Nuclear-excited Feshbach resonance in the Ar(P-3)+CH3Br Penning ionization reaction under orientation and velocity specified collisions

摘要

The collision-energy and orientation-angle-resolved Penning ionization cross section was determined for the Ar(P-3)+CH3Br reaction by using an oriented beam and a time-of-flight measurement. A remarkable resonance-type structure in the Penning ionization cross section is recognized in the collision energy dependence at fixed molecular orientations, which is very similar to the one we previously observed in the Ar(P-3)+CH3Cl reaction. This resonance-type structure could be interpreted as a new type nuclear-excited Feshbach resonance where the branching to competitive neutral dissociation channel is enhanced due to the formation of vibrationally excited CH3Br Rydberg states. (C) 2002 American Institute of Physics. [References: 25]