The angular distributions of the P1, P3, and P2 lines of 2-MeV/amu Mg projectiles excited by collision with carbon and aluminum atoms in thin foils have been measured with a pivoted plane-crystal Bragg spectrometer. Both the polarizations of these lines and the reflection properties of the ammonium dihydrogen phosphate (ADP) diffraction crystal have been determined. The 0/1 cross-section ratios for populating the 2p(m=0) and 2p(m=1) states in the 1s2p He-like and the 2p H-like configurations were deduced from the polarization values and compared with the coupled-states calculation of Reading et al., assuming that the mechanism populating these states is the capture of electrons from the K shell of the target. The agreement between theory and experiment is very good for carbon excitation, but for aluminum excitation the theory significantly overestimates the cross-section ratio. The influence of foil tilting and cascade contributions on the polarization were investigated experimentally and taken into account in the analysis of the measurements.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics