1. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 1 Final design and plan for LMRPC production Outline: LMRPC structure Material Production procedure and QC Performance test Time schedule Wang Yi on behalf of Tsinghua and USTC Department of Engineering Physics,Tsinghua University

2. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 22 A large area of muon telescope detector (MTD) at mid-rapidity, allows for the detection of di-muon pairs from QGP thermal radiation, quarkonia, light vector mesons, possible correlations of quarks and gluons as resonances in QGP, and Drell- Yan production single muon from the semi- leptonic decays of heavy flavor hadrons advantages over electrons: no  conversion, much less Dalitz decay contribution, less affected by radiation losses in the detector materials, trigger capability in Au+Au trigger capability for low to high pT J/  in central Au+Au collisions excellent mass resolution, separate different upsilon states e-muon correlation to distinguish heavy flavor production from initial lepton pair production STAR Muon Telescope Detector

3. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 33 Concept of Design of the STAR-MTD A detector with long-MRPCs covers the whole iron bars and leave the gaps in- between uncovered. Acceptance: 45% at |  |<0.5 117 modules, 1404 readout strips, 2808 readout channels Long-MRPC detector technology, HPTDC electronics (same as STAR-TOF)                     

4. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 4 MTD requirements: Time resolution less than 100 ps, spatial resolution ~ 1 cm. The mechanics design must allow a convenient replacement of individual MTD box and access to the BEMC box. The system must be able to operate in the fringe field from 0.5 Tesla STAR magnet field. The system must operate at low noise rate. The total noise rate should be less than 0.5 M Hz, 1 Hz/cm 2. The system must be safe, meet all BNL safely requirements. The system must not impair the performance of other STAR detectors. MTD System Requirement

5. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 5 Structure of LMRPC module For assuring the stable performance, we will compare the performance between 5 and 6 gaps modules.

6. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 6 Structure of LMRPC module

7. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 7 Performance of LMRPC Cosmic ray testBeam test Time resolution ~ 70ps, efficiency> 95%

8. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 8 94%Freon/5%iso-butane/1% SF6 95%Freon/5%iso-butane Noise < 0.6 Hz/cm^2 @ 7200V Noise < 0.4 Hz/cm^2 @ 7200V Noise level @different gas mixture LMRPC meets the MTD requirement!

9. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 9 MaterialType and manufacturerDimension (mm)Tolerance (mm)Quantity Outer glassBeijing 890  559  1.1 ±0.5, ±0.5,±0.02 2 Inner glassBejing 870  549  0.7 ±0.5, ±0.5, ±0.02 5 Graphite electrodeColloidal graphite SR~4 Mohm/ 888×557×0.1-0.52 Mylar filmDupont Corp.895×564×0.15±0.12 Honeycomb boardAoxing Corp.890×559×10±1.0, ±1.02 PCBShengYi Corp. G10 915×580×0.9 12strips, 38×870/strip ±0.52 L-shaped and cylinder supporter Weishi Corp. Polycarbonate height:4.8-0.0512 Nylon wireJapanDiameter 0.25±0.005 RTVCAF4, France HV lead 15kV, USA60cm±12 Signal lead34 ribbon cable, USA60cm±14 The materials for one LMRPC module

10. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University Chinese LMRPC production The LMRPC production is the same as STAR-TOF MRPC production, we have two production sites in China. Tsinghua University (60%) University of Science and Technology of China (40%) Facilities and tools ensure quality. Each site with QA and testing facility. Web-based module-data-base accessible at the assembly sites. 10

11. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 11 1/23/4 5/6 7/8 9/1011/121/2 3/4 5/67/8 9/10 11/12 Plan 20112012 Start 20 LMRPCs 40 LMRPCs 60 LMRPCs 80 LMRPCs 100 LMRPCs 115 LMRPCs LMRPC manufacture milestones 11 VECC will produce 10% (15 ) modules

12. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 12 Inner glass outer glass MylarHoneycomb board PCBGraphiteNylon wire … Material procurement Check Electrode assembly Yes LMRPC assembly Check distance Between PCB Solder signal cable Yes No Check continuity No Final check Test amplitude and time Label Yes No Procedures of construction and QC

13. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 13 Quality control on the material Glass – Measure the dimensions – Check the surface quality Pcb – Dimensions, – the scratch on the strips Honeycomb – Dimensions, surface quality Mylar foil: thickness, holes Fishing line – Dimension check of each coil Support block: thickness Material with faults will be returned back to factory.

14. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 14 HV cables and signal connection Rice and UT Austin will provide us HV and signal cables

15. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 15 MRPC put in box Exercise time: 10 hours HV: ± 7200V Measure current & noise rate Measure QDC & TDC 24×3 hours Flushing with gas 48 hours, 100ml/min LMRPC Testing Procedure For the first batch of LMRPC modules (about 20 modules), 100% strips will be tested for efficiency and time resolution. Later, 33% strips will be tested.

16. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University NominalMinimumMaximum Length 915mm914.2mm915.8mm Width 580mm579.2mm580.8mm Thickness 30mm28.5mm31.5mm LMRPC mechanical specifications 16

17. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University Testing conditionsSpecifications Working gas: 95% F134A+5% iso-butane Leakage current: < 40 nA HV: 14.4kVNoise rate: < 1Hz/cm 2 FEE threshold: 30mVEfficiency : > 90% Timing resolution < 120 ps for 90% strips MRPC performance requirement 17

18. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 18 Time schedule 2011.4 – 2011.6  finalizing the design Design modules with 5 and 6 gaps, test performance, detailed comparison. Make a conclusion on the performance of different structure with/without glue. Help VECC to establish test system, production tools and some materials… Module production: 2011.6 – 2011.12  20% 2012.1 – 2012.6  40% 2012.7 – 2012.12  40%

19. STAR-MTD workshop@USTC, March 30 th -April 1 th, 2011 Wang Yi, Tsinghua University 19