1. KM2A MD prototypes xiao gang 2011.2.18

2. introduction simulation Prototypes conclusion

3. introduction 1209 MDs spacing 30m triangle layout tank: area:36 m^2 Diameter: ~7m Height: 1.2m Dirt hillock: 2.5m

4. Simulation: select the WaterAbsLength(maxReflectivity 97.5%) maxWaterAbsLength ： 10m maxWaterAbsLength ： 20m maxWaterAbsLength ： 30m maxWaterAbsLength ： 50m

5. maxReflectivity ： 90% maxWaterAbsLength ： 30m Simulation: select the maxReflectivity

6. maxReflectivity ： 97.5% maxWaterAbsLength ： 30m Gamma @100 Mev, no shielding layer

7. maxReflectivity ： 97.5% maxWaterAbsLength ： 30m

8. Single particle resolution vs. water depth Single particle resolution

9. Punching-through

10. Dirt thickness Muon MPV Detect efficiency (0.5 mpv) Gamma mean Punching through (0.5 mpv) 0.5 m19.0784.02%0.60281.4584% 1 m19.1285.44%0.11640.2303% 1.5 m18.9684.96 %0.020310.0291% 2 m18.7283.62 %0.0034210.0025% 2.5 m18.6982.04 %0.0006560.0007% 3 m18.5975.20 %8e-50.0001%

11. Simulation conclusion: The length of tank>1.2m the thickness of dirt> 2.5m Reflectivity>97.5% WaterAbsLength>30m

12. Experiment in lab scintillator Small bag made of 2 layers, the inner is tyvek, the outer layer is TPU. 72cm 1.2m

16. prototypes dirt hillock concrete tank

17. prototypes: concrete tank

18. tyvek LDPE (low-density polyethylene) HDPE (high-density polyethylene) prototypes: plastic bag nuts sealed with the disk Stainless steel disk adhered on the bag PMMA cover adhered between the steel disk and the bag inletoutlet

19. prototypes: PMT and bag’s assembly transparent cover PE chimney Plastic pipe for installing the PMT Steel disk Cone nail for locating PMT hatchcover

20. Prototype: water quality Water –processing: Filter 、 UV disinfection 、 Soften 、 eliminate chlorine steriliration and cleaning of the bag airproof of the bag

21. conclusion The experiment of Small tank is ongoing The prototypes will complete in a half year

22. thanks