Conceptual design of MuSR spectrometer for EMuS using Monte Carlo simulation

Abstract

The Muon Spin Rotation/Relaxation/Resonance (MuSR) technique uses a muon beam to probe the structure and dynamics of matter at a microscopic level. An experimental muon source (EMuS) will be built at the China Spallation Neutron Source (CSNS). A MuSR spectrometer was proposed to be constructed in a sub-branch of EMuS. In this contribution, the size of the scintillator and light guides of the polarized MuSR spectrometer were optimized by Geant4. The simulation shows that a scintillator with a length of 175 mm can cover a large solid angle (43%) and get a good detection efficiency and collection efficiency. Double counts can be minimized with a scintillator thickness of 5 mm.