Send to

Choose Destination
See comment in PubMed Commons below
Phys Rev Lett. 2013 Jul 5;111(1):013003. Epub 2013 Jul 2.

Ejection of quasi-free-electron pairs from the helium-atom ground state by single-photon absorption.

Author information

Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.


We investigate the single-photon double ionization of helium at photon energies of 440 and 800 eV. We observe doubly charged ions with close to zero momentum corresponding to electrons emitted back to back with equal energy. These slow ions are the unique fingerprint of an elusive quasifree photon double ionization mechanism predicted by Amusia et al. nearly four decades ago [J. Phys. B 8, 1248 (1975)]. It results from the nondipole part of the electromagnetic interaction. Our experimental data are supported by calculations performed using the convergent close-coupling and time-dependent close-coupling methods.

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Physical Society
    Loading ...
    Support Center