Spectral shape of the 2E1 decay from 2s state in He-like tin

Ajay Kumar (1) , Sergiy Trotsenko (1) , A. V. Volotka (2) , D. Banas , H.F. Beyer (1) , Harald Bräuning (1) , Alexander Gumberidze (1) , S. Hagmann (1) , S. Hess (1) , Christophor Kozhuharov (1) , Regina Reuschl (1) , Uwe Spillmann (1) , Martino Trassinelli (1, 3) , G. Weber (1) , Thomas Stöhlker (1)

1 GSI - Helmholtz zentrum für Schwerionenforschung GmbH
2 USP - Department of Physics
3 INSP - Institut des Nanosciences de Paris

The two-photon 2E1 transition from the singlet 2s state of heliumlike tin was measured. An alternative experimental approach was adopted in the present investigation where the two-photon emission results from the decay of the 2s state by selective K-shell ionization of Li-like tin ions in relativistic collisions with a low-Z gaseous target, which allowed for a measurement of the undistorted two-photon spectral shape. The measured 2E1 energy distribution was compared with fully relativistic calculations, which predict a Z dependence of the distribution. The preliminary results indicate the best agreement with the relativistic many body calculations for tin, and thus confirm the sensitivity on Z. Detailed data analysis is still in progress.

Domaines: Physique Atomique [physics.atom-ph]

Ajay Kumar, Sergiy Trotsenko, A. V. Volotka, D. Banas, H.F. Beyer, et al.. Spectral shape of the 2E1 decay from 2s state in He-like tin. The European Physical Journal. Special Topics, 2009, 169, pp.19. ⟨10.1140/epjst/e2009-00967-x⟩. ⟨hal-00430948⟩