Programmes
EMMA
EMMA is a project to build a non-scaling FFAG (Fixed Field Alternating Gradient) accelerator at Daresbury Laboratory, as an addition to the ERLP/ALICE programme. Such an accelerator has never been built anywhere in the world and this radical challenge has been financed by the joint Research Councils Basic Technology fund.
FFAGs accelerate a beam of charged particles from low to high energy with particle orbits at different radii depending on the energy of the beam (like a cyclotron). However the beam is compressed to be contained within a torus-shaped vacuum chamber (like a synchrotron) and an FFAG is thus much more compact than a cyclotron. Together with other attractive properties this suggests a range of potential applications including charged particle cancer therapy, accelerator driven reactors and particle physics (e.g. neutrino factories).
EMMA is a small electron model designed as a proof of principle. The machine presents some interesting challenges. The focussing magnets have a standard quadrupole geometry but bending is achieved by offsetting the beam horizontally in them. However EMMA magnets have an extremely short length, meaning that their 'end effects' (which would be a small correction in a standard quadrupole) become dominant. Pairs of magnets are also very closely spaced around the ring and the magnets then have a non-trivial interaction. Full 3D modelling has been necessary from the outset to make sure a beam can be successfully injected, transported around the machine, accelerated from 10MeV up to 20MeV, and extracted for diagnostic purposes.
Funding for the project was granted to a UK consortium (CONFORM) from April 2007. This includes design study resources for a second ring, PAMELA, that extends the concept to a proton accelerator specification suitable for therapy. ASTeC also participates in this part of the project. The CONFORM grant provides funding until April 2011.
31 August 2010