1. Another Conceptional Design of Veto Daya Bay Phone Meeting Changgen Yang 2006/03/01

2. Veto Detectors Water Buffer Cherenkov Detector Muon tracker: 1.RPC; 2.Plastic Scintillator; 3.LS; 4.Cherenkov Tank

3. Water tank, a real example

4. Photo-electron measurement

5. x z 15m x tank ; 1 PMT on each end; Size: 1x1x15m^3 y tank ; 1 PMT on each end; Size: 1x1x15m^3 3 layers of RPC/Scint. to guarantee high eff. 2m water container; passive shield Access to the central detector 20cm of water above the top of central detector to isolate the radon background (central detector -20cm below “level –1”) Level 0 Level -1

9. Comments Same technology, water Cerenkov detection, are used as water buffer Cherenkov detector and water tank detector (tracker); The water are connected so that no environmental effect; 200MeV/m energy deposition for muon while the background energy is normally less than 2.5MeV; but not good spatial resolution; Access to do calibration is now easier, but on the other hand, the deployment of the top shielding and detectors getting harder when swapping central detectors.