Electron Bernstein wave generation in a linear plasma system

Electron Bernstein wave (EBW) generation via mode conversion is observed in a short cylindrical electron cyclotron resonance (ECR) plasma system. ECR plasma with input microwave power varying from 160 to 800 W is produced at an operating pressure of 10-3 mbar with hydrogen gas with a maximum plasma density of 3.1x1010 cm-3 at the center and plasma temperature of 10 eV. The axial magnetic field required for ECR in the system is produced by two identical magnetic coils arranged in the Helmholtz configuration. The fundamental ECR surface (B=875 G) is located at the geometrical center of the plasma system. Microwaves of 2.45±0.02 GHz from a magnetron in TE10 mode are launched radially to have extraordinary (X) wave in plasma. The EBW is observed to be generated at the upper hybrid resonance layer at a distance of 2 cm from the center towards the microwave source. The EBW is assumed to be generated through X-B mode conversion which is inferred by the observation of the parametric decay of the incident wave. The experimental results pertaining to the EBW detection and characterization are discussed in this paper