Electron spectra from highly excited Si ions

Coster-Kronig electrons from the autoionizing Rydberg states of 2 MeV/u silicon projectiles excited through a thin carbon foil were observed at zero degrees. The most prominent lines came from Si10+ 1s22p(2P°1/2) nl-1s22sl' and 1s22p(2P°3/2) nl-1s22sl' transitions, with n ranging from 9 to ~20. Other peaks and shoulders in the spectra were examined.