Evidence for Fermi-shuttle ionization in intermediate velocity C+ + Xe collisions

Area of Science:

• Atomic and Molecular Physics
• Collision Physics
• Quantum Mechanics

Background:

• Understanding electron emission in ion-atom collisions is crucial for atomic physics.
• Previous studies focused on single ionization events, leaving multiple scattering phenomena less explored.

Purpose of the Study:

• To experimentally investigate and identify multiple electron scattering (ping-pong) events in ion-atom collisions.
• To analyze the contribution of these multiple scattering events to electron spectra.

Main Methods:

• Utilizing single C+ +Xe collisions at specific impact energies (150 and 233 keV/u).
• Analyzing the high-energy portion (300-3400 eV) of double differential electron spectra.
• Employing reference measurements with He+ projectile ions and theoretical calculations for identification.

Main Results:

• Experimental evidence for consecutive projectile-target-projectile (triple) and projectile-target-projectile-target (quadruple) electron scattering was obtained.
• Distinct signatures of multiple electron scattering were identified in the electron spectra.
• These signatures were successfully separated and attributed to the observed scattering processes.

Conclusions:

• The study provides the first experimental evidence for triple and quadruple electron scattering in C+ +Xe collisions.
• The findings clarify the complex electron emission mechanisms in ion-atom interactions.
• This research contributes to a deeper understanding of electron dynamics in atomic collisions.