Naslov
Double ionization of He atom in high energy Compton scattering

Autori
Kaliman, Zoran ; Pisk, Krunoslav ; Surić, Tihomir

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Europhysics conference abstracts / Dunseath, K.M.Terao-Dunseath, M. - Pariz : Europian Physical Society, 2004, 4-47

Skup
8th EPS Conference on Atomic and Molecular Physics

Mjesto i datum
Rennes, Francuska, 06.07.2004. - 10.07.2004

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Compton scattering; correlations; helium; double ionization

Sažetak
We have calculated in second order perturbation theory the cross sections for double ionization of He atom, during the process of high energy Compton scattering. In this process we assume that one of the ejected electrons is fast, while the second is slow. The amplitude for the process is described by Feynman diagram in which the Compton collision of incident photon is followed by (ejected) electron -- (bound) electron interaction, which produces double ionization. This picture includes both shake--off mechanism and TS1 mechanism. The initial state of He-atom is described by variational wave function with effective charge, and the final ejected electron states are described by continuous Coulomb wave functions for Z=2. For the intermediate states we assume plane waves for the free electron, and only ground state of He(+) ion. For electron--electron interaction we use static Coulomb potential, and because the high energies are involved we also consider the spin--orbit coupling, which results in the spin triplet for the final electron state. Spin orbit coupling enables ejection of the second electron by spin--flip mechanism. The importance of this mechanism increases with increasing photon energy. In this work we present the calculations for cross sections of double ionization in Compton scattering process as a function of incoming photon energy and the angle of the scattered photon. Within our approach we discuss the correction to the high energy shake result for double ionization in Compton scattering. We also discuss the importance of spin-flip mechanism for Compton double ionization.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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