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arXiv · 1803.10841

Separating Dipole and Quadrupole Contributions to Single-Photon Double Ionization

S. Grundmann·F. Trinter·A. W. Bray·S. Eckart·J. Rist·G. Kastirke·D. Metz·S. Klumpp·J. Viefhaus·L. Ph. H. Schmidt·J. B. Williams·R. Dörner·T. Jahnke·M. S. Schöffler·A. S. Kheifets
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Abstract

We report on a kinematically complete measurement of double ionization of helium by a single 1100 eV circularly polarized photon. By exploiting dipole selection rules in the two-electron continuum state, we observed the angular emission pattern of electrons originating from a pure quadrupole transition. Our fully differential experimental data and companion ab initio nonperturbative theory show the separation of dipole and quadrupole contributions to photo-double-ionization and provide new insight into the nature of the quasifree mechanism.

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S. Grundmann, F. Trinter, A. W. Bray, S. Eckart, J. Rist, G. Kastirke, D. Metz, S. Klumpp, J. Viefhaus, L. Ph. H. Schmidt, J. B. Williams, R. Dörner, T. Jahnke, M. S. Schöffler, A. S. Kheifets. 2018-10-08. Separating Dipole and Quadrupole Contributions to Single-Photon Double Ionization. https://doi.org/10.1103/physrevlett.121.173003

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