TRT ONO: Operation News & Overview

TRT DaysOctober 29 2013

A.Loginov, A.RomanioukFor the ATLAS TRT Collaboration

TRT Days/ID week, October 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 Milestone runs:• M1: Feb 17-21 (random trigger)• M2: March 31-April 4 (random trigger + FastOR + maybe RPC)• M3: May 19-23 (from M3: FastOR, RPC, Calo triggers 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

8

2014 M-Run Participation

21 Oc 2013Taken from S. Zimmermann @ LS1-Weekly (last week)

M1 M2 M3 M4 M5 M6 PIX X1 X2 1 ready using events simulated at ROD level. 2assuming detector cold end of

MayIBL X1 X2 X2 1 ready using events simulated at ROD level. 2 assuming detector cold end of

maySCT X Needs detector cold for frontend, summer

TRT + + + + +LAR X Ready for M3, limited guarantee for online software. Definite participate in

M4, participate in M5 or M6, but possibly not bothTIL -- -- -- X Available from July, before busy with commissioning activitiesL1Calo X1 X2 -- X3 X4 X5 1Readout only. Trigger requires TIL, LAR. 2Best effort incl. some nMCMs

(trigger). 3 partial triggering, depending on CMX commissioning; 4 full legacy

triggering with completely upgraded hardware(nMCM, CMX) 5 introduce basic L1Topo triggerShutdown L1Calo during USA15 shielding wall (LS1 schedule: finish by March 20)

CSC X1 X2 1 Old RODs, side A only 2 New RODMDT X RPC X1 X2 ? X2 1 no operating gas, RPC L1 not guaranteed ready

2 part of the detector with correct gasTGC X1 1 no n-pentane, no triggering. n-pentane only after detector closedBCM X ALFA -- -- -- -- X (--) Detector not available before M5LUCID -- -- -- -- -- X Driven by det. reinstallation autumn 2014

TRT Days/ID week, October 2013 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• Repaired whatever was accessible– Both EC Side C / Side A

A1 crack along the pipe (PPF1 connector)

PPF1 brackets

Detector connector

19

Electronics

Gas manifold

Gas

Straws/radiator

Electronics

Gas manifold

Gas

Straws/radiator

Gas IN

Gas OUTPEEK pipes shown in pink

Places of stress

EC wheel type A connectivity

TRT Days/ID week, October 2013

TRT Days/ID week, October 2013 20

Xe vs Ar: 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.Poveda link)• 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.Vorobev link)• 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

Xe vs Ar 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

Xe vs Ar 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 of Maratons– PP2 replacement/tests/repair