Optical diagnostic for examination of fast and thermal electrons from a helicon plasma source

Summary form only given, as follows. Helicon waves are excited in an argon plasma discharge by a twisted double helix antenna operating at 13.56 MHz. Two optical probes are used. One can be inserted into a I cm diameter glass tube in the center of the plasma chamber (about 11 cm diameter). The other observes the plasma from the outside. The optical probes are measuring emission from the short-lifetime At II states. Software is used to correlate the optical emission to the phase of the RF source. The Ar II emission is measured along with B-dot and Langmuir probe measurements at different axial positions. 105 GHz and 10 GHz; interferometry are used to verify Langmuir probe measurements. The result is to compare Ar II emission to B/sub z/ phase velocity and plasma density to determine the traveling wave particle and background Maxwellian interactions. The background level and modulation index of the Ar II emission is measured for this reason.