EMuS – A Pulsed Muon Facility for Multidisciplinary Research

A pulsed muon facility (the so‐called EMuS) at the China Spallation Neutron Source (CSNS) has been studied since 2007. It aims for multidisciplinary applications but with a focus on those based on muon spin rotation/relaxation/resonance techniques. As a standalone facility, EMuS will take about 5% or 25 kW of the total beam power (500 kW) from the CSNS‐II accelerator complex. Two schemes have been designed: the baseline scheme is based on an inner conical target in graphite and superconducting solenoids for the capture and transport of pions and muons; the simplified scheme is based on a conventional thick target and room‐temperature magnets for transport. With the former, multiple kinds of muon beams can be provided, from surface muons, decay muons, negative muons, to low‐energy muons. Mainly surface muons are available with the simplified scheme. With a number of novel design concepts such as forward capture of pions/muons from a target station based on superconducting solenoids and triple spatial beam splitting of a muon beam, the design aspects of EMuS are presented here. The wide application potential and the R&D progress are also included. At the Experimental Muon Source at the China Spallation Neutron Source, a novel target station design is adopted to produce high‐intensity and different muon beam types. A conical graphite target is installed inside a series of superconducting solenoids. With a tapered magnetic field and forward collection, surface muons, decay muons, and high‐momentum muons can be provided in the downstream beamline.