Determination of the relaxation constant of the $3s_2-3p_4$ transition in neon by investigation of the absorption line wings

A tunable Zeeman laser $(\lambda=3,39\mu m)$ was used to determine the dependences of the relaxation constant of the $3s_2-3p_4$ transition in neon on the pressure in $He^3:Ne^{20}=5:1$ mixture and in pure $Ne^{20}$. These measurements were made in the wings of the absorption line corresponding to this transition (the tuning range of an $He-Ne$ probe laser was $\pm3$ GHz) using a modulation method for the determination of the absorption coefficient. Within the limits of the experimental error, the dependences obtained were linear and the slopes were $59\pm6$ MHz/Torr for the helium-neon mixture and $32\pm2$ MHz/Torr for the pure $Ne^{20}$ isotope.