Muon-spin relaxation/rotation(μSR)

For the muon-spin relaxation/rotation technique(μSR), positive muons are implanted into a material where they come to rest these decay with a half-life of 2.2μs into a positron and two neutrinos. Since the decay positron is preferentially emitted along the direction of the muon-spin the distribution of the detected positrons provides information about the local magnetic field at the muon stopping site this technique is therefore a highly sensitive probe of the size distribution and dynamics of the local magnetic fields inside a material. μSR is also an important tool for measuring superconductors where it can be used to detect the spontaneous emergence of small magnetic fields when a material becomes superconducting. Furthermore, if a large enough magnetic field is applied to a type-ll superconductor, a magnetic flux line lattice is formed μSR measurements of this state can reveal the magnetic penetration depth of a superconductor, which is an important way of determining the symmetry of the superconducting order parameter. We perform μSR measurements at various international facilities in particular the ISIS facility in UK and PSI in Switzerland.

A μSR instrument at the ISIS Pulsed Neutron and Muon facility in UK