1. CMS RESISTIVE PLATE CHAMBERS Lecce, 25 September 2003 Content Barrel single/double gap production and QC Barrel chamber production and QC Barrel production and installation schedule Aging test Extended documentation on each item can be found at http://www.ba.infn.it/~iaselli/annual_review_2003/

2. INFN Gruppo I Lecce, 25 September 2003 Introduction CMS RPC group G. Iaselli GT HT Bari Pavia Introduction Sofia The sites involved in the RPC construction are: gap production General Tecnica double-gap prod General Tecnica chamber assembling Bari, Sofia*, GT and HT** chamber test Bari, Sofia* and Pavia*** * from the 2004 ** from june 2003

3. SG and DG validation flow-chart DG assembled by GT Gas leakage test Control the gap bubbles in 30 s Bring the DG at 9500V and measure the current: reject if I > 5 A Bring the DG at 9500V and measure the current: reject if I > 5 A 2 SG validated by QC3 SG coupling INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli SG assembled by GT Gas leakage test Overpressure test Control the gap bubbles in 30 s Reach an inside overpressure of 20 mbar: check if spacers or frame detach Reach an inside overpressure of 20 mbar: check if spacers or frame detach GT connects the HV wire.The SG type is assigned Bring the SG at 9500V and measure the current: reject if I > 5 A Bring the SG at 9500V and measure the current: reject if I > 5 A

4. SG Rejected/Accepted vs. SG_ID The gluing crisis Rejection is slowing decreasing... SG are better quality now INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

5. SG Test Rejections HV failures distributed (significantly?) more frequently in the first SG Types produced: RB3 and RB1 HV test INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

6. SG Current distributions From Jan 15th, 2003 on, HV tests are performed up to 9500V, with a 96.5% C 2 H 2 F 4 /3.5% iso-C 4 H 10 gas mixture (*) From Jan 15th, 2003 on, HV tests are performed up to 9500V, with a 96.5% C 2 H 2 F 4 /3.5% iso-C 4 H 10 gas mixture (*) be as close as possible to real operating conditions Some of the older SG retested *Before Jan 2002 HV test were performed in pure C 2 H 2 F 4 up to 8 kV INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

7. SG Rejected/Accepted per type INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

8. SG Breakdown overpressures Warning: data on breakdown overpressures available only from SG 522 on The first peak is mainly due to SG presenting spacers already detached at the beginning of the test... When opened, sometimes, they presented small or missing glue on them. INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

9. SG Production Improvement Comparison between production of the same kind of SG in different periods INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

10. DG Production Status INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

11. DG: Problems and Improvements Discharges: in some DG, a discharge between the gap edge and the copper ground plane has been found (mostly on the side were solderings with the termination resistors are made). This was evident at a later stage, when DG had already been included in CH. From the production of the RB2 on, an additional C made of PET has been added; some of the older DG have been modified Average current absorbed by a SG (in DG) before PET: 2.32 µA @ 8 kV Average current absorbed by a SG (in DG) after PET: 0.83 µA @ 8 kV INFN Gruppo I Lecce, 25 September 2003 Single/Double Gap Production and QC CMS RPC group G. Iaselli

12. Chamber production status 20 RB1 chambers have to be modified (11 already modified at HT) See later for the problem found 20 chambers ready to be tested 4 chambers under test at PAVIA Assembled chambers Tested chambers INFN Gruppo I Lecce, 25 September 2003 chamber Production and QC CMS RPC group G. Iaselli HT and Pavia in operation

13. QA/QC at assembly and test sites Double gaps inventory Cooling system testGas flow test LV system test Kapton-FEB connectivity test DB update HV test: I vs HV I vs time Noise rate strip by strip QC during assembly Check list filling assembly QC after assembly INFN Gruppo I Lecce, 25 September 2003 chamber Production and QC CMS RPC group G. Iaselli HV connector mounting DB update Detector control I vs. HV I vs. time Single rate vs. HV (strip by strip) T, P, Humidity mon. Cosmic test Efficiency vs. HV: - single gap - double gap Cluster size vs. Hv Local efficiency with tracking Chamber performances Go to CERN REJECTED ACCEPTED

14. REJECTED First 7 chambers assembled at HT No SF 6 in gas mixture INFN Gruppo I Lecce, 25 September 2003 Chamber production and QC CMS RPC group G. Iaselli Current: summary Dark current distribution at at 9400 V. rejected accepted

15. Efficiency: summary HV at maximum efficiency Lower efficiency due to systematic Effects. INFN Gruppo I Lecce, 25 September 2003 Chamber production and QC CMS RPC group G. Iaselli

16. Noise: summary accepted rejected INFN Gruppo I Lecce, 25 September 2003 Chamber production and QC CMS RPC group G. Iaselli

17. Cluster: summary INFN Gruppo I Lecce, 25 September 2003 Chamber production and QC CMS RPC group G. Iaselli

18. Chamber stability Monitor of the Dark current for several days DW UP INFN Gruppo I Lecce, 25 September 2003 Chamber production and QC CMS RPC group G. Iaselli

