A laser produced plasma sustained by a radiofrequency source

Summary form only given. The creation of a high-density plasma in a high pressure environment is studied. The plasma is generated by photoionization of the organic seed molecule tetrakis(dimethylamino)ethylene (TMAE) and is sustained by RF coupling through the use of an antenna. The coupled power is a function of antenna configuration, plasma density, working gas and applied magnetic field. Previous studies have utilized these antennas to couple power to the plasma through the inductive mode of operation. The inductive source operates by coupling power to the plasma through collisional ohmic heating of the wave energy. Helicon antennas have been shown to be very efficient sources in the low pressure argon regime with densities of the order of 4/spl times/10/sup 12/ cm/sup -3/ with only 600 W of power in a 5 cm radius tube. The VUV laser in this experiment has created plasmas of order 10/sup 14/ cm/sup -3/. The high density gives a high condition which allows higher radiation resistance of the antenna and more power to couple the plasmas. The use of different working gasses is explored and the results are compared and interpreted. The computer codes, ANTENNA2 and MAXEB are used to optimize the experiment and interpret results. The radiation resistance is measured using a network analyzer, and compared to code results. The plasma parameters are measured by Langmuir probes and optical emission spectra.