Datensatz

Zusammenfassung

Using synchrotron radiation we simultaneously ionize and excite one helium atom of a helium dimer (He₂) in a shakeup process. The populated states of the dimer ion [i.e., He*⁺(n=2,3)-He] are found to deexcite via interatomic Coulombic decay. This leads to the emission of a second electron from the neutral site and a subsequent Coulomb explosion. In this Letter we present a measurement of the momenta of fragments that are created during this reaction. The electron energy distribution and the kinetic energy release of the two He⁺ ions show pronounced oscillations which we attribute to the structure of the vibrational wave function of the dimer ion.