Spin-orbit relaxation of Te(53P1) and Te(53P0)

Abstract

Spin-orbit relaxation of Te(5³P₁) and Te(5³P₀) by the gases H₂, D₂, O₂, He, Ar and Xe, has been studied using time resolved atomic absorption spectroscopy in the ultra-violet. The absolute rate for relaxation by H₂ was determined as k_H2=(1.03 ± 0.15)× 10^–11 cm³ molecule^–1 s^–1; cross-section σ_H2= 0.58 × 10^–16 cm². Relaxation by D₂ is three orders of magnitude less efficient than by H₂, and represents the largest quantifiable isotope effect known. The noble gases He, Ar and Xe were found to be relatively inefficient having cross-sections less than 10^–19 cm² for relaxation. Quenching by oxygen was also found to be inefficient (k_O2=(1.28 ± 0.55)× 10^–14 cm³ molecule^–1 s^–1; σ_O2= 2.6 × 10^–19 cm²). The results are discussed within the context of resonant energy transfer processes, and the role of predissociation of the potential energy surfaces is considered.