Wave Properties in a Weakly‐Magnetized Plasma Produced by Rotating Radio‐Frequency Electromagnetic Fields

Ar plasmas are produced by using spatially‐ and temporally‐rotating radio‐frequency (fRF) electromagnetic fields in very weak uniform magnetic fields. The plasma density is observed to increase greatly compared with ICP mode when the RF fields rotate in the electron‐diamagnetic direction and fce/fRF ∼ 4 is satisfied (fce: electron cyclotron frequency). Then the Trivelpiece‐Gould wave with large amplitude propagates and damps toward the downstream. The existence of the damped wave appears to contribute to the efficient plasma production.