Novel features in projectile x-rays and radiative electron capture photons emission from highly stripped channelled ions

Novel features have been observed in the projectile x-rays and radiative electron capture (REC) photons emitted from bare and H-like S ions of energy varying between 90 and 143 MeV and channelled along the direction in a Si single crystal. These features include enhancement of the photon yields along the channelled direction over that in a random case as well as their peaking close to . REC measurements have also been carried out for fully stripped and H-like oxygen ions at 84 MeV. All these results have been understood in terms of the electron capture and loss cross sections as well as the charge `freezing' of channelled ions.