Crossed Beam Collision Mechanics: Reactions of Ca, Sr, and Ba with HI and Limits on D° for CaI, SrI, and BaI

Abstract

Angular distributions of MI (M=Ca, Sr, or Ba) products scattered from crossed beams of HI and M are reported and compared with derived expressions for the angular distributions of the velocities of the center‐of‐mass. These comparisons indicate that the reaction threshold relative kinetic energies, E*, are 5, 4, and 2.5 kcal/mole for the Ca, Sr, and $\mathrm{Ba}+\mathrm{HI}$ reactions, respectively. Energy conservation and these measured E* values establish rigorous lower bounds for $D_0\mathrm{°(}\mathrm{MI})$ of 64 (CaI), 65 (SrI), and 66 (BaI) kcal/mole.