Atomic charge exchange between semi-relativistic ( v/c = 0.49 ) helium ions and targets from carbon to lead.

Abstract

In ( 3 He,t) nuclear charge-exchange reactions, 3 He + charge states are produced as a result of atomic charge-exchange between 3 He ++ ions and atoms in the target. In equilibrium, the atomic charge-exchange process consists of both electron ionization (stripping), and electron capture, which can proceed through Radiative Electron Capture (REC) or Non-Radiative Electron Capture (NREC). Unfortunately, a complete description of the atomic charge-exchange process is lacking. As a result, a largely phenomenological approach has been used, which has not been tested for high beam energies. In this work, ratios of equilibrium charge-state yields for singly to doubly ionized 3 He ions were measured using the Grand Raiden Spectrometer at the Research Center for Nuclear Physics (RCNP). A semi-phenomenological approach used when calculating atomic electron capture and stripping cross sections is successful in describing the data for beam energies of E( 3 He) = 420 MeV. 10th Symposium on Nuclei in the Cosmos

Theoretical Interpretation of Atomic Charge Exchange between Singly Charged Helium Ions and Aluminum Foils

“…The charge-state distribution is governed by electron capture and loss processes occurring when ions pass through the Al-foil Meharchand et al, 2007). It was found that the charge-state fractions depend on the magnitude of the cross sections for electron-capture σ c and electron-loss σ L of the ions in various charge-states.…”