Change in total angular momentum within the z°3titanium excited state induced by collisions with ground-state argon, neon, and helium atoms

Collisions that produce a change in the total angular momentum and quenching processes involving the triplet z ${}_{}{}^3{}_{}{}^{}°$ titanium excited level and noble gases have been studied by laser perturbation and time-resolved spectroscopy. Titanium atoms are produced in a hollow-cathode discharge, and the analysis of resonance and sensitized fluorescence light decays enable us to determine total-angular-momentum-changing (J-changing) and quenching cross sections induced by collisions with helium, neon, and argon atoms. The thermally averaged J-changing cross section (z ${}_{}{}^3{}_{}{}^{}F$ °${\mathrm{}}_i$→z ${}_{}{}^3{}_{}{}^{}F$ °${\mathrm{}}_j$) in units of ${10}^{\mathrm{-}16}$ ${\mathrm{cm}}^2$ are σ${¯}_{4\to 2}$=1.7±0.5, 0.7±0.06, 3.1±1; σ${¯}_{4\to 3}$=11±2, 1.4±0.1, 11±1; σ${¯}_{3\to 2}$=7±2, 2.2±0.3, 14±2, respectively, for helium, neon, and argon colliding partners. As for alkali-metal–noble-gas collisions, a pronounced minimum of the J-changing cross sections is obtained for the titanium (z ${}_{}{}^3{}_{}{}^{}F$ °)–neon collisions. Radiative destruction probabilities of the z ${}_{}{}^3{}_{}{}^{}F$ °${\mathrm{}}_j$ (j=4,3,2) titanium sublevels have been measured also, and good agreement with accepted values is found.