Dynamic mechanisms of He single ionization by fast proton impact.

Abstract

Triple-differential ionization cross sections ${\mathit{d}}^{3}$\ensuremath{\sigma}/d${\mathrm{\ensuremath{\vartheta}}}_{\mathit{p}}$${\mathit{dcphi}}_{\mathit{p}}$${\mathit{dp}}_{\mathrm{rec}}$, the momentum distributions of singly charged recoil ions transverse to the beam direction as a function of the projectile polar (${\mathrm{\ensuremath{\vartheta}}}_{\mathit{p}}$), and azimuthal (${\mathit{cphi}}_{\mathit{p}}$) scattering angle were measured in order to elucidate the dynamics of 3-MeV ${\mathrm{H}}^{+}$ on He single ionization. For projectile polar deflections 0.2 \ensuremath{\le}${\mathrm{\ensuremath{\vartheta}}}_{\mathit{p}}$\ensuremath{\le}1 mrad and azimuthal scattering angles ${0}^{\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}$\ensuremath{\le}${\mathit{cphi}}_{\mathit{p}}$\ensuremath{\le}360\ifmmode^\circ\else\textdegree\fi{}, the kinematic regimes where two-body interactions dominate the three-body momentum exchange of the single-ionization reaction were separated experimentally.