The efficient inject of high microwave powers into the overdense magnetoactive plasma in the waveguide

On the boundary vacuum — a dense magnetoactive plasma, an incident RHCP (right hand circularly polarized) wave is strongly reflected if ₀ ² / ² 1 and _ce/ > 1;, ₀, _ce are the ncident wave frequency, the plasma frequency and the electron cyclotron frequency, respectively. This reflection strongly lowers the efficiency of the plasma heating by microwaves. Our experimental study shows that a suitable matching system consisting of dielectric plates, placed in front of the plasma, can ensure practically complete transfer of the RHCP wave energy into a dense plasma. The experiment was carried out in the S band waveguide (=12·7 cm) with the power of the order of l kW.The authors wish to thank to the director of the Institute of Plasma Physics Dr. J.Váa for his interest in this work.