Knowledge Bank

Energy transfer form metastable Ar, produced in a flowing afterglow, to atomic Ca results in chemiluminescent chemiionization of Ca and chemiluminescent associative ionization, forming $CaAr+(A2\Pi )$. Inversion of the $A2\Pi \to X2\Sigma +$ spectrum of $BeAr+$ reported by Subbaram, $etal.,1$ yields potential functions which can $be2$ very accurately matched by a model potential of the form $V(R)=Aexp(-\beta R)-Z2e2\alpha /2R4$, where z is the effective charge of the alkaline earth ion. We have used this potential to analyze of the $CaAr+$ emission spectrum. These molecular ions exhibit bonding properties intermediate to chemically bound diatomics and to Van der Waals diatomics. An additional phenomenon, laser-assisted excitive Penning ionization, will be discussed whereby a laser field which is not resonant with either the products or the reactants of a collision but is resonant with the collision itself, can alter the product states.