https://doi.org/10.1007/s100530050357
Electron excitation of neutral and ionic levels in Townsend discharges of argon at high E/N
1
Institute of Physics, P.O.B. 57, 11001 Belgrade, Yugoslavia
2
Faculty of Physics, University of Belgrade, P.O.Box 550, 11001 Belgrade,
Yugoslavia
Received:
18
January
1999
Revised:
12
April
1999
Published online: 15 August 1999
We have measured the emission coefficients of the 3p levels of ArI: 
,
, 
, 
, 
, and 
. The data for the , , , and
levels were converted to excitation coefficients by using quenching coefficients
from the literature. Measurements were performed in the range of E/N between
to above 
except for the level
where measurements were done only up to 
. The data for the
emission coefficients for Ar II levels include two 4p' levels with terms 
and
, and three 4p levels with terms , 
and
. The measurements for the ionic levels were done for E/N above 
up to nearly 
. The absolute values of the
coefficients were obtained from the intensity of the light emitted at the anode in the
parallel plate self-sustained Townsend argon discharges. For low E/N the apparent emission
coefficients (i.e. the normalized spatial profile of emission) for both neutral and ionic
levels increase exponentially in almost the entire discharge gap. At about 
the exponentially increasing signal was obtained only near the anode, while
at 
the spatial dependence was flat throughout the electrode
gap.
PACS: 52.20.Fs – Electron collisions / 52.25.Rv – Emission, absorption, and scattering of visible and infrared radiation / 52.80.Dy – Low-field and Townsend discharges
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999
