TRT ONO: Operation News & Overview

1. TRT ONO: Operation News & Overview A.Loginov, A.Romaniouk For the ATLAS TRT Collaboration TRT Days October 29 2013

2. Status: Active Gas • Leaks @ 2012 • Stress corrosion + Ozone • DQ didn’t suffer • All accessible leaks got fixed • Devil in details: inaccessible leaks survived… • Work ongoing to mitigate this effect • Better (remote/automated) active gas flow control • Be ready to use combination of Xe (default) and Ar (for the leaky channels) • TDR leak rate: 100l/day • Ozone studies: reduce Ozone concentration • Don’t want any new cracks causing new leaks… • Default strategy for Run 2 • As large TRT fraction as possible for as long as possible with Xe mixture • If we need to run with Ar • Good: Tracking doesn’t suffer. Bad: Transition radiation gets lost TRT Days/ID week, October 2013

3. Status: High Voltage • 2 issues in 2012: same origin • Lacquer all the contacts to prevent similar issues: done! • Have 3 spare crates (1 x USA15, 2 x SR1) • And a few spare HVM modules • Firmware upgraded, various tests done • Need to install filtering system to avoid dust… • …and to calibrate HV • =>things are well under control TRT Days/ID week, October 2013

4. Status: Detector Control System • Very successful operation in Run 1 • Quickly prepared tools for Xe/Ar combined running • Massive upgrades are ongoing for LS1 • As a part of general DCS upgrade (windows -> linux etc) • Development of TRT specific tools • Overall strategy for the LS1 upgrade • Fully reversible upgraded <-> old DCS • All the time most of TRT hardware is under control • Also will upgrade GGSS • Standard PCs, exchange of all existing internal PCI cards to internal ones, can replace straws if needed • All proposed HW components are linux/windows compatible • The core code of GGSS should run on linux/windows TRT Days/ID week, October 2013

5. Status: Data AcQuisition • DQ @ 99.8% in pp @ 2012 • Despite gas leaks and minor problems • Got a number of tolerable defects (TRT_BADGAS_01, TRT_BADGAS_02) • Number of dead channels Is stable • within declared 2.7% (2.4%) • Run 2 Challenge: 100kHz trigger rate @ high occupancy • HW and SW parts of the DAQ project are getting ready • Radiation damage • Studies ongoing (this includes work on calibration tools) • Many more details in Sarah’s talk after the coffee break TRT Days/ID week, October 2013

6. 2014 and beyond • 2014 Milestoneruns: • M1: Feb 17-21 (randomtrigger) • M2: March 31-April 4 (randomtrigger + FastOR + maybe RPC) • M3: May 19-23 (from M3: FastOR, RPC, Calotriggers etc) • M4: July 7-11 • M5: Sept 8-12 • M6: Oct 13-17 • TRT @ M2: • Integration in the new TDAQ infrastructure • High rate tests, different operation modes tests • TRT failure mode studies? • Fast OR tests and tuning • Test gas distribution efficiency (and active gas regulation studies?) • TRT shift crew should be available 24/7 TRT Days/ID week, October 2013

7. 2014 M-Runs TRT Days/ID week, October 2013

8. 2014 M-RunParticipation Taken from S. Zimmermann @ LS1-Weekly (last week)

9. 2014 and beyond TRT Days/ID week, October 2013

10. ATLAS: Run 2 • Many discussions on how to operate ATLAS • See the “ATLAS Post-LS1 Operation Workshop summary” https://edms.cern.ch/document/1317815/1 • Need to make sure things look good TRT-wise • Need to provide TRT feedback • Fewer shifters • More information to look at (muon system will be completed + IBL + etc) • Better tools / more uniformity (or more headache during the operation) • Updates of the CR layout, calibration procedures, shifters’ training etc etc etc • Will be (again and again) asking for inputs to make sure that TRT is properly taken care of by the shift crew TRT Days/ID week, October 2013

11. Summary • Run 1 was success • Thanks to all the expertise and dedication of the TRT team: the team made the TRT a great detector! • “great_trt” was chosen for the reason ;) • Will have things ready for the Run 2 • A lot of work has been done / remaining work will be done in the coming weeks/months! • => Many presentations today and tomorrow TRT Days/ID week, October 2013

12. Few backup slides TRT Days/ID week, October 2013

13. TRT DAQ in Run 2 • Goal: 100kHz trigger rate @ high occupancy • Bottlenecks: • Front End to ROD bandwidth • Changing from full readout mode (27 low threshold bits) to reduced mode (23 low threshold bits) increases trigger rate limit from 89 kHz to 105 kHz (ongoing activity) • Dropping last 4 LT bits – minimal impact on tracking (not losing the leading age) • ROD processing rate • Event processing time proportional to occupancy due to on-board compression • Solutions include: • Increasing clock speed from 80 MHz to 100 MHz on compression chip increases bandwidth • Hard-coding common words to decrease occupancy that compression chip must process • Applying validity gate on all words to decrease overall occupancy • ROD to ROS bandwidth • Extrapolation to high lumi indicates that this is not limiting factor • Optimization of compression table reduces load • Monitoring of fragment size in place TRT Days/ID week, October 2013

