A study on m=1 mode helicon wave propagation in a weakly magnetized inductively coupled plasma source

Summary form only given. Helicon wave generation in weakly magnetized inductively coupled plasmas (ICPs) with a conducting boundary has been issued in this experiment. the characteristics of a helicon wave coupled with various antennas (one turn loop antenna, two turn loop antenna, and modified Nagoya. type antenna) and a conducting boundary was studied measurements were carried out in a weakly magnetized ICP (500 mm in dia and 600 mm in length). Plasma densities were 10/sup 10/-10/sup 11//cm/sup -3/ and magnetic field up to 80 gauss. A floating B dot probe, compensated to the capacitively coupled E field, was employed to measure the wave field in the plasma. It was observed that m=0 and n=1 mode and m=1 and n=2 mode helicon waves generated in the plasma using one turn loop and two turn loop antennas respectively. In case of using the modified Nagoya type antenna, m=1 and n=2 mode helicon wave was observed. The longitudinal wave number was proportional to the B/n, where n is plasma density. It was in fairly good agreement between the experimental results and the model considered the large aspect ratio (chamber radius over the chamber length). Furthermore, it was found that a transverse wave number of the m=1 mode. Helicon wave depended on the aspect ratio of the boundary plasma.