In this paper an overview on the modifications of the Munich pulsed low energy positron system is given. In particular the moderator section and the new prebuncher are described in detail. With a new preparation chamber for in situ annealing of the moderator and a new prebuncher the count rate has been increased by a factor of five. Due to the new master frequency of 50MHz (old system: 200MHz) the lifetime spectra have a length of 20ns. Long positron lifetimes can now be easily analysed. A faraday cage in front of the target station reduces strongly the perturbations of the spectra (high background, satellite peaks). Finally a new target station allows lifetime measurements at variable temperatures. The time resolution of the new system is 230ps (FWHM).    «

In this paper an overview on the modifications of the Munich pulsed low energy positron system is given. In particular the moderator section and the new prebuncher are described in detail. With a new preparation chamber for in situ annealing of the moderator and a new prebuncher the count rate has been increased by a factor of five. Due to the new master frequency of 50MHz (old system: 200MHz) the lifetime spectra have a length of 20ns. Long positron lifetimes can now be easily analysed. A farad...    »