1. MICE analysis meeting - (18/5/2006) 1 STEPIII: ICOOL vs G4MICE M. Apollonio – University of Oxford

2. MICE analysis meeting - (18/5/2006) 2  These are very preliminary results of a work in progress  Joint effort between me and Chris who provided the code and relevant cards (and beam) to produce the G4MICE simulation  NO material in the channel (no absorbers)  Currents in G4MICE adapted to reproduce the currents I found for the ICOOL study of STEPIII  Some check on geometry/positioning of the coils  COMPARISONs:  G4MICE(simul.) + G4MICE(beam)  ICOOL(simul.) + G4MICE(beam)  ICOOL(simul.) + ICOOL(beam)  ICOOL beam= 207 MeV/c, 10% Pz spread, e_T(0) = 6mm rad

3. MICE analysis meeting - (18/5/2006) 3  ICOOL field (with ICOOL beam)  G4MICE field (with G4MICE beam)  ICOOL field (with G4MICE beam)  Shift by 2.225 m: realign

4. MICE analysis meeting - (18/5/2006) 4  ICOOL beta (with ICOOL beam)  G4MICE beta (with G4MICE beam)  ICOOL beta (with G4MICE beam)  Use the offset of 2.225 m  NB: the beta valley (centered in the ICOOL+ICOOL case) has a residual offset (~15 cm)

5. MICE analysis meeting - (18/5/2006) 5  ICOOL Pz (with ICOOL beam)  G4MICE Pz (with G4MICE beam)  ICOOL Pz (with G4MICE beam)  Different choices for the initial momentum  Remark: my current optimization was done for Pz=207 MeV/c  Pz(out) = Pz(in), but there’s a small (0.5%) increase in Pz in the case of ICOOL sim using G4MICE beam  ???

6. MICE analysis meeting - (18/5/2006) 6  ICOOL e_T (with ICOOL beam)  G4MICE e_T (with G4MICE beam)  ICOOL e_T (with G4MICE beam) Pure ICOOL shows a 1.5 % emittance growth ICOOL + G4MICE ~ 15% G4MICE + G4MICE ~ 25 % (plus some happy spikes)

7. MICE analysis meeting - (18/5/2006) 7 Conclusions  Basically the G4MICE code (with the relevant specifications for coil geom+current) seems to produce a Bz consistent with ICOOL sim.  Beta functions start being reasonably ok, but still there’s a shift of the centre + some difference in width  Pz nearly ok  e_T show completely different beahviours: particularly worrying the G4+G4 calculations (huge increase in e_T and strange spikes)