66th Annual Gaseous Electronics Conference
Volume 58, Number 8
Monday–Friday, September 30–October 4 2013;
Princeton, New Jersey
Session UF1: Scientific Legacy of Arthur Phelps
1:30 PM–5:00 PM,
Friday, October 4, 2013
Room: Ballroom I
Chair: Bruce Wedding, University of South Australia
Abstract ID: BAPS.2013.GEC.UF1.2
Abstract: UF1.00002 : Personal Landmarks from the Legacy of Arthur Phelps
2:00 PM–2:30 PM
Preview Abstract
Abstract
Author:
John Lowke
(CSIRO Materials Science and Engineering)
I have been influenced for my whole life by Art Phelps, more than by anyone
else -- other than my wife! I first heard of Art Phelps in 1960 when, in the
middle of doing my PhD in Adelaide, South Australia, Frost and Phelps
published their land-mark paper, not only on drift velocities, the subject
of my PhD, but on Boltzmann analyses, which were to deliver detailed cross
sections for all common gases. Later I dared to suggest to my university
that one of my two external PhD examiners be Phelps, a move that led to me
being accepted for a position at Westinghouse Research Laboratories in
Pittsburgh for 6 years, with Phelps as my direct supervisor. Throughout this
period, Phelps refused to be a co-author of any of my papers, leaving me
with severe doubts as to what he thought of their quality! I list areas
where insights from Phelps inspired the growth of new fruit. (1) That
transverse and longitudinal electron diffusion coefficients differ,
typically by a factor of two. (2) That averaging radiation absorption
coefficients in electric arcs, using common weightings involving Black Body
radiation, can and usually do lead to errors of orders of magnitude. (3)
That CO$_{\mathrm{2}}$ laser discharges are largely controlled by electron
attachment rather than by diffusion or recombination. (4) That boundary
conditions for electrons at metal electrodes in arc welding, are not zero,
but from an astrophysical analogy, are zero when extrapolated to one mean
free path beyond the surface. (5) That the metastable vibrational states of
nitrogen become an energy gain rather than a loss process for low energy
electrons as occur in electrical breakdown in air, resulting in increases of
the ionisation coefficient by orders of magnitude. Coupled with the
detachment of electrons from negative ions by singlet delta states of
metastable oxygen molecules, sustaining discharge electric fields are
reduced a factor of five. Phelps worked on this problem with me until a few
months before he died.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2013.GEC.UF1.2