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A: Atomphysik
A 19: Electrons, incl. Scattering and Recombination
A 19.10: Vortrag
Freitag, 6. April 2001, 18:00–18:15, H1028
Electron-positron pair production in relativistic collisions of heavy ions — •M. Gail, N. Grün, and W. Scheid — Justus-Liebig-Universität Giessen
In collisions of heavy ions electron-positron pairs can be produced by the strong electromagnetic fields of the colliding ions. One distinguishes free pair production from pair production with capture of the electron into a bound state of an ion (bound-free pair production). For very small impact parameters perturbation theory becomes invalid and nonperturbative methods must be used for the proper description of the collision process. We use the coupled channel approximation with a basis set consisting of atomic wave functions centered around the projectile and the target nucleus. The continuum is discretized by employing wave packets. We have calculated cross sections for bound-free and free pair production in collisions of U92+ ions and La57+ ions with Au, Ag and Cu at a collision energy of 960 MeV/nucleon. We compare our results with experiments that have been performed by Belkacem et al. [1] at the BEVALAC. Wirkungsquerschnitten
[1] A. Belkacem, H. Gould, B. Feinberg, R. Bossingham and W. E. Meyerhof, Phys. Rev. A 56, 2807 (1997)