AVS 50th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeA

Paper PS2-WeA2
Measurement of the Fluorine Atom Concentration in a Carbon Tetrafluoride and Helium Atmospheric-Pressure Plasma

Wednesday, November 5, 2003, 2:20 pm, Room 315

Session: Atmospheric Plasmas & Micro Discharges
Presenter: X. Yang, University of California, Los Angeles
Authors: X. Yang, University of California, Los Angeles
S.E. Babayan, University of California, Los Angeles
G.R. Nowling, University of California, Los Angeles
M. Moravej, University of California, Los Angeles
R.F. Hicks, University of California, Los Angeles
Correspondent: Click to Email
A titration technique has been developed to measure the fluorine atom concentration in the downstream region of a low-temperature, atmospheric pressure plasma fed with helium and carbon tetrafluoride. The fluorine atoms were titrated with H@sub 2@ molecules, and the HF reaction product was detected by infrared spectroscopy. The radio-frequency gas discharge produced 1.2x10@super 15@ cm@super -3@ of F atoms, which was about two orders of magnitude higher than that found in low-pressure plasmas. The average electron density and temperature in the plasma was estimated to be 6.1x10@super 11@ cm@super -3@ and 2.5 eV. A numerical model of the plasma indicated that most of the fluorine atoms were generated by the reaction of CF@sub 4@ with metastable helium atoms. The results of the experiments and the model will be presented at the meeting.