CRD and LIF spectra of the CaBr and CaI radicals

The CRDS technique has been used to record CaBr and CaI absorption spectra at temperatures (about 350 K) much lower than the spectra observed previously with the traditional techniques (T = 1300–2000 K). For the CaBr A2Π–X2Σ+ transition, the bandhead intensity distributions of the CRD and LIF spectra are similar. In contrast, one observes a significant intensity weakening of the C2Π3/2–X2Σ+ heads in the LIF spectrum of CaI. This is further manifestation of a spin–orbit selective pre-dissociation of the Ω = 3/2 component of the C2Π state, confirming the recent observation of its anomalously short lifetime.