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Updated: Jun 12, 2026
06:53
Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
Single photon double ionization of the helium dimer
T Havermeier1, T Jahnke, K Kreidi
1Institut für Kernphysik, J. W. Goethe Universität, Max-von-Laue-Strasse 1, 60438 Frankfurt, Germany.
Physical Review Letters
|May 21, 2010
Summary
A single photon can ionize both helium atoms in a helium dimer up to 10 angstroms. This double ionization process, observed via Coulomb explosion imaging, reveals the helium dimer
Area of Science:
- Atomic and Molecular Physics
- Quantum Chemistry
- Chemical Physics
Background:
- Helium dimer (He2) is a weakly bound van der Waals molecule.
- Understanding molecular ionization dynamics is crucial for various fields.
Purpose of the Study:
- To investigate the double ionization mechanism of the helium dimer induced by a single photon.
- To characterize the energy sharing and angular distributions of ejected electrons and ions.
Main Methods:
- Single photon ionization experiments.
- Coulomb explosion imaging (CEI).
- Analysis of electron and ion momentum distributions.
Main Results:
- Demonstrated single-photon double ionization of He2 up to 10 angstroms.
- Identified a knockoff mechanism for double ionization, supported by energy sharing and angular distributions.
- Obtained direct visualization of the He2 nuclear wave function.
Conclusions:
- Single photons can efficiently induce double ionization in the helium dimer.
- The knockoff mechanism plays a significant role in this process.
- Coulomb explosion imaging provides unprecedented insight into the structure of weakly bound molecules like He2.
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