X-ray production by channeled ions

RBS and X-ray spectra have been measured for random and aligned (parallel to 〈100〉 axis) orientation of Si crystals and SOS (silicon on sapphire) crystals of 4000 Å thick Si. The projectile energy has been changed over the ranges 0.5–2.0 MeV for protons and 0.25–0.6 MeV/amu for α particles. The ratio of X-ray counts of the aligned case to those of the random case is shown as a function of projectile energy separately for Si K X-rays and continuum bremsstrahlung. The impact-parameter dependence of ion-atom collisions for producing these X-rays is discussed.