Absorption of left-polarized microwaves in electron cyclotron resonance plasmas

Left-polarized (m = -1) microwaves launched in an electron cyclotron resona nce discharge are found to be absorbed efficiently, contrary to expectation . Investigation of microwave penetration into the plasma reveals the presen ce of large-amplitude, long-wavelength waves, along with bursts of short-wa velength waves localized mostly near the peaks of the long waves. By compar ison with the theory developed, these waves are identified as the guided-wa ve modes of the system. The long waves are usually m = -1 waves even when m = +1 waves are launched, while the short waves comprise a mixture of m = f l modes. The absorption results are interpreted in terms of polarization re versal of these waves within the plasma. (C) 1998 Elsevier Science B.V.