The Neutrino Factory is a type of proposed particle accelerator complex intended to measure in detail the properties of neutrinos, which are extremely weakly interacting fundamental particles that can travel in straight lines through normal matter for thousands of kilometres.
The source of the neutrinos would be the decay of accelerated muons in straight sections of a storage ring.
CERN., the use of Fixed Field Alternating Gradient (FFAG) accelerators, under test in the EMMA experiment, and liquid hydrogen energy reduction cavities for reducing the divergence in the muon beam during the intermediate stages.
This is based on an unusual type of accelerator called an Fixed Field Alternating Gradient (FFAG) that combines elements from the cyclotrons of the 1950s with modern automated magnet design processes, and new magnetic alloy radiofrequency accelerating gaps.
The main advantage of these is that the magnetic fields are fixed and do not have to be synchronised to the beam in any way, yet the beam naturally moves into regions of higher field as its energy increases, allowing for very rapid acceleration without the difficulties found in very rapid-cycling synchrotrons.