Crossed molecular beams kinetics: BaO recoil velocity spectra from Ba+N2O

Abstract

Laboratory (LAB) angular and time-of-flight (TOF) recoil velocity spectra of BaO product produced by crossing a thermal Ba beam with an N2O nozzle beam have been measured in a molecular beam apparatus equipped with an electron bombardment ionizer–quadrupole mass filter ’’universal’’ detector. Product center-of-mass (c.m.) recoil angle and energy distributions have been fit to the data by convoluting the c.m.→LAB transformation over the measured speed distributions of both beams and the bandpass of the TOF analyzer for different N2O vibration and relative collision energies. The results indicate a direct reaction mechanism with substantial internal excitation of the products. Backward scattering of the BaO relative to the initial Ba direction is favored, but the product angular distribution also broadens as the reactant energy increases.