Bonn 2000 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MO: Molekülphysik
MO 7: Photoionisation I (gemeinsam mit FV Atomphysik)
MO 7.3: Vortrag
Dienstag, 4. April 2000, 14:30–14:45, HS I
Triple photoionisation of lithium: from high energies to threshold? — •Thomas Pattard1 and Joachim Burgdörfer1,2 — 1University of Tennessee, Department of Physics, 401 Nielsen Physics Building, Knoxville, TN 37996-1200, USA — 2Technische Universität Wien, Institut für theoretische Physik, Wiedner Hauptstr. 8-10, A-1040 Wien, Austria
Multiple ionisation of atoms or ions by a single photon is a fundamental process. Nevertheless, its treatability by analytical as well as numerical methods is limited. Numerical ab initio methods are capable of producing ionisation cross sections with a high degree of accuracy; however they are currently limited to problems with two active electrons. On the other hand, recent experimental studies on the triple ionisation of lithium call for a theoretical treatment of the problem. In this contribution we will present a simple physical model which decomposes the triple ionisation process into numerically treatable parts. We will show that this picture — which originates from an expansion for high photon energies — is capable of providing a reasonable description of the triple ionisation cross section over a surprisingly wide energy range. The underlying physical picture should therefore contain the dominant mechanisms of the break–up process.