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Absolute molecular-orbital thick-target x-ray yields have been measured for a wide variety of targets using 1.4-MeV/amu 5~ 5SNi, and S6Kr and 2.4-MeV/amu 84Kr beams. A scaling law for calculating two-collision molecular-orbital x-ray yields is derived which fits the shape of the measured yields very well in all collision systems examined, and the intensity within a factor of two for near symmetric ion-atom encounters.

Recently the measured proton-induced C K-shell ionization probability was found to vary significantly near the 0.461-MeV j = -+ elastic resonance in ' C. Since the resonance was so wide that time-delay effects on E-shell ionization should be very small, it was hypothesized that this effect was due to the exchange of angular momentum between the projectile motion and electron. Assuming a potential description of the nuclear scattering, we make a completely quantum-mechanical calculation of the ionization probability in the distorted-wave Born approximation and show that angular momentum effects do not account for these results. We also show how the amplitude for monopole excitation is augmented by the "shake-off" or "sticking" term found in the semiclassical theory of Ciocchetti and Molinari, and display the formal correspondence between the semiclassical and quantum-mechanical theories. Numerical calculations of the ionization probability show only a slight dip at the minimum in the p-C elastic cross section, opposite in sign and of much smaller magnitude than the reported variation.

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