4 th workshop on alice installation and commissioning january 16 th & 17 th, cern muon tracking...
TRANSCRIPT
4th Workshop on ALICE Installation and Commissioning
January 16th & 17th , CERN
Muon Tracking(MUON_TRK, MCH, MTRK)
Conclusion of the first ALICE COSMIC run in December 2007.
Status of Hardware during Run
Dimuon Forward Spectrometer (DFS) Tracking Chambers :5 stations, each station has 2 detection planes or chambers1 chamber/plane gives an (x,y) coordinates
μ+
μ-
primary vertex
ZY
X
Station 1Station 2
3
4 5
read out during the december cosmic run.
Status of Hardware during Run
Dimuon Forward Spectrometer (DFS) Tracking Chambers :5 stations, each station has 2 detection planes or chambers1 chamber/plane gives an (x,y) coordinates
During the december cosmic run :almost everything is installed (but local commissioning is not finished yet) 1/5 of the DFS was powered
• Full Station 1 most of the time• part of Station 1 + part of Station 2 for the “2 LDC in global” test
no particular issues • air cooling (St1 and St2 is very stable), temperatures look fine• power ok (a few trips have been seen on HV and LV)• our last day (Tuesday 18th) was perfectly stable !
DAQ
No real DAQ issues :compliance with DAQ global achievedreally stable
Readout times (in 0-suppressed mode after taking pedestal runs, threshold calculation with a DA included in our rpm, etc… = conditions of real data taking ):
Trigger 4 kHz Busy 307 us Readout rate 2050Trigger 40 kHz Busy 485 us Readout rate 2050Trigger 400 kHz Busy 496 us Readout rate 2050Trigger 4 MHz Busy 497 us Readout rate 2050Trigger 40 MHz Busy 497 us Readout rate 2050
Readout rate is slower than expected (lab measurements gave busy ~ 220 μs) : looking for possible explanation
→ saturating the buffer slows down the readout (algorithm scan through a lot of events in the DSP memory)in normal data taking mode, an “open” muon trigger (no pT cut) will not be greater than 5KHz.
DCS/ECS/Trigger/HLT
DCS in very good shape :final state machine for low & high voltage works temperatures, gas flow is monitored
ECS :scripts are ready (close to final) and working (tested during run)automatic generation of command depending on which DDL/equipId are declared in DATE
Connection DCS-ECS (?) is not done yet
Trigger : first days have been painful… but it finally worked we played at “you’re busy; not we’re not ; yes you are ; etc…” along with trigger people and other subsystem ;-)
HLT : some global run were taken with HLT ; is it ok ?
Online Monitoring/Offline
Online Monitoring :MOOD for muon_trk is in very good shape
pedestal and gains visualizationsome global histograms (pad occupancy, hit map, errors)
Data from gdc have been monitored during run in global and …
That’s clearly a hit
Online Monitoring/Offline
Data Storage :data are on CASTOR and some ESD are produced
Data Quality Checks :?? Is it about QA histograms…?
COSMIC Data, Analysis Results
Raw data quality, event displays, Calibration results, Alignment results,Data reconstruction (ESD)Data analysis, First performance estimates i.e. signal/noise, tracks etc.
All this is ongoing, but no results so far… calibration runs have been taken pedestal runs show nominal/expected noisegms doesn’t seem to increase noise when runningESD are not analyzed yet ; we will probably reconstruct a few clusters (give an idea on clusters size, charge and S/N )
Hardware/Software Status for February Run + Goals
February Run : Full station 1 (as in december)Full station 2 (1/4 was successfully included in global in december)1 DDL from station either 3, 4 or 5
Goals :Pedestal/noise : done with the DA (committed in AliRoot) calibration : done running with 0-suppression : donealignment and tracks : needs tracks ! (and all the stations + survey)
Mostly the february run will be useful for testing the stability and training people. Some software work is needed as well to test and to finalize pieces of software (calibration, ECS scripts).
Action to Completion
Station 1 : ready for beam (dead channels ? but <<1%, all HV ok) Station 2 : ready for beam (to be confirmed this week)Station 3 : finishing the local commissioningStation 4 : finishing the local commissioningStation 5 : finishing the local commissioning
can not be stopped during the 5 weeks of the feb. cosmic run !
Conclusion
• Very good behavior of St1 : Cathode Pad Chambers works ;-)• Readout (CROCUS) is compliant with DATE and Trigger patterns handling is fine (L1/2 reject are implemented and tested in lab)
1 LDC fully loaded okand going to 2 LDC (partially loaded) was straightforward
→ including more should not be a problem (parallel treatment)• software for data taking (DA, ECS scripts, MOOD) is in very good shape• offline is working on the data ; pedestals runs are in OCDB and look fine
Visualization of a pedestal runin the OCDB.(L.Aphecetche)
Muon_trk questions
•Standalone runs with CTP emulator : will it possible to have an “all.seq” that include an sod+l2a+eod ? (without loading the 3 seq)
•What about documentation for shifters : ACR machines are disconnected from outside world. Everything should be done locally…
• ksnapshot + “openoffice, or anything else convenient”