Broadening of a Two-Photon Resonance in a Zinc Atom in Collisions with CO_2 , CO, and NO Molecules

摘要

The broadening of a two-photon resonance is studied experimentally at the 4s ~1S_0–6s~3S_1 transition in a zinc atom upon absorption of two waves with a small detuning from an intermediate state in collisions with CO_2 , CO, and NO molecules. The measured absolute values of broadening cross sections greatly exceed gas-kinetic cross sections and are (9.4 ± 2.4, 6.5 ± 1.6, and 3.9 ± 1.0) * 10~(-14) cm~2 for CO_2 , CO, and NO, respectively. Anomalously large rate constants and cross sections obtained in experiments are explained by the efficient resonance quenching of the excited states of zinc atoms in collisions with molecules accompanied by transfer of the energy of excited atoms to vibrational-rotational degrees of freedom of molecules.