REVIEW ARTICLE The anomalous skin effect in gas discharge plasmas

Abstract. This paper contains a review of classical and recent works on the anomalous skin effect in gas discharge plasmas. Recently, interest in this problem has been generated by the introduction of inductively coupled plasma (ICP) sources operating at low gas pressures (0.1–50 mTorr). The near-collisionless operating regime corresponds to the conditions of the anomalous skin effect. The skin effect governs not only the distribution of the electromagnetic field but also the mechanism of electron heating and power absorption by the plasma. The finite dimensions of the plasma and magnetic fields as weak as the natural geomagnetic field play important roles under these conditions. The understanding of these phenomena is far from complete. We draw upon advances in the physics of metals (where the anomalous skin effect was discovered and thoroughly explored) to gain insight into discharge plasmas where many interesting phenomena are yet to be found. 1