200 MHz cavity for a Muon Ionization Cooling Experiment (MICE)
JLab is helping to build the first prototype 201.25 MHz copper cavity for the muon ionization cooling experiment (MICE), proposed for Rutherford Lab in the UK.. This cavity was developed by the US MUCOOL collaboration and will be tested first in the new Muon Test Area at Fermilab. The cavity fabrication uses various metal forming and joining methods to produce the final cavity shape. These include spinning, brazing, TIG welding, electron beam welding, electron beam annealing and deep drawing. Some of the methods developed for this cavity are novel and offer significant cost savings compared to conventional construction methods.
Ionization cooling is a method to increase the phase-space density of a beam of muons produced through pion decay downstream of a high-power target. The muons in turn decay to produce neutrinos that are of great interest for high-energy physics experiments. At present the only sources of neutrinos physicists have to study are from the sun, distant stars and nuclear reactors on earth. A controlled beam of neutrinos that can be turned on and off would give a uniquely valuable signal to the vast underground detectors that currently exist or are being planned. There have been several studies already to show the feasibility of such “neutrino factories”.
Such a beam of muons, once sufficiently “cooled” to fit into a conventional accelerator could also be accelerated to very high energy, put into a storage ring and collided. Such a “muon collider” offers potential energy reach beyond the LHC and ILC because muons have 200 times the mass of electrons so they emit much less synchrotron radiation, but unlike protons they are fundamental particles so all their energy is available to make new particles in a collision.
The MICE experiment is aimed at demonstrating the practical implementation of a small section of cooling channel that could form the basis of a neutrino factory. It is an international collaboration between European, US and Japanese Labs and universities.
200 MHz cavity in the e-beam welder at NASA Langley
