A novel set-up for fast muon-spin-rotation experiments

A novel set-up for fast muon-spin-rotation experiments with an effective ti me resolution of (150 +/- 10) ps (full-width at half-maximum) of the 'promp t peak' is described. A new method of extending the histogram length of the hitherto existing data-acquisition system allows the use of the full time range of the clock with a histogram length of approximately 5 mu s and pile -up and second-muon gates with the same length. The whole electronics consi sts of only four NIM modules and an EG & G Ortec 'Picosecond Time Analyzer' mod. 9308 connected to a personal computer. The performance of the novel s pectrometer is demonstrated in measurements of the hyperfine precession fre quency of muonium in fused quartz, liquid water, and different silsesquioxa nes at room temperature. (C) 2000 Elsevier Science B.V. All rights reserved .