Positron annihilation lifetime spectroscopy at a superconducting electron accelerator

14th International Workshop on Slow Positron Beam Techniques & Applications

Wagner, A.^1 ; Anwand, W.^1 ; Attallah, A.G.^2,3 ; Dornberg, G.^4 ; Elsayed, M.^2 ; Enke, D.^4 ; Hussein, A.E.M.^2 ; Krause-Rehberg, R.^2 ; Liedke, M.O.^1 ; Potzger, K.^5 ; Trinh, T.T.^1,6

Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstraße 400, Dresden

01328, Germany^1

Martin-Luther-Universität Halle, Institut für Physik, Halle

06099, Germany^2

Physics Department, Faculty of Science, Minia University, El-Minia

61519, Egypt^3

Institute of Chemical Technology, Universität Leipzig, Leipzig

04103, Germany^4

Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, Dresden

01328, Germany^5

Technische Universität Dresden, Dresden

01062, Germany^6

关键词: Defect spectroscopy;    Positron annihilation lifetime spectroscopy;    Positron annihilation lifetimes;    Positron lifetime;    Positron sources;    Pulse separations;    Repetition rate;    Superconducting linear accelerators;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/791/1/012004/pdf
DOI  :  10.1088/1742-6596/791/1/012004

来源: IOP

【 摘 要 】

The Helmholtz-Zentrum Dresden-Rossendorf operates a superconducting linear accelerator for electrons with energies up to 35 MeV and average beam currents up to 1.6 mA. The electron beam is employed for production of several secondary beams including X-rays from bremsstrahlung production, neutrons, and positrons. The secondary positron beam after moderation feeds the Monoenergetic Positron Source (MePS) where positron annihilation lifetime (PALS) and positron annihilation Doppler-broadening experiments in materials science are performed in parallel. The adjustable repetition rate of the continuous-wave electron beams allows matching of the pulse separation to the positron lifetime in the sample under study. The energy of the positron beam can be set between 0.5 keV and 20 keV to perform depth resolved defect spectroscopy and porosity studies especially for thin films.