Charge transfer to continuum and high Rydberg states in proton-carbon-foil collisions

The authors investigate the n -3 scaling law for electron capture into high Rydberg states of fast protons. By extrapolating this electron capture process and the charge transfer to continuum states' process to the ionisation limit, a relationship is established that allows one to determine the exponent of the scaling law from the shape of the 'charge transfer to continuum states' peak. The asymmetry of this peak is also discussed. Data from proton-carbon-foil collisions give an average scaling law exponent of 2.95 for protons in the energy range 0.5-2.5 MeV.