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.