m=+/-1 and m=+/-2 mode helicon wave excitation

Abstract

The characteristics of plasma produced by plane polarized m = +/-1 and m = +/-2 mode helicon waves were investigated for the first time. Plane polarized m = ii and m = +/-2 mode helicon waves were mainly excited using a Nagoya type III antenna and a quadrupole antenna, respectively. Two-dimensional cross-field measurements of ArII optical emission induced by hot electrons were made to investigate the RF power deposition. The components of the wave magnetic field measured with a magnetic probe were compared with the field profiles computed for the m = +/-1 and m = +/-2 modes. Two and four high intensity plasma columns were observed for the m = +/-1 and m = +/-2 modes, respectively. These columns were located at the regions between the antenna legs. The radial profiles of the wave magnetic field were in good agreement with computations.