1. m.apollonioMICE Analysis meeting 23/1/20071 M. Apollonio – University of Oxford Radius of diffuser and sizes for PID

2. m.apollonioMICE Analysis meeting 23/1/20072 Let’s consider different optics for MICE Consider the maximum radius a particle can reach in the tracker (TK) = 15 cm the absorber (ABS) = 15 cm the RF windows (RF) = 21.3 cm It can be shown that  ~ Propagate the radius throughout MICE according to These curves represent the ENVELOPE of the beam which just touches the TK, the ABS, the RF and the diffuser == muons with a given amplitude == MAX size of diffuser MAX radii in the downstream region CAVEAT: field in the downstream region is approximate, neglecting the presence of the shield!!!

3. m.apollonioMICE Analysis meeting 23/1/20073 current diffuser position ideal minimum R D

4. m.apollonioMICE Analysis meeting 23/1/20074 Wang-200-42 Z-downstream: shield-in shield-out SW TOF KL

5. m.apollonioMICE Analysis meeting 23/1/20075 current diffuser position  inside TKs  inside ABS  inside RF ideal minumum R D Every  in the TKs will traverse both ABS and RF R D must be as large as possible 10 cm is definitely too small !!!

6. m.apollonioMICE Analysis meeting 23/1/20076 Wang 207-200-193 (with energy loss) R grows linearly far from the solenoid (beta ~ z 2 )

7. m.apollonioMICE Analysis meeting 23/1/20077 Wang-240-42

8. m.apollonioMICE Analysis meeting 23/1/20078 Wang-240-42

9. m.apollonioMICE Analysis meeting 23/1/20079 NF-200-42

10. m.apollonioMICE Analysis meeting 23/1/200710 NF-200-42

11. m.apollonioMICE Analysis meeting 23/1/200711 SFOFO-170-15

12. m.apollonioMICE Analysis meeting 23/1/200712 SFOFO-170-15

13. m.apollonioMICE Analysis meeting 23/1/200713 SFOFO-140-7

14. m.apollonioMICE Analysis meeting 23/1/200714 SFOFO-140-7

15. m.apollonioMICE Analysis meeting 23/1/200715 Summary of min R – DIFFUSER (cm)

16. m.apollonioMICE Analysis meeting 23/1/200716 6399.5 6499.5 6574.5 6649.5 6729.5 7429.5 6524.5 6599.5 6689.5 250 100 50 40 700 Definition of MIN Radius for PIDs and SHIELD holes !!! NOT IN SCALE (but figures should be correct) TOF KL SW max radius 800

17. m.apollonioMICE Analysis meeting 23/1/200717 According to the defs given in previous slides these are the min radii (a) for the shield (to let every  pass) and (b) for the PIDs (to accept every  ) Within tolerances 1000x1000 mm 2 600x600 700x700 mm 2 Slightly out ? tolerances Is it a problem?

18. m.apollonioMICE Analysis meeting 23/1/200718 Wang-200-42 Z-downstream: shield-in shield-out SW TOF KL like having a 20 cm shorter SW calorimeter But only for the outer muons

19. m.apollonioMICE Analysis meeting 23/1/200719 conclusions the maximum radii for particles traversing MICE are propagated (from the max R in 3 different places) through the apparatus (TKs, ABS, RF) Considering several optics: min Radius (at fixed position z=-6150 mm) for the diffuser is defined: in order to have particles in the TKs it turn out Rd should be as large as possible (compatible with mechanical contraints) In any case RD=10 cm is too small ! min radii for downstream shield holes are computed upon the requirement of accepting every  from trackers min radii for PIDs are computed upon the requirement of having the maximal acceptance within the detector: this condition can be probably relaxed Real B field in the “shield area” should take into account real map. This is just an approximation whose purpose is giving some initial figures