Helicon Wave Measurements in an Inductively Coupled Magnetoplasma

Abstract

Small-amplitude test waves at 30-100 MHz are externally excited in an inductive rf plasma for a magnetic field of rv100 G, to obtain a full dispersion relation for helicon waves. Measured wavelengths agree well with theoretical ones, not only for the test waves but also for largeamplitude principal waves at the discharge frequency of 13·56 MHz. Absolute measurements of the radial magnetic field B; of the large-amplitude helicon wave are carried out, and the r, q and z components of the wave electric field are estimated to be E; rv Eo rv 8 V cm-1 and Ez rv 0·7Vcm-1 at an rf power of 800 W.