Digital positron lifetime spectroscopy at EPOS

• Published in: Applied surface science 2008-10, Vol.255 (1), p.93-95
• Main Authors: Krille, Arnold, Krause-Rehberg, Reinhard, Jungmann, Marco, Bečvář, František, Brauer, Gerhard
• Format: Article
• Language: English
• Subjects: Charged-particle beams; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Digital positron lifetime; Electromagnetism; electron and ion optics; Electron and ion emission by liquids and solids; impact phenomena; Electron and positron beams; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Impact phenomena (including electron spectra and sputtering); Physics; Positron beam techniques; Positron emission; Pulse interpolation
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2008.05.215

As the digital equipment to measure positron lifetimes gets cheaper and more widely used, it is decided that EPOS, the ELBE positron source will sample the signals from the photomultipliers directly and evaluate it online or offline by digital means. Still using isotope sources, the EPOS lifetime spectrometer results in a timing resolution of around 170 ps (with 60Co), which compares good to analog equipment. A distinct improvement is expected when a coincidence setup will be used at ELBE. However, also the software needs further improvement: while one of the goals is of course to achieve the best time resolution, there is also the aspect of runtime and expandability. Results of evaluations will be presented and compared with results from other groups.