1. TOF/ACC test Overview M. Yoshida Osaka Univ.

2. TOF / ACC in the prototype test For the prototype test in May, we will need PID: –TOF counter Distinguish  /  /p/e with 50ps time resolution in high magnetic field ~ 2kGauss –Long light guide to keep proper PMT gain Absolute momentum measurement for low momentum muons in PhaseII –Aerogel Cherenkov Counter (ACC) Distinguish  /  by thershold Distinguish  /e by photon yield –High photon yield is required Check the performance of TOF and ACC Survey low momentum beam (muon yield) –KEK-PS T577 from Feb.1 to Feb.7, 2005

3.  /  separation by TOF Assuming  upstream =50ps s downstream =60ps  TOF =sqrt(50^2+60^2)=78ps  3  separation @ 600MeV/c Momentum resolution ~10MeV/c @ 350MeV/c

4. Expected ACC light yield Momentum: 0.5GeV/c Refractive index: 1.03 p.e.

5. Setup (KEK-PS T577)

7. ⇒ σ(ref)=42.03ps σ(tof)=49.08ps Time resolution

8. PID by TOF and ACC  e 0.5Gev/c 0.6Gev/c ACC pulse height Time of flight  ~10%

9. Next talks TOF design & performance –  Atsushi Horikoshi ACC design & performance, and Beam property –  Ken’ichi Sakai