Measurement of 10−1 s state-specific lifetimes in the neutral CO molecule

Abstract

Recently, a technique has been demonstrated which allows the measurement of metastable lifetimes in neutral molecules of up to ${10}^{\text{−3}} \mathrm{s}$ [J. Chem. Phys. 110, 6319 (1999)]. The present article extends the method by two orders-of-magnitude to molecular lifetimes as long as ${10}^{\text{−1}} \mathrm{s}.$ Using the CO metastable ${\mathrm{a }}^3\Pi$ state, lifetimes of eight rovibrational ${\mathrm{a }}^3\text{Π(v=3,Ω,J)}$ levels were measured. Within their experimental error of 30%, these lifetimes agree with previous theoretical predictions [J. Chem. Phys. 110, 6319 (1999)]. The presented technique is suggested for identification of molecular quintet states, in particular the CO $a^{″}{ }^5\Pi$ state.