The Pulsed Low-Energy Positron System PLEPS  is a user facility for defect depth-profiling by means of positron lifetime measurements with a monochromatic pulsed positron beam of variable energy ranging from 0.5-21 keV at the intense positron source NEPOMUC at the MLZ in Garching .
To further extend the scope of defect characterization of PLEPS various possibilities of in-situ manipulation of the sample during lifetime measurements have been implemented: To drift positrons to layers, interfaces and surfaces it is now possible to apply electrical fields to the sample. A wave-length selective broadband illumination system was installed to manipulate the charge-state of optically active defects. Also, the sample temperature may be varied between 80 K and 600 K. The data-acquisition system was updated to match recent advances at the NEPOMUC remoderator . Moreover, numerical simulations of crucial pulsing components have been conducted to further improve the performance of PLEPS.
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