Production of fast fragments by bombarding light nuclei with intermediate-energy protons

The high-energy parts of the spectra of ³H, ³He and ⁴He nuclei obtained in bombarding Li, Be and C targets with 665 MeV protons as well as the spectra of fast deuterons as a function of the proton energy (from 380 to 665 MeV) at a lab angle of 5.5° have been measured. The mechanisms of the interactions of intermediate-energy protons with light nuclei are discussed. It is found that the production of fast nuclear fragments at a small angle can be explained to a large extent by direct nuclear reactions of two types, i.e. quasielastic scattering and pion production processes on clusters.