Argon and air mixture plasmas produced by a radiofrequency plasma source

Summary form only given. A radiofrequency helicon plasma source is used to study the creation and sustainment of a high density plasma of air constituents (N/sub 2/, Ar and O/sub 2/). Various antenna configurations including helical antennas are used in conjunction with with a capacitive matchbox system and a broad-band (2-200 MHz) high power (1 kW) amplifier to couple power to the plasma. A calibrated Bird meter at the matchbox allows for real time monitoring and measurements of forward and reflected power. The role of antenna configuration, applied magnetic field (100-1400 G) operating frequency and gas concentrations of the power coupled to the high-density (10/sup 11/-10/sup 13/ cm/sup -1/) plasma have previously been examined at lower gas pressure (10-100 mTorr) and these results will be extended to higher pressure regimes. Experiments at lower pressures (10-100 mTorr) with a working gas of argon exhibit an intense 4 cm diameter blue mode emission, indicative of the excitation of the Argon II state. This blue core emission will be further studied with the use of photomultiplier tube and spectrometer.