Pressure broadening of Ar and Kr (n+1)s[3/2]2→(n+1)p[5/2]3 transition in the parent gases and in He

Abstract

Tunable diode laser spectroscopy technique was employed to determine pressure broadening coefficients for the (n+1)s[3/2]2→(n+1)p[5/2]3 transitions in Ar and Kr in RF discharge plasma. The widths of Gaussian and Lorentian components of the absorption lines were determined simultaneously by fitting absorption line profiles obtained in experiments to a Voigt profile. The technique was validated in measurements of pressure broadening coefficient for 811.5nm Ar absorption line in the pressure range of 15–75Torr. The obtained values for these coefficients reduced to 300K are ξAr–Ar=(2.8±0.1)×10−10s−1cm3 for broadening in the parent gas and ξAr-He=(3.2±0.2)×10−10s−1cm3 in helium.For krypton, isotope abundance was accounted for and appropriate fit function was constructed permitting to determine pressure broadening coefficients using the natural mixture of isotopes. For krypton 811.3nm line these coefficients are ξKr-Kr=(2.4±0.2)×10−10s−1cm3 and ξKr-He=(3.1±0.2)×10−10s−1cm3.