Reactive Content of the First-Order Optical Potential

It is shown that the total reaction cross section appropriate to the optical potential for scattering of a projectile by a target of uncorrelated particles (nucleons) can be written to a good approximation as a sum of exclusive cross sections for $n$-nucleon knockout. The association made by some authors of the reactive content of this optical potential with single-nucleon knockout is shown to apply to the inclusive-reaction cross section only.