Experimental Muon Source (EMuS) Target Station Shielding Design for "Baby Scheme"

The Experimental Muon Source (EMuS) project at China Spallation Neutron Source (CSNS) in Dongguan aims at building a competitive muon source providing both a low energy surface muon beam and a high energy decay muon beam for muon science. Highly polarized positive surface muons are used in muon spin rotation (μSR) spectrometers in order to study material properties in condensed matter physics, chemistry and biology. Especially in studying magnetic systems; higher momentum muons can be employed in non-invasive analysis of materials, such as bulk-sensitive elemental analysis with negative muons, or muon radiography techniques. EMuS uses up to 25 kW proton beam hitting on a graphite target to produce the muon beam with a conventional magnet side collection target station and an advanced forward superconducting solenoid capture target station, so called as “Baby scheme" and “Baseline scheme" respectively. Extremely high radiation produced from the target has to be shielded in order to safeguard the magnet system and the surrounding environment for proper functioning and operation. Therefore, a proper shielding of magnet and environment becomes a key factor of its successful design. We present here the preliminary design and application of hybrid nature of shielding for the EMuS experiment for “Baby scheme".