From a systematic analysis of the imaginary part of the alpha-nucleus phenomenological optical model potentials covering a large range of mass numbers and energies, it has been shown that the volume integral per target-projectile pair increases with increase of energy and saturates to a value in the neighborhood of 100 MeV ${\mathrm{fm}}^3$ at higher energies. Interestingly, this value is in remarkable agreement with those obtained using nucleons, deuterons, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, and t, as projectiles.

• Received 27 January 1984

DOI:https://doi.org/10.1103/PhysRevC.30.1760