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CH3F/O2 inductively coupled plasmas at 10 mTorr were investigated using optical emission spectroscopy. A ‘self-actinometry’ method was developed to measure the absolute number density of CO that formed in reactions following dissociation of CH3F and O2 in the plasma. In this method, small amounts of CO were added to the plasma, leading to small increases in the CO emission intensity. By carefully accounting for small perturbations to the plasma electron density and/or electron energy distribution, and by showing that very little of the CO added to the plasma was decomposed by electron impact or other reactions, it was possible to derive absolute number densities for the CO content of the plasma. With equal fractions (0.50) of CH3F and O2 in the feed gas, the CO mole fraction as a function of plasma power saturated at a value of 0.20–0.25. As O2 in the feed gas was varied at a constant power of 100 W, the CO mole fraction went through a maximum of about 0.25 near an O2 feed gas fraction of 0.5. The relative CO number densities determined by ‘standard’ actinometry followed the same functional dependence as the absolute mole fractions determined by self-actinometry, aided by the fact that electron temperature did not change appreciably with power or feed gas composition. [ABSTRACT FROM AUTHOR]

The article discusses the papers included in the special issue of "IEEE Transactions on Plasma Science," devoted to atmospheric pressure plasma jets and their applications.

Plasma bullets have recently been used in novel applications in biology and medicine, which spurred interesting developments in the new interdisciplinary field of “Plasma Medicine.” In this paper, using high speed ICCD camera images we show that during their lifetime, plasma bullets undergo three distinctive phases: a launching phase during which the bullet velocity increases rapidly, a propagation phase during which the bullet velocity is temporarily maintained but later steadily decreases, and an ending phase during which the bullet collapses. [ABSTRACT FROM AUTHOR]

Measured relative densities as a function of O2 addition in a CH3F/O2 inductively coupled plasma changed abruptly for H, O, and particularly F atoms (factor of 4) at 48% O2. A corresponding transition was observed in electron density, effective electron temperature, and gas temperature, as well as in C, CF, and CH optical emission. These abrupt transitions were attributed to the reactor wall reactivity, changing from a polymer-coated surface to a polymer-free surface and vice-versa, as the O2 content in the feed gas crossed 48%. [ABSTRACT FROM AUTHOR]