Linear absorption measurements of pressure broadening in neon

Self-broadening of the neon lines lambda 585.2 nm and lambda 667.8 nm at 77 K and 300 K has been studied by the linear absorption technique using a tunable laser. The natural mixture of neon isotopes was excited in a weak DC discharge. The broadening is expected to be due mainly to the resonance interaction since the lower level of both lines is the strong resonance level 1s 2 . The radiation width of this level was derived from the Lorentzian widths of the lines extrapolated to zero density, leading to a resonance oscillator strength of 0.158(10). The measured broadening constants of lambda 585.2 nm and lambda 667.8 nm respectively were, in units of 10 23 MHz m 3 atom -1 , 77 K: 205(5), 204(9) and 300 K: 186(11), 191(6), where the quoted errors represent only statistical uncertainty. Pure resonance broadening would give the value 188(7). A slight curvature was detected in the broadening of both lines at the lower temperature.