Speaker
Thomas Gigl
Description
The positron beam facility NEPOMUC at the FRM II provides a mono-energetic positron beam with an intensity of 10^9 moderated e+/s. The CDB spectrometer at NEPOMUC enables depth dependent and spatially resolved defect studies by using conventional doppler broadening spectroscopy(DBS), and element-specific measurements with coincident DBS. For depth dependent measurements, the positron implantation energy can be adjusted from 0.5 to 30 keV. The lateral resolution amounts to 300 um.
For the development of a positron micro beam with a diameter of <5 um a 100 nm thick Ni(100) remoderation foil will be installed in transmission geometry to increase the beam brightness. To achieve a high yield of re-emitted moderated positrons, the Ni foil has to be annealed and surface contaminations such as carbon and oxygen have to be removed. Therefore, temperature-dependent XPS and DBS measurements were performed for characterizing the surface contaminations and for determining the annealing behaviour.
Primary author
Co-authors
Mr
Christian Piochacz
(Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department E21, Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany)
Christoph Hugenschmidt
Mr
Markus Reiner
(Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department E21, Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany)
