Berlin 2001 – wissenschaftliches Programm

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AMPD: EPS AMPD

AMPD 1: Sitzung 1

AMPD 1.4: Vortrag

Montag, 2. April 2001, 15:00–15:25, H105

Non-dipoleEffects in Spin Polarization of Photoelectrons from Xe 4p and 5p Shells — •Nikolai Cherepkov and Sergey Semenov — State University of Aerospace Instrumentation, 190000 St. Petersburg, Russia

The contribution of electric-dipole - electric-quadrupole interference terms to the spin polarization of photoelectrons ejected from atomic np-shells is analysed theoretically. The numerical calculations in the non-relativistic random phase approximation with exchange for Xe 4p- and 5p-shells show that even at low photon energies (below 350 eV) this contribution is not negligibly small. For 4p-shell it can reach 15 change completely the shapes of the angular dependencies of the degree of electron polarization in the photon energy region where the spin polarization parameters in the electric- dipole approximation are approaching zero values. Possible experimental geometries are proposed which allow an easy observation of these effects. That kind of measurements give an additional information on the electric-quadrupole terms as compared to the information obtained earlier from the angular distribution measurement without spin analysis, and in principle can allow to extract the quadrupole matrix elements and phase shift differences directly from the experimental data, that is to perform a complete experiment in this approximation.