14. Other TRT DAQ Issues • Increasing number of automatic resyncs during stable beams at end of 2012 (order once per hour) • May be caused by power instabilities in VME crate which affect sensitive components on ROD • Crates will undergo upgrade to increase current limits on relevant lines • Maraton LV power supply upgrades (connector upgrade and internal wire replacement) • Rolling upgrade to be completed during LS1, currently on-schedule • Sufficient number of spares TRT Days/ID week, October 2013

15. Other TRT DAQ Issues • Increasing number of automatic resyncs during stable beams at end of 2012 (order once per hour) • May be caused by power instabilities in VME crate which affect sensitive components on ROD • Crates will undergo upgrade to increase current limits on relevant lines • Maraton LV power supply upgrades (connector upgrade and internal wire replacement) • Rolling upgrade to be completed during LS1, currently on-schedule • Sufficient number of spares TRT Days/ID week, October 2013

16. eFastOr • Upgrade the existing FastOr trigger • https://cds.cern.ch/record/1516518 • Physics motivation: HIP (monopole, Q-ball…) • Potential timeline TRT Days/ID week, October 2013

17. Active gas issues • Excellent work of TRT active gas team • Despite all the leaks, the DQ didn’t suffer • TDR specs: Xe leak @ 100 l/day • Before early 2012 the leaks were a few times smaller • By the end of 2012 we got ~200 l/day • Leaks • Stress corrosion enhanced by Ozone presence • Strategy discussions since few months, study insitu / repair during last few weeks • Repair work finished TRT Days/ID week, October 2013

18. Leaks Detector connector • Repaired whatever was accessible • Both EC Side C / Side A A1 crack along the pipe (PPF1 connector) PPF1 brackets TRT Days/ID week, October 2013

19. EC wheel type A connectivity Electronics Electronics PEEK pipes shown in pink Gas OUT Gas IN Gas manifold Gas manifold Straws/radiator Straws/radiator Places of stress Gas Gas TRT Days/ID week, October 2013

20. XevsAr: Tracking • Resolution (tracking @ Ar is not affected) • Run 218391: Ar/CO2/O2 @ 80/17/3, HV @ 1365 V • Barrel: 0.123 mm (Xe) / 0.131 mm (Ar) • EndCap: 0.123 (Xe) / 0.127 (Ar) TRT Days/ID week, October 2013

21. Active Gas System: Ar studies • Studies with both the TRT and at test stands • measurements of signal shapes for different gas mixtures and ASDBLR shaping options (report by X.Povedalink) • Main conclusion: afterpulses at 100 ns after the main pulse are observed if Xe shaping has to be used, more pronounced for high HV values • Different mixtures, HV settings (report by K.Vorobevlink) • Study stability, gas gain limitations etc TRT Days/ID week, October 2013

22. Active Gas System Plans • Possible to stabilize most leaks. Need to control 2 parameters: • gas flow in a leaking channel • Remote flow regulation? • pressure in the TRT outlet (pump inlet pressure) • Need 0.005 mbar accuracy (with the original requirement of 1 mbar) • precise pressure sensor • additional buffer for pressure sensor • pump input resistance regulation • cavern-USA pressure difference feedback to the pump operation • Ar mixture blow out setup • Have a temporary setup operating for the pPb running • Automate N2 removal (because of the TRT leak) TRT Days/ID week, October 2013

23. TRT Performance in Heavy Ion runs • Excellent performance even with extreme occupancies (plots taken from link) TRT Days/ID week, October 2013

24. TRT DCS: PCs, Systems and HW… A “simple” drawing TRT Days/ID week, October 2013

25. XevsAr Saga • Put Ar in few parts of the detector (both in barrel and EC) • Prepare tools / Learn from the operation / Save Xenon • Vary gas mixtures / HV settings to study operation • Studies with the TRT and on a test stand • Argon shaping issue • Mis-stuffed resistors in a fraction of EndCaps (and hence bit problems) • Under studies • Xe->Ar => electron ID is affected • Argon can be operated with larger gain than Xe • Electron Drift-time for Ar is shorter than Xe • Transition Radiation absorption down by ~10 compared to Xe • Need to understand the consequences TRT Days/ID week, October 2013

26. XevsAr Saga: PID • This is under study, but here are few points below • No TRT seeding hits for conversion finding => CPU time for conversion finding increases by a factor of 10 • Overall, back tracking is affected • High-PT electron trigger affected • Increase by 20-30% without HT hits information @ HLT • Jpsi -> ee trigger affected • Rates increase by a factor of 2 • So…many things to try • Find / repair the leaks @ EC • AND Cheaper Xenon (30% lower price) from the Russian supplier? • AND Optimize performance / study combined Xe / Ar operation effect on physics / etc TRT Days/ID week, October 2013

27. Leak Hunt and More: few Dates • 8-13 March • ID End-plate leak search (CO2) • 18 April – September • TRT gas leak repair work • Developing tools… • 18 February – November 2014 • Active gas racks test / modifications etc • Replacements ofMaratons • PP2 replacement/tests/repair TRT Days/ID week, October 2013