MOLECULAR UNIVERSE

Expertise in Research and Complementarity
The Nijmegen group has a long tradition in research on molecular collisions, focusing on the dynamics of small interstellar molecules, such as OH, H₂CO and NH₃, in inelastic collisions. 30 years ago, a molecular beam maser was constructed at Nijmegen, in order to investigate the interstellar OH maser mechanism. Soon this was followed by collision experiments on NH₃ and H₂CO in a molecular beam maser. With the advent of sensitive laser techniques, microwave detection was replaced by laser-induced fluorescence detection, which was applied first to study D₂CO collisions in a crossed molecular beam setup and later to NH₃ using pulsed techniques. In the last decade extensive studies have been performed on inelastic state-to-state scattering of OH molecules by species such as Ar, He and H₂, enabled by the development of an intense pulsed OH beam source. At present, steric effects in state-to-state collisions are probed by orienting the OH molecules towards the collision partner in an electric field. Photodissociation of H₂ as a source of interstellar OH molecules has been studied in collaboration with the University of Bielefeld. At present reactions of OH radicals are being investigated, such as OH + HCl H₂ + Cl and OH + CO CO₂ + H. The collision research forms a main research program in the Applied Physics group in addition to applied research projects focused on the development and application of laser diagnostics to study molecular dynamics in a wide variety of physical and chemical processes. The Nijmegen team is lead by Professor J.J. ter Meulen (JJtM) who has a broad experience in molecular spectroscopy, molecular dynamics and applied laser physics (over 130 publications). The team closely collaborates with the Molecular and Laser Physics groups of Prof. Parker and Prof. Van der Zande. The group of Parker is world leading in the field of velocity map imaging, which is part of the planned experiments. The group participates in the European research training network on experimental and theoretical studies on the dynamics of reactions of atoms and radicals of fundamental and practical importance. In this network a close collaboration exists with experimental groups from Perugia and Oxford and the theoretical group in Madrid.
Expertise in Training and Knowledge Transfer
The junior researcher (JR) would be employed within the Nijmegen School and Research Institute of Materials (NSRIM), which is a joint research school of Chemistry and Physics. The JR is expected to attend courses and summer schools on various general and special topics in chemical physics as well as the weekly joint colloquia of the Applied Physics and Molecular and Laser Physics groups. The University of Nijmegen provides a broad training and education programme for JRs, including courses to train academic skills, such as ``Reflection on the exercise of scholarly work'' and ``Academic writing''. Group members are stimulated to to present their work at national and international conferences. Over the past four years, JJtM has supervised 12 PhD students (10M, 2F), of whom 6 have graduated and 6 are current students, as well as 5 PDFs (2M, 3F), of whom 3 are current.

Involvement of Key Scientific Staff.

Significant References
1. M.C. van Beek, J.J. ter Meulen and M.H. Alexander, Rotationally inelastic collisions of OH(X) + Ar. II. The effect of molecular orientation, 2000, J Chem Phys, 113, 637
2. M.C. van Beek, G. Berden, H.L. Bethlem and J.J. ter Meulen, Molecular reorientation in rotationally elastic collisions of OH + Ar, 2001, Phys Rev Lett, 86, 4001