Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 1 Measuring emittance with the TOFs Data: –G4MICE has been used to obtain transfer matrices using simulations of beams between TOF0 and TOF1 of varying emittances Questions: –Can we check that the G4MICE transfer matrices are reasonable? –How good is a transfer matrix at transporting the beam: what are the RMSs? –What can we say about the cause of the spreads on the Mij? –How significant will the errors due to the spreads on the Mij be in reconstructing the phase plane and measuring emittance?

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 2 Deducing M ij from G4MICE MC: a drift length Drift length 1150mm Care required in binning: It works! Re-binning

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 3 Deducing M ij from G4MICE MC: quadrupole triplet Discrepancies between TDR and G4MICE –Separation of Q7, 8 and 9 quadrupole centres –dB/dx for Q7, Q8 and Q9 –Although, the quadrupole effective length is nominally the same, G4MICE end field models don’t preserve this exactly

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 4 TOF0  TOF1, x plane 4

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 5 TOF0  TOF1, y plane 5

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 6 Ckov, x plane 6 s=0.8m

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 7 Q789, x plane 7

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 8 8 Q7, x plane

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 9 9 Q8, x plane

Mark Rayner 26/8/08Analysis Meeting: Emittance measurement using the TOFs 10 Emittance measurement using the TOFs Step 1: Do a simulation to determine the transfer matrix between the TOFs using MC truth –Observe spreads on the results of the Mij calculations Step 2: Measure the positions in both TOFs for each muon –Error = slab width / root 12 ~ 2 cm Step 3: Estimate x’ at TOF1 for each muon (Step 4: Calculate emittance) Do we expect  x k ) or  M ij ) to contribute most to  x’ 1 ) using this method? –Contributing to  2 (x’ 1 ): Factors of M ij multiplied by  2 (x k ) Factors of RMS beam size and M ij multiplied by  2  M ij )