High-resolution photoelectron satellite spectrum of He excited by synchrotron radiation at 96.5 eV photon energy

Abstract
The photoelectron spectrum of He has been measured, with very high resolution, using synchrotron radiation at 96.5 eV photon energy. The final Rydberg states in the satellite spectrum can be followed up to n=11. The relative intensities have been determined and it is found that the intensities very accurately follow the n-3 dependence for the higher Rydberg states. Also the intensity (per eV) of the shakeoff continuum near to the threshold, relative to the main 1s single-ionization channel has been measured to be 0.20(2)% of the main 1s peak per eV.