• Y. Giboudot
  Brunel University, Middlesex
• I. Kirkman, A. Wolski
  The University of Liverpool, Liverpool

The Non Scal­ing Fixed Field Al­ter­nat­ing Gra­di­ent (NS-FFAG) EMMA ac­cel­er­a­tor has a pure­ly lin­ear lat­tice and thus al­lows im­por­tant tune vari­a­tion. The cross­ing of res­o­nances dur­ing ac­cel­er­a­tion is a key char­ac­ter­is­tic of the beam dy­nam­ics. An ac­cu­rate mea­sure­ment of the tune is there­fore manda­to­ry. How­ev­er com­mon­ly used mea­sure­ment tech­niques re­quires the beam to per­form an im­por­tant num­ber of turns in the ma­chine. Sim­u­la­tions have shown that fast de­co­her­ence of the beam re­quires the study of an­oth­er mea­sure­ment tech­nique. The model in­de­pen­dent anal­y­sis (MIA) has been in­ves­ti­gat­ed. The sin­gu­lar value de­com­po­si­tion (SVD) of a ma­trix com­posed of sim­u­lat­ed BPMs read­ing of var­i­ous bunch­es tra­jec­to­ries gives a de­scrip­tion of the op­tics func­tion at each Beam Po­si­tion Mon­i­tor. In­clud­ing mis­align­ment er­rors and elec­tron­ic noise, an ac­cu­rate value of the tune has been de­rived from sta­tis­ti­cal treat­ment re­peat­ing this pro­cess few hun­dreds of time.

yoel.giboudot@stfc.ac.uk