Integral recoil properties of 25 nuclides produced in the interaction of 800 MeV p${+}^{89}$Y were determined using activation techniques. The forward-to-backward recoil ratios are a factor of 3 larger for n-deficient products compared to near-stable and n-excess products of similar mass, a behavior not discovered in previous studies. The results are interpreted as an indication that the near-stable and n-excess products, previously assumed to be the result of conventional N-N intranuclear cascades, actually reflect a significant contribution from ‘‘target fragmentation’’ channels.

• Received 21 March 1988

DOI:https://doi.org/10.1103/PhysRevC.38.267