Integral frequency distribution of projectile alpha fragments in nuclear multifragmentations at intermediate and high energies

The integral frequency distributions of the numbers of projectile alpha fragments produced in nuclear multifragmentations at intermediate and high energies are studied by a simple two-source model. The calculated results are approximately in agreement with the experimental data of 16O, 40Ar, 56Fe, 84Kr, 139La, and 197Au multifragmentations in nuclear emulsions at 2.00A, 1.80A, 1.80A, 0.08–1.70A, 0.60–0.99A, and 0.60–0.99A GeV, respectively. The initial energy of nuclear limiting fragmentation is expected to be at or lower than 0.08A GeV. Two correlations between the mean multiplicity of projectile alpha fragments (〈nα〉) and the projectile mass number, as well as 〈nα〉 and the maximum multiplicity of projectile alpha fragments are observed.