Particle Charging in DC Corona Fields
After a brief review of the currently accepted theory of particle charging in corona fields in air by both ionic bombardment and diffusion in the dark space surrounding the dc corona glow, the paper presents some of the recently published findings on particle charging within the corona glow. The study was made possible by the discovery that additions of CO2 to air in a 5 to 20% range will increase a cylindrical positive corona glow to a size which is sufficiently large to allow particles to be dropped on to various trajectories parallel to the corona wire and their charge to be measured. The influence of the shape of the particles when exposed to corona charging is also discussed.
Electric Charging of Particles Near the Corona Glow Region in Air-CO2 Mixtures
Addition of 3 to 65 percent C02 to air results in the formation of an unusual glow around a positive corona wire and in a corresponding erratic charging of particles traversing this region. The results of the charging experiments for pellets shot in this glow region parallel to the corona wire are presented, as well as a possible explanation of the phenomenon. It is expected that the results will be of particular interest to the electrostatic precipitation and electrostatic painting industries.
Resonant Auger decay study of C1s -> pi* core-excited OCS
The present work aims at characterizing short-lived C1s((-1)) pi*((1)) core-excited states of the OCS molecule based on the analysis of the vibrational fine structure and lineshape profiles of the high-resolution resonant Auger decay spectra recorded at the excitation energies along the C1s -> pi* resonance in the binding energy region 15-19eV. Very different behavior in terms of lineshape and resonant enhancement is observed for the (A) over tilde, (B) over tilde and (C) over tilde final states. This is explained by (1) the variation in the C-O bond lengths for the states involved in the electronic relaxation and (2) different contributions in terms of Mulliken population to the molecular orbitals determining the electronic character of the corresponding states. Since the final-state geometries are known from a number of previous experiments and ab initio calculations, the geometry of the C1s((-1)) pi*((1)) intermediate states can be predicted in analogy with e.g. the N-2, CO2 and N2O molecules. (C) 2009 Elsevier B.V. All rights reserved. (Less)