First experience with G-APDs in μSR instrumentation

In this work we demonstrate the potential of G-APD based detectors for the development of the μSR technique. For the 5 T Avoided Level Crossing instrument located at the Swiss Muon Source of the Paul Scherrer Institut (PSI, Villigen, Switzerland) we are building a completely new detector system using as a basic element a tile-fiber scintillation counter with a G-APD readout. For the planned 10 T high magnetic field spectrometer we are carrying out feasibility tests aiming at the highest possible time resolution. A counter constructed as a G-APD directly coupled to a fast plastic scintillator was tested at detection of minimum ionizing electrons from a 90Sr source. With about 0.33 MeV deposited energy the time resolution of σ=35ps has been measured.