Eur. Phys. J. D 5, 221-224 (1999)
https://doi.org/10.1007/s100530050248

Electron angular distributions in double photoionization: Use of effective Sommerfeld parameters

¹ Instituto de Astronomía y Física del Espacio, C.C. 67 - Suc. 28, 1428 Buenos Aires, Argentina
² Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-strasse 1, 85748 Garching, Germany
³ Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina

Received: 17 July 1998
Accepted: 23 October 1998
Published online: 15 February 1999

Abstract

We present calculations of the fivefold differential cross-section (FDCS) for double photoionization of helium at excess energies of 6 and 20 eV above threshold. Our results are obtained using for the final double-continuum state a product of three Coulomb wave functions, with the Sommerfeld parameters modified to describe the strength of interaction of any two particles affected by the third particle. Our calculations are compared with recent absolute measurements by Dörner et al. (Phys. Rev. A 57, 1074 (1998)), both in coplanar and non-coplanar geometries. Very good agreement is obtained for the shape of the angular distributions, and differences in the absolute magnitude exist in comparison with the standard choice of Sommerfeld parameters.