Pulsed positron beams can out perform conventional positron lifetime systems by orders of magnitude in both event rate and peak to background ratio. The actual performance of low energy pulsed positron beams, however, is is still far from its limits. The technical reasons are spotted and possible improvements are discussed with respect to over ten years of technical developments performed at Munich. Improvements like reduction of the pulse period to 50 MHz, saw-tooth prebuncher, pre-chopper and redesign of the sample chamber which were performed in our currently running system (version 2) are shown. It is argued, that the third version (now under construction) will finally accumulate 104 counts/s at a peak to background ratio of 105. We also show plans of a rf-accelerator for a pulsed variable energy positron beam with source and sample on ground potential.    «

Pulsed positron beams can out perform conventional positron lifetime systems by orders of magnitude in both event rate and peak to background ratio. The actual performance of low energy pulsed positron beams, however, is is still far from its limits. The technical reasons are spotted and possible improvements are discussed with respect to over ten years of technical developments performed at Munich. Improvements like reduction of the pulse period to 50 MHz, saw-tooth prebuncher, pre-chopper and...    »