Absolute charge transfer and fragmentation cross sections in He2+-C60 collisions
A Rentenier1, L F Ruiz, S Díaz-Tendero
1Laboratoire de Collisions, Agrégats et Reactivité, UMR 5589 CNRS, Université Paul Sabatier 3, 31062 Toulouse, France.
Physical Review Letters
|June 4, 2008
Summary
We studied He2++C60 collisions, finding electron transfer and fragmentation processes are complex. Transfer-ionization is key at low energies, while multifragmentation dominates at higher energies.
Area of Science:
- Atomic and Molecular Physics
- Chemical Physics
- Plasma Physics
Background:
- Understanding ion-molecule collisions is crucial for plasma physics and astrophysics.
- Fullerenes (C60) exhibit unique fragmentation dynamics under energetic ion impact.
Purpose of the Study:
- To determine absolute charge transfer and fragmentation cross sections for He2++C60 collisions.
- To elucidate the underlying mechanisms of electron capture and fragmentation in these collisions.
Main Methods:
- Combined experimental measurements and theoretical calculations.
- Analysis of charge transfer and fragmentation patterns across a wide impact energy range (0.1-250 keV).
Main Results:
- Cross sections for He+ and He0 formation are comparable, indicating significant transfer-ionization.
- Transfer-ionization processes are important even at low impact energies.
- Multifragmentation dominates above 40 keV, while sequential C2 evaporation prevails at lower energies.
Conclusions:
- The dynamics of He2++C60 collisions involve a complex interplay of electron capture and ionization.
- Transfer-ionization plays a critical role across the studied energy spectrum.
- Collision energy dictates the dominant fragmentation pathway of the C60 molecule.
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