The Bulk µSR Group develops µSR instruments making use of positive muons with impulses ranging from 28 to 110 MeV/c.
- Conventional "surface" muons (with an energy of 4.1 MeV corresponding to an impulse of 28 MeV/c) are used on 4 different instruments with a large range of temperatures and magnetic fields available. Such muons have a typical range of 180 mg/cm2 in matter and are used for "standard" bulk samples.
- High-energy muons (with an energy of about 48 MeV corresponding to an impulse of about 110 MeV/c) are used on one instrument which is mainly dedicated to high-pressure studies. For such studies, the energy of the muons is necessary to penetrate into the massive walls of pressure cells which can hold up to 2.8 GPa. The simultaneous use of high-pressures and very-low temperatures makes such a facility unique in the world.