1-10 cm. For different values of plasma parameters Np and ν the dependences of the magnetic induction values B0(λ, α, |D|cr), reducing a transmitted wave amplitude attenuation to a specified level (in this case, |D|cr = 3 dB) were obtained. Analyzed the influence of the angle between vectors B0 and k (wave vector) on the amplitude AT and, hence, on the value of B0(λ, α, |D|cr), revealed the optimal conditions of the field B0 orientation relative to the direction of electromagnetic waves propagation. Experimentally investigated the influence of a constant magnetic field B0 on the attenuation degree of microwave radiation (f = 13 GHz) in a various types plasma structures and in the plasma layers. The experiments were carried out in air at pressures P = 70-500 Torr. A marked increase in the amplitude of the transmitted wave in presence of constant magnetic field was indicated.