STUDY OF THE STRUCTURE OF RADIO-FREQUENCY GLOW-DISCHARGES IN CH4 AND H-2 BY SPATIOTEMPORAL OPTICAL-EMISSION SPECTROSCOPY

Radio frequency discharges at 13.56 MHz in CH4(100%), CH4(10%)/H-2, and H-2(100%) are investigated by time- and space-resolved optical emission spectroscopy. The spatiotemporal net-excitation profile of H(n = 3) is presented and discussed. The absolute value of the net-excitation rate, the emission intensity, and the density of the optically allowed electronic excited species are also measured. The self-quenching rate of H(n = 3) and CH (A) by H-2 and CH4 are estimated and compared with the previous works. The importance of the quenching of CH (A) by atomic hydrogen is also discussed. Excitation by very high-energy electrons is shown from the difference of the emission profile between H(alpha) and H-2(d(3)PI(u) --> a(3)SIGMA(g)+) in H-2 at 100 kHz.