An introduction to MICE (Muon Ionisation Cooling Experiment) (A particle physics experiment)

Why build MICE? If antimatter and matter are exactly equal but opposite, then why is there so much more matter in the universe than antimatter? Studying neutrino “oscillations” could help explain the mechanisms behind this imbalance. Image courtesy of Fermilab

A “Neutrino Factory” Muon Decay In just 2.2 millionths of a second! MICE goes here In just 2.2 millionths of a second!

What does MICE do? Muon beams do not lend themselves to acceleration: Large beam size Large momentum range What physicists call “high emmittance” The best option currently envisaged to improve these properties is Ionisation Cooling This means taking momentum away from the muons (i.e. slowing them down) in “Absorbers” and then only giving it back in the direction you want (i.e. accelerating in the direction of the beam using RF). MICE will eventually contain 3 Absorbers and each one will be filled from a dedicated hydrogen delivery system The MICE beamline (below) The Hydrogen Absorbers

Project Background An essential step in accelerator R&D towards the next generation of accelerator physics research. An international collaboration comprising some 140 physicists and engineers from Belgium, Italy, Japan, the Netherlands, Russia, Switzerland, the UK and the US. In addition to a Neutrino Factory, Muon Cooling is also important for a new generation of accelerators beyond the LHC (Muon Colliders). Although there is a high level of confidence that Ionisation Cooling will work, it has never been done in practice – lots of engineering challenges.

Hydrogen Delivery System Liquid hydrogen offers the best ratio of momentum reduction through ionisation (‘cooling’) to multiple scattering of the beam (‘heating’). It is the best choice to achieve the physics requirements of the experiment, but not the easiest from an engineering point of view. Each Hydrogen Delivery System in MICE is designed to fill an Absorber with 22L of liquid hydrogen in a controllable and safe manner. Prior to use with the final MICE absorbers, the system will be tested with a Test Cryostat which represents the final absorber (this is the “R&D system”) System schematic Parts of the R&D Test Cryostat in manufacture CAD image of Absorber (in yellow) within its magnetic module