Atomare Prozesse

Universität Hannover


Die Forschungstätigkeit der Abteilung dient der Aufklärung der Wechselwirkungen atomarer Partikel (Atome, Moleküle, Elektronen, Ionen, Photonen) und der Untersuchung von Elementarprozessen zwischen solchen Teilchen. Es wird sowohl experimentell als auch theoretisch gearbeitet. Außerdem werden apparative Entwicklungen betrieben, zum Beispiel die Entwicklung oder Untersuchung von Teilchenquellen und Teilchendetektoren.

Bedingt durch die Emeritierung von Prof. B. Brehm hat sich die Abteilung deutlich verkleinert und konzentriert die Forschungstätigkeit auf ein eng umrissenes Gebiet.

Zur Zeit werden folgende Themen bearbeitet: Die experimentellen Verfahren, die dabei eingesetzt werden sind:

Field of activity

Fundamental properties and processes of simple atomic and molecular systems are being investigated both experimentally and theoretically. At present, the main emphasis is on the investigation of laser-assisted collisions.

In consequence of the emeritation of Prof. B. Brehm the section has become smaller and concentrates their activities on a smaller field.

Current work is focused on the following topics:
  • Laser-excitation of collision pairs (Optical Collision)

    Experimental methods have been developed, which allow the direct observation of atomic or molecular collisions and the coherent control of elementar collision processes. We have already been able to make geometric observations of a collision complex ("photograph" of a collision). This is a remarkable success, because the object, which we observe, is both small (10-10m) and short lived (10-12s).
    With this method, sensitive tests of molecular potentials have been performed and nonadiabtic transitions have been analysed.
    It has been shown, that time resolved experiments of this type with femtosecond lasers can be done, too ("movie" of a collision).

    Keywords: optical collision, direct observation, coherent control, nonadiabatic transition, collision geometry, complex, transition state, molecular potential, optical excitation of collision pairs, atomic or molecular collision processes, photography of a collision, how a collision process proceeds.

  • Theoretical descripton of inelastic collision processes

    The inelastic cross-sections of atom-atom collisions at low energies play an important role for the calculation of non-equilibrium phenomena in diluted gases, e. g. atmospheres of stars or Laser plasmas. The inelastic cross-sections are obtained from completely quantummechanical ab-initio calculations. The results can be interpreted conspicuously.

The typical experimental methods are:
  • Atom, electron and ion beams,
  • Laser, light and particle optics,
  • Optical and particle spectrometers,
  • Infrared-spectroscopy,
  • Vacuum-ultraviolett-spectroscopy,
  • Single particle detectors,
  • Time resolved pulse detection, for instance coincidence techniques
  • on-line data aquisition using local area computer networks,
  • vacuum technology


Institut für Gravitationsphysik
Arbeitsgruppe Atomare Prozesse
Institut für Atom- und Molekülphysik
Abteilung Atomare Prozesse)
Callinstraße 38
D-30167 Hannover
Raum 126 oder 127,
Telephon (+49)511-762-2229, oder ...-17164
Telefax: (+49)511-762-5861, oder ...-2784

* Publikationen der letzten Jahre *