Level Crossing and Double Resonance on the A 1π State of CS

Using the coincident atomic spectral line MnII 2576.1 to pump the $\text{R(7)}$ transition of the 0–0 band, level crossing and double resonance are observed in the ${}^1\Pi$ state of carbon monosulfide. From the Hanle effect a lifetime value of 2.0 ± 0.4 × 10⁻⁷ sec is obtained. The analogous Stark level crossing effect and the Stark–Zeeman recrossing effect give estimates of the dipole moment μ and lambda doubling δ. With an rf search aided by these estimates, optical‐rf double resonance provides more accurate values: ${\mu }_8\text{\hspace{0.17em}=\hspace{0.17em}0.68\hspace{0.17em}±\hspace{0.17em}0.01}\mathrm{D}$ ; ${\delta }_8\text{\hspace{0.17em}=\hspace{0.17em}1099.4\hspace{0.17em}±\hspace{0.17em}0.3}\mathrm{MHz}$ for the $\text{J\hspace{0.17em}=\hspace{0.17em}8}$ level. Considering the effect of nearby perturbing states, it is estimated that ${\mu }_{\Pi }{\mathrm{\hspace{0.17em}=\hspace{0.17em}\mu }}_8\text{\hspace{0.17em}±\hspace{0.17em}0.08}\mathrm{D}$ . A derivation of signal intensity for the double resonance experiment is used to obtain the rf power requirements and criteria for selecting the optimum polarization.