An angular method of identifying diffractive excitation (DE) events for interactions of a hadron beam in nuclear emulsion is applied to identifying DE events in interactions of heavy ions beams. The ‘‘apparent’’ mean free paths (MFP) of DE processes for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ${(}^{28}$Si) beams are 1.00±0.12, 2.$4_{\mathrm{-}0.7}^{+1.6\mathrm{}}$, and 2.2±0.4 (1.5±0.2) m, respectively, at 200, 60, and 14.6 GeV/nucleon, which corresponds to 20–10% of the MFP for total inelastic interactions. Distinctive features of diffractively excited nuclei are discussed.

• Received 21 May 1990

DOI:https://doi.org/10.1103/PhysRevC.43.1410