Electrons ejected with half the projectile velocity and the saddle point mechanism in ion-atom collisions

The role of the potential saddle in He2+ + H impact ionization

We compute the full three-dimensional momentum space distribution of ejected electrons resulting from alpha particle impact ionization of hydrogen. At low impact velocities the transverse momentum distributions are shown to exhibit strong oscillations with energy. For the longitudinal component, the momentum distribution peaks near the target at high energies, shifts towards the projectile cent...

Dynamics of electron-capture-to-continuum (ECC) formation in slow ion–atom collisions

The zero-degree ejected-electron spectrum for protons incident on He at 25 keV is examined experimentally using the COLTRIMS technique. The momentum distribution of the emitted electrons for the transfer ionization (TI) reaction channel is measured in coincidence with the momentum vectors of the recoil ion and the scattered projectile. The momentum distribution of the electrons emitted around z...

Single ionization of He by low-velocity protons and C6+: Ejected electron momentum distributions.

A technique for electron spectroscopy which yields full two-dimensional momentum distributions for continuum electrons has been used to study ejected electrons from single ionization of He by C and proton projectiles at low velocities. Projectile velocities of 1.63, 1.38, and 1.16 a.u. for C and 2.39, 1.71, 1.15, .85, and 0.63 a.u. for protons were used. All spectra show much broader distributi...

Saddle-point electrons in ionizing ion-atom collisions.

X-ray production by ion bombardment

2014 The available experimental and theoretical results on ion induced X-rays are briefly surveyed. From experimental data it may be concluded that the mechanism for inner shell excitation by heavy ion-atom collisions is different from that for proton-atom collisions. The latter are described successfully in Plane Wave Born Approximation (PWBA) and in classical Binary Encounter Approximation (B...