19. Final tests at ISR Accepted chambers are sent to CERN and tested again at ISR. I vs HV I vs time data taking with cosmics (work in progress) About 70 chambers at ISR under test INFN Gruppo I Lecce, 25 September 2003 Chamber production and QC CMS RPC group G. Iaselli

20. The new production schema is based on the following assumptions: -------------------------------------------------------------------------------------------- ITEM200320042005 -------------------------------------------------------------------------------------------- gap production rate3/day 4/day5/day double-gap prod. rate*6-8/week8/week 10/week chamber prod rate**2-3/week 4/week 5/week chamber test rate***10/2weeks10-5/2weeks 10-5/2weeks * 6 bigaps/week if GT is assembling chambers too; 8 bigaps/week if not ** GT 2 chambers/week; Bari, Sofia and HT 4 chambers/week *** Bari 10 chambers/2weeks; Pavia and Sofia 5 chambers/2weeks phase I (from October 2003 to April 2004): 24 sectors 186 chambers 396 bigaps 792 gaps phase II (from May 2004 to December 2004): 13 sectors 109 chambers 248 bigaps 608 gaps phase III (from January 2005 to June 2005): 13 sectors 109 chambers 248 bigaps 608 gaps phase IV (from July 2005 to April 2005): 10 sectors 80 chambers 179 bigaps 438 gaps Production scheme and rate INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

21. Gap production INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

22. Double gap production INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

23. Chamber production INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

24. Chamber production per site INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

25. Critical path Installation sequence INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

26. What is ready INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

27. What is ready RB2, RB3 YB+2 bottom Ready RB2, RB3 YB+1 bottom Ready RB2, RB3 YB-1 sec 8-9 Ready RB3, RB2 YB0 bottom November 03 RB1 YB0 bottom Dicember 03 RB1 YB+1 bottom March 04 RB1 YB+2 bottom March 04 RB3 YB-2 sec 8-9 Ready RB2 YB-2 sec 8-9 October 03 RB1 YB-2 sec 8-9 March 04 RB1 YB-1 sec 8-9 March 04 RB4 YB0 sec 10 February 04 RB4 YB+1 sec 10 February 04 RB4 YB+2 sec 10 February 04 RB4 YB0 sec 9,11 March 04 RB4 YB+1 sec 9,11 March 04 RB4 YB+2 sec 9,11 March 04 INFN Gruppo I Lecce, 25 September 2003 Production and installatin schedule CMS RPC group G. Iaselli

28. Two different systems under test: High statistics test with small single gap chambers Test of production chambers (RB1s) Aim of the aging tests Test the RPC under high gamma irradiation with and without the muon beam and monitor the performance for a collected charge equivalent to 10 years of operation at LHC condition Operation conditions in CMS Barrel Rate: 30 Hz/cm 2 (safety factor included) Average total charge: 30 pC Effective operation time: 5x10 7 s (10 LHC years) Operation conditions in CMS Barrel Rate: 30 Hz/cm 2 (safety factor included) Average total charge: 30 pC Effective operation time: 5x10 7 s (10 LHC years) The total expected charge is 5 10 -2 C/cm 2 LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli

29. down forw Integrated charge Accumulated charge by small gaps Old gaps : > 10 years LHC equivalent reached in the OLD gaps New gaps: ~ 10 year LHC equivalent LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli Chamber 25 0.028 Accumulated charge by the two RB1 Chamber 26 up forw 0.025

30. Performance of small gaps Ch 3 A slightly increase of operation voltage with source ON & Off V eff90% (Source On) - V eff90% (Source Off) A slightly increase of DV during the time HV constant = 10. kV Ch B LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli

31. Test with water on RPC #9 Motivation: Possibile increase of the bakelite resistivity due to the high gas flux Since May until Sept: No gamma irradiation High gas flux rate (3 l/hour) 6 gas change/hour!!! Since Sept. up to now: wet mixture Iincrease of rate with wet mixture Full efficiency with source restored LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli

32. Efficiency @ 9200V 9 Sept. Source OFF Performance of RB1s cosmic beam 29 June LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli 9 Sept. 29 June Abs 1 beam

33. On 9 September the chambers were closer to the source 9 Sept about 800 Hz/cm 2 29 June about 200 Hz/cm 2 Performances of RB1s Efficiency (%) 9 Sept. abs10 abs2 abs1 Off LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli

34. Minimize the effort at GIF and concentrate on gas issues. Continue aging with the gas close loop system now in in operation at GIF. Study the effectiveness of the filters to absorb all the impurities. Optimise the following parameters versus impurities and chambers performance: -) percentage of gas recirculation -) gas flow rate -) percentage of humidity in the mixture Future plans LHCC comprehensive review CERN 23 September 2003 Aging tests CMS RPC group G. Iaselli

35. Conclusions INFN Gruppo I Lecce, 25 September 2003 Conclusion CMS RPC group G. Iaselli Barrel SG and DG production is going well and on schedule Barrel chamber production almost on schedule. New assembly sites and test sites operational. GIF test on the way. Satisfactory results so far. Worst is coming!! Manpower to run in parallel assembly/test sites, ISR and GIF may not be available.