Darmstadt 2008 – scientific programme

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A: Fachverband Atomphysik

A 27: Posters: Electron scattering and recombination

A 27.7: Poster

Thursday, March 13, 2008, 16:30–18:30, Poster C3

Spin-resolved electron scattering on lead (Pb) and bismuth (Bi) atoms — •Volker Hamelbeck, Philipp Brüner, and G. Friedrich Hanne — Physikalisches Institut, 48149 Münster, Germany

The physics of interactions between low-energetic spin-polarised electron beams and atomic as well as molecular targets have comprehensively been studied in our group. An interesting aspect of this field are collision experiments on heavy metal atoms such as Pb and Bi where spin-orbit and exchange effects occur simultaneously. This is still a difficult task for theory.
For a description of these processes, the scattering parameters S_P, S_A, T^→ and U^→ are introduced. Through the polarisation function S_A the spin-dependence of the DCS is quantified. The other parameters are determined by measurement of P^→ and P^→′, the electron polarisation before and after scattering respectively.
In such an experiment, the spin-polarised electron beam is guided from a GaAs source to the collision centre where it hits the heavy metal vapour emanating from an oven. A rotatable spectrometer is used to collect the scattered electrons whose spin polarisation is subsequently determined in a Mott-detector.
At the conference, details of the apparatus and current results will be presented. Through further investigations, we will gain a deeper insight into the physics of collisions between spin-polarised electrons and atoms.