A. Bielski et al., Experimental study of speed-dependent collisional effects of He and Ne on the 687.1 nm argon line, EUR PHY J D, 8(2), 2000, pp. 177-187
Using a pressure-scanned Fabry-Perot interferometer precise measurements of
the profiles of the 687.1 nm argon line perturbed by helium and neon press
ures between 0.5 and 44 torr have been performed. Careful analysis of line
shapes showed that for Ar-He the speed-dependent effects do not play any es
sential role. Contrary to that, for Ar-Ne these effects can give rise to no
ticeable decrease of the Doppler width determined using the Voigt profile.
It was shown that for Ar-Ne the inclusion of speed-dependent effects can re
duce the apparent dependence of the Doppler width on the neon density and c
ause the Doppler temperatures determined from the profiles to be consistent
with the source temperature. The role of the Dicke narrowing is also discu
ssed.