Properties of metastable krypton atoms in afterglows produced in krypton and krypton–nitrogen mixtures

Abstract

Light absorption techniques are used to study the temporal dependence of the number densities of the 5s′₀₀ and 5s₁₂ krypton metastable atoms during the decay period (afterglow) of a pulsed discharge in krypton and krypton–nitrogen mixtures. The sensitivity of the temporal properties of the 5s′₀₀ state of krypton to discharge pulse conditions was attributed to an electron destruction process. The 5s₁₂ state was not affected by discharge excitation conditions, permitting the measurement of the diffusion coefficient (Dp₀=29.3 cm² sec⁻¹ Torr) and of the two‐body and three‐body reaction rate constants in pure krypton (k₁=2.44×10⁻¹⁵ cm³ sec⁻¹ and k₂=2.59×10⁻³² cm⁶ sec⁻¹, respectively). In krypton–nitrogen mixtures the additional loss of the 5s₁₂ state of krypton due to its reaction with nitrogen was determined to have a reaction rate constant of 3.33×10⁻¹² cm³ sec⁻¹. Light emission studies made using a flowing afterglow system show that this process populated a wide range of vibrational levels of the B ³Π_g state of the nitrogen molecule.