Using an improved actinometry method, additive nitrogen effects on oxygen plasma downstream ashing have been studied. The ion current of the Langmuir probe and emission intensity change in OI(7774) and OI(8446) as a function of nitrogen mixing ratio showed that emission caused by dissociative excitation of oxygen molecules did not significantly influence the actinometry in our experiment. Thus, the actinometry measured accurate relative concentrations of atomic oxygen in the plasma by selecting XeI(4671) or XeI(4624) for the actinometer to OI(7774) and OI(8446) or by using ArI(7503) or ArI(7067) for the actinometer to OI(6258) and OI(4368). The change in the ashing rate and the relative concentration of atomic oxygen as a function of the nitrogen mixing ratio corresponded well, and both values at 10% nitrogen mixing were twice those with no nitrogen mixing. The activation energy was unchanged regardless of additive nitrogen. Therefore the role of nitrogen as the additive impurity gas is only to increase oxygen in the plasma.

We present some characteristics of the observables A , and A,o of the pp-*nd reaction deduced from the world-available data, Emphasis is given to their extrema and to their trajectories as a function of the centre-of-mass (CM) angle.

Ashing properties in a surface-wave mode at 133 Pa and 1 kW with an alumina disk-plate window are investigated by comparison of those in a volume mode with a quartz disk-plate window. In the surface-wave mode, plasma is confined to the alumina window surface area and ashing in a downstream area is carried out mainly by atomic oxygen. The ashing activation energy of 0.42 eV in the surface-wave mode ashing is comparable to 0.5 eV with an ashing condition by atomic oxygen at the ground state [O(3P)](the so-called downstream state). These results indicate that the plasma in the surface-wave mode can realize a downstream ashing condition. On the other hand, ashing with a quartz window was done by plasma, where the activation energy is influenced by built-in high-frequency magnetic field. Moreover, the ashing rate distribution in the surface-wave mode characterized with the alumina window is more uniform than that in the volume mode with the quartz window.

We report a detailed quantum oscillation study of the overdoped cuprate Tl 2 Ba 2 CuO 6+δ at two different doping levels (T c = 10 and 26 K). The derived Fermi surface size and topology complement earlier angle-dependent magnetoresistance studies and confirm the existence of a large quasi-cylindrical hole-doped Fermi surface with a small, but finite, c-axis warping. An accurate determination of the hole concentration reveals that superconductivity in Tl 2 Ba 2 CuO 6+δ does not follow the universal T c ( p) parabola for cuprate families and survives up to a larger doping of p c = 0.31. The observation of quantum oscillations for both dopings demonstrates that Fermi liquid behaviour is not confined to the edge of the superconducting dome, but is robust up to at least 0.3T max c . Moreover, the observation of such well-resolved oscillations implies that the physical properties of overdoped Tl 2 Ba 2 CuO 6+δ are determined by a single, spatially homogeneous electronic ground state. Finally, analysis of the different quasiparticle masses points towards a purely magnetic or electronic pairing mechanism.