Energy dependence of the 6Li(α,2α)pn reaction from 77 to 119 MeV

Four-body 6Li(α,2α)pn breakup cross sections were measured from 77 to 119 MeV. Spectral functions S for k=0.1 fm-1 (where ℎk is the p-n relative momentum) were deduced. Those obtained from the 89 to 119 MeV data are internally consistent, and agree with the k dependence of S found in earlier studies of the (α,2α)pn and (p,pα)pn reactions on 6Li. However, the S found at 77 MeV was low, which may indicate distortion effects. Throughout this energy region, the four-body breakup cross section at low p-n excitation follows the α-α elastic scattering cross section as the latter changes by a factor of 50, showing that quasifree scattering is the dominant process