Hannover 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
A: Fachverband Atomphysik
A 4: Photoionization I (exchanged with A1)
A 4.1: Hauptvortrag
Montag, 8. März 2010, 16:30–17:00, F 303
A hitherto unrecognized source of low-energy electrons in water — •Melanie Mucke1, Markus Braune2, Silko Barth1, Marko Förstel1,3, Toralf Lischke1, Volker Ulrich1, Tiberiu Arion1, Uwe Becker2, Alex M. Bradshaw1,2, and Uwe Hergenhahn1 — 1Max-Planck-Institut für Plasmaphysik, EURATOM association, Boltzmannstr. 2, 85748 Garching — 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin — 3Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg
Our experiments focus on the investigation of water clusters by electron-electron coincidence spectroscopy. The clusters were generated by supersonic molecular expansion of water vapour. After photoionisation of an inner valence electron by synchrotron radiation (BESSY, Berlin) an ultrafast non-local autoionisation process can occur. This so-called Intermolecular Coulombic Decay (ICD) leads to the ejection of two electrons, a photoelectron from molecule A and an electron of very low kinetic energy emerging from molecule B within the same cluster. This process is faster than a possible proton transfer and will thus efficiently generate these slow electrons. ICD can be triggered by any radiation of sufficient energy, but may as well take place as a secondary process following e.g. Auger decay. Therefore it is easy to imagine that there will be a wealth of low energy electrons generated wherever a watery environment is given, e.g. in biological tissue, and thus radiation damage might occur.