TUNE MEASUREMENT IN NON SCALING FFAG EMMA WITH MODEL INDEPENDENT ANALYSIS

The Non Scaling Fixed Field Alternating Gradient (NSFFAG) EMMA accelerator has a purely linear lattice, and the crossing of resonances during acceleration is therefore a key characteristic of the beam dynamics. An accurate measurement of the tune is essential for a full understanding of the machine behaviour. However, commonly used measurement techniques require the beam to perform a large number of turns in the machine. Simulations have shown us that rapid decoherence of the beam requires a technique capable of providing a tune measurement from just one or two turns of the ring. Model independent analysis(MIA) has been investigated as a possible approach. The singular value decomposition of a matrix composed of BPM readings from the trajectories of different bunches provides information on the machine optics. Simulations indicate that it should be possible to derive an accurate value of the tune using MIA, even in the presence of BPM noise and beam decoherence.