Positronbeam for μm Resolved Coincident Doppler Broadening Spectroscopy at NEPOMUC

13th International Workshop on Slow Positron Beam Techniques and Applications

Gigl, T.^1,2 ; Piochacz, C.^1,2 ; Reiner, M.^1,2 ; Hugenschmidt, C.^1,2

Technische Universität München, Physik Department, Lehrstuhl E21, James-Franck-Straße, D-85748 Garching, Germany^1

Technische Universität München, Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Lichtenbergstraße 1, D-85748 Garching, Germany^2

关键词: Beam diameters;    Current status;    Doppler broadening spectroscopy;    High brightness;    High resolution;    Positron beams;    Sample position;    Transmission geometries;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/505/1/012032/pdf
DOI  :  10.1088/1742-6596/505/1/012032

来源: IOP

【 摘 要 】

A new high resolution coincidence Doppler spectrometer is under development at the positron beam facility NEPOMUC at the research neutron source FRM II. A Ni(100) re-moderation foil will be installed at the new spectrometer in transmission geometry for producing a positron beam with high brightness. Therefore, a magnetic lens for focusing the positrons onto the re-moderator and an electrostatic lens system for focusing the beam onto the sample have to be designed and simulated. The aim is to reach a beam diameter below 10 μm at the sample position for high resolution experiments. The current status of the project will be described and presented.