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A: Atomphysik

A 5: Posters Tuesday (Photoionisation, Multi Photon Processes)

A 5.36: Poster

Dienstag, 3. April 2001, 12:30–15:00, AT3

Approximate treatment of the relativistic two-photon bremsstrahlung process. — •Igor Solovjev, Tatiana Fedorova, and Andrei Korol — Department of Physics, St.Petersburg State Maritime Technical University, Leninskii prospect 101, St.Petersburg 198262, Russia

We propose an approximation for effective quantitative analysis of the processes the amplitude of which contains, as a constituent part, the radiative free-free matrix elements between two states one of which (or both) is a virtual state (e.g. two-photon bremsstrahlung). The exact relativistic evaluation of compound matrix elements is extremely cumbersome, and for many processes such a problem has not been solved so far. The approach we propose [1], although being approximate, allows to effectively evaluate the main parts of the free-free matrix element with much less analytical and computational efforts. It is based on the accurate analytical treatment of the diagonal singularities in the one-photon matrix elements which appear in the compound matrix element.

We illustrate the applicability of the method by presenting the results of calculations of spectral and angular distributions for two-photon bremsstrahlung process and their comparison with available experimential data and more simpler approximations.

This work is partially supported by RFBR grant 99-02-18294a.

[1] T.A.Fedorova, A.V.Korol, I.A.Solovjev, J.Phys.B: At.Mol.Opt.Phys. 33 (22), 5007 (2000)