Scattering, reactive rebound

Product PM has backward scattering with maximum very close to 180°, so that PM emerges from the reactive collision rebounding almost totally backwards from the direction in which P was originally moving. Likewise, N rebounds backward from the original direction of MN. 

Stripping, by its very nature, is a large impact parameter process. At small impact parameters the reactants collide head-on thus the Ar+ rebounds and is back scattered in the CM coordinate system either taking a D atom with it or not, depending upon whether the collision is reactive or nonreactive. Thus some back-scattered products are always expected, as is found experimentally (Fig. 8.8). 

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