Berlin 2001 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

A: Atomphysik

A 12: Posters Thursday (Ion/Atom/Molecule/Surface Scattering)

A 12.22: Poster

Donnerstag, 5. April 2001, 12:30–15:00, AT3

ENERGY APPROACH TO CONSISTENT QED THEORY FOR CALCULATIONS OF ELECTRON-POSITRON PAIR PRODUCTION IN HEAVY IONS COLLISIONS AND ELECTRON COLLISION STRENGTHS — •Svetlana Malinovskaya — Computer Centre, P.O.Box 116,Odessa-9,65009,Ukraine

A consistent unified QED approach (operator perturbation theory) is adapted to collisional problems: the electron-positron pair production (EPPP) in collisions of two heavy nuclei (U) and calculation of the electron collisional strengths and rate coefficients for neon like ions. A consistent operator perturbation theory approach to a electron-nuclear system as a whole is used account being taken of the relativistic nature of the electron subsystem. The model potential of the whole electron-nuclear system accounts the finite size of nuclei and possible resonances of the super-heavy compound nucleus formed from original nuclei. The calculation is carried out for the case of the U-U collision. The cross-section of this process depends on the collision energy and the positron energy. The calculation leads to principally the same physical picture as a calculation with one-pocket potential besides the appearance of the pronounced peak. The possibility of treating of the positron spectrum narrow peaks as resonances states of the compound superheavy nucleus is analyzed. First numeral results on electron collisional strengths and rate coefficients are presented for neon like ions (Fe, Ar) and compared with results of Ivanov L. et al.