Regensburg 2004 – wissenschaftliches Programm
O 40.10: Vortrag
Donnerstag, 11. März 2004, 18:00–18:15, H45
Potential Energy Retention of Slow Highly Charged Ar-Ions in Chemical Clean Silicon Surfaces — •Daniel Kost, Stefan Facsko, and Wolfhard Möller — Institut für Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf, 01028 Dresden
A UHV device with a base pressure of p<10−9 mbar was connected to the ECR ion source of the Forschungszentrum Rossendorf for improved calorimetric measurements of the retention of the potential energy of highly charged ions. The chemical state of the target surface is controlled by AES using LEED optics. With a clean silicon surface prepared by sputtering using Ar+ ions, the retained energy of Arq+ (q = 1 up to 9) ions was determined at kinetic energies between 60 eV · q and 200 eV · q. By extrapolation to zero kinetic energy, the retained fraction of the potential energy is obtained, which is related to the full potential energy given by the ionization potentials. The potential energy retention coefficient results as 0.8 ± 0.2 and decreases weakly with increasing charge state. This is about three times larger than earlier results with contaminated copper surfaces.