Compound-nucleus effects on inner-shell ionization

If, in ion-atom collisions, only those events are experimentally selected in which the projectile nucleus strikes the target nucleus to form a compound-nuclear (CN) system, K-shell ionization may be affected during CN (i.e. united-atom, UA) formation and after CN formation. In the first case, if the K-shell is ionized on the way into the collision, a UA x-ray may be emitted during the CN life-time. In the second case, if the CN formation is resonant, the target K-ionization probability can fluctuate as the resonance is traversed. This paper discusses mainly the second case and shows that the theory of inner-shell ionization accompanied by CN formation, first developed by Blair, agrees with experiment over a wide range of experimentally chosen parameters. Once this has been assured, these concepts may be extended to studies of other nuclear delay time effects, e.g. in deep-inelastic or superheavy nuclear reactions, as discussed by Mueller and by Greenberg at this conference. 38 references, 6 figures, 1 table