1. Study of the Spatial Resolution and Muon Tomographic Imaging Properties of Glass RPCs Qite Li Peking University

2. Knowledge is Power Sir Francis Bacon (1561-1626)

3. Nuclear Knowledge can be the Power of Peace Happiness Fear Frustration

4. ●Uranium 90% (HEU) ●Pu-239 93% (WGPu) ●26 kg HEU / 5kg WGPu ●11 cm / 6 cm box

6. Muon Tomography(MT) 2.3mrad 10mrad 20mrad ~1.1° ~GeV Muon 1/cm 2 /min waterFeW 10cm

7. MT Station Examples Los Alamos (2003): Drift Tubes Science and Global Security 16 (2008) 37–53 INFN : CMS Muon Barrel Chambers Nucl. Inst. and Meth. A 604 (2009) 738-746. FIT : Triple GEMs Nucl. Inst. and Meth. A 652 (2012) 16-20

8. Requirements of Detectors for MT Large Area (~1m 2 ) High Detction Efficiency (>90%) High Spatial Resolution (<1mm) Cost-effective

9. RPC Resistive Plate Chamber –R. Santonico(in 1980s) Large Area Good Time Solution ~1ns Acceptable Spatial Resolution –~1cm CMS Muon Trigger RPCs by PKU (2002)

10. -HV HV Graphite Resistive Plate Working Gas Resistive Plate Gruand Graphite Readout Strips RPC Brief View

11. Combination of RPC & Delay-line Readout 90% F134a+9% C 4 H 10 +1% SF 6 50ml/Min

12. Avalenche Signal General Properties: Signals Avalenche +Streamer Signal

13. General Properties: Detection Efficiency

14. -HV

15. Streamer Profile Sigma 7.4 ± 0.2mm Avalanche Profile Sigma 2.2 ± 0.1mm Simulation Profile Sigma 2.40mm

16. Spatial Resolution Measurement Residual Method ΔX=X 2 -(X 1 +X 3 )/2

17. Spatial Resolution of Glass RPCs

18. Uniformity -50mm~-25mm Res=0.99 mm -25mm~0mm Res=0.89 mm 0mm~25mm Res=0.82 mm 25mm~50mm Res=0.94 mm

19. X Y and T readout in ONE RPC

20. X axis 0.79 mm (FWHM) for one RPC Y axis 1.97 mm (FWHM) for one RPC Preliminary

21. MT Station with three 2D-Glass RPCs 12+2 channels RPC 1 RPC 2 RPC 3 Material

22. Imaging Result: Empty target Empty target Mean angle ~15 mrad –Position/Alignment error ~8 mrad –RPC box, framework ~10 mrad Preliminary

23. Imaging Result: Pb brick 1 Pb brick 1 15cm*5.5cm*3.5cm Preliminary

24. Imaging Result: Pb brick 2 Pb brick 2 24cm*7cm*6cm Preliminary

25. Conclusions Glass RPCs with LC Delay-line Readout –Simple structrue, stable performance –Efficiency 95~98% –Charge profile measurement <1mm(FWHM) in avalenche mode –Ideal detectors for MT MT Station using three 2D-Glass RPCs –Preliminary Test (detection area: 20cm*20cm) –Sensitive to ~cm Pb

26. MT station with 4 RPCs 3D Imaging Coming Soon

27. Thank You! Email: Liqt@pku.edu.cn Gmail: Liqt1985@gmail.com Supervisor: Prof. Yanlin Ye Email: yeyl@pku.edu.cn Peking University, China