m.apollonioAM STEPIII – sizes and positioning m.apollonio, Oxford

m.apollonioAM Define current for 207  193 MeV/c Beta evolved with a step-like Pz change Pz=207 MeV/c Pz=195 MeV/c

m.apollonioAM CASE A – absorber in the middle

m.apollonioAM mm rad +12% 3 mm rad +0.3% Emi inflation  beta reduction  mismatch Pz = 207 MeV/c +/- 20% 195 MeV/c

m.apollonioAM mm rad -2% 10 mm rad -1.7%

m.apollonioAM CASE B – absorber inside the II solenoid

m.apollonioAM mm rad +3% 3 mm rad -2.5% Pz = 207 MeV/c +/- 20% 195 MeV/c

m.apollonioAM mm rad -3% 10 mm rad -3%

m.apollonioAM R=16  =42 cm (Pz=200 MeV/c) R=20.7  =70 cm (centre) NB: radial size to be scaled according to BETA

m.apollonioAM SUMMARY 0. emi growth in vacuum ~ 6 mm rad, 10 mm rad a) absorber in the middle reduced cooling 6 mm rad) much easier insertion scheme radial size must be increased (20.7 cm), which could be incompatible with LH FC dimensions b) absorber inside solenoid gives an enhanced cooling 6 mm rad) requires some difficult insertion scheme radial size small (16 cm) and easy to insert LH in FC (a)Poorer performance but much more practical (b)Better performance but not very practical