1. m.apollonioMICE UK- RAL- 2/5/20071 MICE beam diffuser M. Apollonio,P. Lau, W. Lau, J. Tacon, S. Yang – Univ. Oxford

2. m.apollonioMICE UK- RAL- 2/5/20072 0. Z=-6010 mm for the upstream face of the diffuser. This is a figure established long time ago (CR, CM14 Osaka - 2006) 1. radial size  R as big as possible 2. thickness  limited number of discs to fulfil MICE configurations 3. mechanics & control  design still evolving a) new carousel wheel (to cope with high moment of Inertia) b) motors c) ideas for control (logic)

3. m.apollonioMICE UK- RAL- 2/5/20073 LEADING IDEA trying to exploit all the radial space (15 cm) within the tin can envelope being compatible with mechanical contraints

4. m.apollonioMICE UK- RAL- 2/5/20074 7mm 15.5cm Emi inflation in single layer lead diffuser: 2.8  6.1 mm rad 7mm emi(after diff)=6 mm rad Muons selected on the overall channel ideal disc

5. m.apollonioMICE UK- RAL- 2/5/20075 7mm 5cm 15.5cm Emi inflation with a single layer of lead (small radius): 2.8  5.3 mm rad 7mm

6. m.apollonioMICE UK- RAL- 2/5/20076 7mm 5cm 15.5cm Emi inflation in a staggered lead diffuser: 2.8  6.1 mm rad 7mm a more realistic diffuser fixed annulus movable disc + support

7. m.apollonioMICE UK- RAL- 2/5/20077 emi(R)/emi(R=30 cm) R_diffEmittance bias as a function of R_diff (partial inflation) Pz=209 MeV/c, emi=10mm rad, B=4 T Pz=148 MeV/c, emi=10mm rad, B=2.9 T Pz=267 MeV/c, emi=10mm rad, B=4 T single disc staggered discs

8. m.apollonioMICE UK- RAL- 2/5/20078 10 mm Proposal to accommodate many configurations  STAGGERED/TAPERED with a fixed external annulus …just a sketch (see Peter/Joseph drawings) 24 to 27 cm 30 cm trackerdiffuser envelope Supports (outer can/disc support): Al Pb diffuser disc and outer annulus 1.5 to 15.5 mm

9. m.apollonioMICE UK- RAL- 2/5/20079 J. Tacon … the real thing

10. m.apollonioMICE UK- RAL- 2/5/200710 = 1.4 mm rad un-normalized How many configurations we need? want? …

11. m.apollonioMICE UK- RAL- 2/5/200711 … maybe 5 discs are enough (at least to begin with)

12. m.apollonioMICE UK- RAL- 2/5/200712 New design for the main carousel: location of air-motors

13. m.apollonioMICE UK- RAL- 2/5/200713

14. m.apollonioMICE UK- RAL- 2/5/200714 0.61 T 0.32 T 0.53 T B>= 4T B (T) Z (m) R (m) air-motors in the magnetic field  can they work ?

15. m.apollonioMICE UK- RAL- 2/5/200715 Diffuser Control Flow Chart: main cycle Command: set disc-f for run mode Start: go to Nf TH empty (  S off)? Which disc is in? Nd Move C to position N d Extract disc Go to empty station Move C to position Nf Insert disc Go to empty station STOP NB: need to know WHICH disc is in !

16. m.apollonioMICE UK- RAL- 2/5/200716 SUMMARY diffuser plates will be staggered/tapered discs of 12.5 cm diameter + outer annulus thicknesses nearly finalized some re-design of the mechanics needed controls in progress: optical sensors +  switch encoding/markers (for wheel position) air-motors + gear-boxes: possible SHOW STOPPERs !!!