1. Jun 27, 2005S. Kahn -- Ckov1 Simulation 1 Ckov1 Simulation and Performance Steve Kahn June 27, 2005 MICE Collaboration PID Meeting

2. Jun 27, 2005 S. Kahn -- Ckov1 Simulation2 Energy Loss for a Typical Muon Traversing the Cooling Channel  A typical muon will loose 35 MeV of KE from entering TOF0 to leaving the upstream SciFi detector (see table). There should be 10 MeV loss for each TOF station (5 cm Scintillator) and 10 MeV for 7.6 mm Pb Diffuser. The energy loss from Ckov1 radiator to upstream SciFi detector is only ~ 25 MeV

3. Jun 27, 2005 S. Kahn -- Ckov1 Simulation3 Upstream Cherenkov System  Upstream Ckov C 6 F 14 radiator with n=1.25 4 PMTs 2 on top, 2 on bottom. Cherenkov thresholds: 0.7 MeV for electrons 140 MeV for muons 190 MeV for pions

4. Jun 27, 2005 S. Kahn -- Ckov1 Simulation4 Cherenkov Threshold Effect The number of Č photons generated by the passage of a charged particle through the radiator is

5. Jun 27, 2005 S. Kahn -- Ckov1 Simulation5 Simulation Running Conditions  The beam contamination has the same momentum distribution as the muons. The relative number of PE from  and  now have meaning. The initial sample has 50%  and 50% . Events are generated just before Tof0 (-15750 mm) with  x =  y =50 mm  x’ =  y’ =25 mr  Samples with mono-chromatic momentum are run 180, 200, 220, 240, 260 MeV/c samples.

6. Jun 27, 2005 S. Kahn -- Ckov1 Simulation6  c Generated by Traversing  /  180 MeV/c200 MeV/c 220 MeV/c240 MeV/c

7. Jun 27, 2005 S. Kahn -- Ckov1 Simulation7 260 MeV/c:  c Generated by Traversing  260 MeV/c

8. Jun 27, 2005 S. Kahn -- Ckov1 Simulation8 Photon Generation in the Cherenkov Detectors  For each track that crosses the radiator with a velocity above threshold a number of photons are generated proportional to the deposited energy.  We currently do not use the Cherenkov photon facility in Geant4. There is some question as to how well it works with reflective surfaces.  Imaginary photons are generated in a cone (at the č angle) around the particle direction.  Since all mirrors are at 45º w.r.t. the beam direction, we can position the PMTs on an imaginary plane. The č photons that intercept the PMT circles are “seen”. Note that Ckov1 has an angle of 53°. The circles should be ellipses. This has not yet been taken into account  Note that in Ckov 1 we are dealing with only 4 PMTS.

9. Jun 27, 2005 S. Kahn -- Ckov1 Simulation9 PE Seen in PMTs from  /  180 MeV/c200 MeV/c 220 MeV/c 240 MeV/c

10. Jun 27, 2005 S. Kahn -- Ckov1 Simulation10 260 MeV/c: PE Seen in PMTs from 

11. Jun 27, 2005 S. Kahn -- Ckov1 Simulation11  c generated proportional to sin 2  c Cone radius proportional to tan  c

12. Jun 27, 2005 S. Kahn -- Ckov1 Simulation12 What Other Radiators Are Available? RadiatorIndex of Refraction Muon Threshold Pion Threshold C 6 F 14 1.25140 MeV/c185 MeV/c Liquid N 2 1.205156 MeV/c208 MeV/c Liquid H 2 1.128202 MeV/c267 MeV/c Liquid Ne1.092240 MeV/c318 MeV/c Aerogels<1.08>257MeV/c>341MeV/c

13. Jun 27, 2005 S. Kahn -- Ckov1 Simulation13 Using Liquid N 2 Radiator

14. Jun 27, 2005 S. Kahn -- Ckov1 Simulation14 Liquid N 2 Radiator

15. Jun 27, 2005 S. Kahn -- Ckov1 Simulation15 Ckov1 Efficiency as a Function of Energy P  =180 MeV/c P  =240 MeV/c

16. Jun 27, 2005 S. Kahn -- Ckov1 Simulation16 Conclusion  C 6 F 14 with n=1.25 is not the optimum radiator for  /  separation in the desired momentum range, particularly for p   240 MeV/c in the channel.  The problem is that we would like n=1.16 to handle the desired momentum range with a single radiator. There are no radiators in that range.