Experimental derivation of Arrhenius equations for collisional quenching rate coefficients of Ar(³P₂) by Ar(¹S₀) and H₂O

This paper presents the temperature dependence for the collisional quenching rate coefficient of the metastable excited atom Ar(³P₂) by the water molecule H₂O. A few papers reported on the collisional quenching rate coefficients of the metastable excited atom Ar(³P₂) by the ground state atom Ar(¹S₀) and the water vapor molecule (H₂O) have already been published; however, their temperature dependences have not been reported. We determined them experimentally by a nonspectroscopic method following our previous works on the metastables Ne(³P₂) and . The effective lifetime of Ar(³P₂) was measured in Ar and Ar/H₂O mixtures in a Townsend discharge by a pulsed afterglow technique. The collisional quenching rate coefficients of the metastable excited atom Ar(³P₂) by Ar(¹S₀) and H₂O were determined as 1.22  ×  10⁻¹⁵ and 2.31  ×  10⁻¹⁰ cm³ s⁻¹ at 300 K, respectively. The diffusion coefficient and reflection coefficient of Ar(³P₂) at a cathode surface were also determined. Furthermore, the temperature dependences of both the collisional quenching rate coefficients were investigated and expressed as Arrhenius equations. The data are expected to enable the numerical simulation of the reaction between H₂O and the metastable excited atoms produced by dielectric barrier discharges and atmospheric plasma jets in air plasma. (paper)