UCLA group meeting 1/11

CSC update – a 2-week summaryCSC update – a 2-week summary

• Status of CMS at LHC: L=2*1032 reached 25-Oct-2010 (=the original goal for 2011) and

42 pb-1 collected by CMS• Standard Model remains unbroken…• Now running Pb-Pb collisions, 3.5 TeV/proton/beam (next slide)• Technical Stop now planned Dec. 6-Feb. 18• Running in 2012?

• CSC has been running well:• Oct. 27 water leak alarm on YE+1 found to be spurious (?)• Some HV trips during particular fills – beam conditions?

• Lowered HV settings for those channels, thereafter far fewer trips• RAT firmware “not there” for one crate… lower current

• Greg reloaded firmware• Heavy ion runs – not much different for CSC

UCLA group meeting 2/11

A Pb-Pb eventA Pb-Pb event

UCLA group meeting 3/11

…also……also…

• Alignment• Discrepancies between barrel (hardware) and endcap

(track-based), • Z mass shows signs of a possible twist in silicon

tracker

• Future• Lower HV when not in an active fill?• CLCT muonic timing?• Replace a lot of TMB fuses? Gold or silver?• CSCTF rate may be too high at L>10E33 (low-Pt muon

efficiency ~10%)

UCLA group meeting 4/11

Debriefing from U. Zurich WorkshopDebriefing from U. Zurich Workshop

• Practice talk for CSC Ops/DPG tomorrow

• Held Nov. 2-3, 2010• “Run Coordination” topic,

request was:•Critical look back at 2010

•Too many talks took a boring UN-critical look

•Look forward to 2011 issues•Too many talks ignored this

aspect

• Nonetheless a variety of issues came up that were relevant to CSC

UCLA group meeting 5/11

CSC Issues Noted by Greg - ICSC Issues Noted by Greg - I

• Run Coord. would like common name for subsystem expert on call

• CEO is a great acronym…

• CSC problem changing states “FSMStateError”

• Will be exercised during Technical Stop

• Out-of-Sync errors in FEDs:• Caused by data transmission error

DDUDCC• Causes errors a few times per month• Will NOT be fixed for quite a while (needs

new firmware) – grumbling ensued• (Will these increase with higher

luminosity??)

UCLA group meeting 6/11

CSC Issues Noted by Greg - IICSC Issues Noted by Greg - II

• HV trips lower voltages• Seems to have helped quite a bit

• Plan is to automate the whole procedure…

• Online computers getting old, have failure• During Technical Stop, the central computer group

plans to reinstall OS for every relevant computer

• Not the same as a hot-swap

• Plan to replace old computers only during long 2012 break

UCLA group meeting 7/11

CSC Issues Noted by Greg - IIICSC Issues Noted by Greg - III

• Simplify life of the CEO with the CSC Expert System

• Interest in this expressed by HCAL• Perhaps convergence at some

point? (E.g. already have DAQDoctor working for central DAQ)

• CSC-TF firmware stable for now, but needs performance improvements (next slide)…

• Also overlap region GMT qualities need a fresh look (efficiency drops due to lack of RPC)

Threshold Efficiency for CSCTF pT Assignment

1.2 < η < 2.1

• pT assignment efficiency decreases as pT threshold increases

• Significant efficiency at low pT will result in large rates

• Plan for Dec-Feb Technical stop: Use 2010 data to improve pT assignment LUT (in all eta regions)

Released result… http://indico.cern.ch/conferenceDisplay.py?confId=99228

A. Kropivnitskaya (UF)

UCLA group meeting 9/9

CSC Issues that Came Up - ICSC Issues that Came Up - I

• It is possible to imagine 5 fb-1 at 8 TeV in 2012

• Find or rule out the Higgs boson• <n>=11 pile-up events/Xing

• “Top-level” DQM plots for CSC need more thought

• Built-in reference histogram comparisons?

• HV computers are our oldest, not Quattorized

• We have a spare at B904• There is a plan to update them, but

probably not until 2012 shutdown

• Should DDU only notify FMM on sync loss, not other types of errors?

UCLA group meeting 10/9

CSC Issues that Came Up - IICSC Issues that Came Up - II

• 50 ns bunch spacing & beam halo• Upstream halo can appear in good collisions, but can

easily be removed by offline timing… • But harder if it came from next bunch 50ns later

• We don’t have a specific plan for HV reverse-voltage training at Pt. 5

• Is it too risky?

• Firmware tracking• Time to get serious is NOW (need to document 2010

conditions)• Under aegis of engineers or online software group?• Binaries and source code, but not “environment” for

compiling

UCLA group meeting 11/9

CSC Issues that Came Up - IIICSC Issues that Came Up - III

• Pixel re-syncs ~once/min at start of fills• Could we have problems that are masked by this?