5 th Workshop on ALICE Installation and Commissioning April 1 rst & 3 rd, CERN Muon Tracking (MCH) Conclusion of the February/March 08 ALICE COSMIC run.

Status of Hardware during Run Dimuon Forward Spectrometer (DFS) Tracking Chambers : 5 stations, each station has 2 detection planes or chambers 1 chamber/plane gives an (x,y) coordinates μ+μ+ μ-μ- primary vertex Z Y X Station 1 Station read out during the cosmic run. [Chamber 5] and for the first time, triggered by the muon trigger

Status of Hardware during Run Dimuon Forward Spectrometer (DFS) Tracking Chambers : 5 stations, each station has 2 detection planes or chambers 1 chamber/plane gives an (x,y) coordinates During the Feb/Mar cosmic run : everything was installed (except chamber 6, inside the magnet) and local commissioning (St 4 &5) was being done in parallel 2/5 of the DFS was powered Station 1 and 2 part of Station 3 (chamber 5) has been readout as well (max configuration : 3 LDC, 11 DDL) air cooling (St1 and St2 is very stable), temperatures look fine still some HV trips ! Never seen during previous tests → How sure are we of the gas quality ?

Data Taking Two periods of data taking : Acorde trigger (~80Hz) : from run to run very large number of events ; should be enough to check clustering algorithms. Tracks have a (too) large angle and offer limited interest Muon Trigger (~80mHz): from run to run a total number of events is around 8840 (∑ runs requested to be reconstructed) a first analysis shows shower events are dominant but a few horizontal tracks → very interesting to look at

DAQ No real DAQ issues : compliance with DAQ achieved really stable : 1 run of 10 7 events with 40MHz 2 runs of events with 40MHz 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 ): Readout rate is slower than expected (lab measurements gave busy ~ 220 μs). Well aware of the problem ; need time to be investigated since other tasks have higher priority. Goal is to decrease deadtime (well) below 200 μs. Entry in the loogbook RunBusyL2a_StrobeTimeDeadtime (us)Busy (%) DAQ rate (Hz) CheckPulser rate (Hz) ,9992,03% ,692,83%1010, ,1028,31%10200, ,0859,22%20450, ,2173,76%23500, ,3069,66%20500, ,7893,40%13300, ,2499,96%13351,

DCS/ECS/Trigger/HLT DCS : final state machine for low & high voltage works temperatures, gas flow is monitored (still some improvements -alarms handing and interlocks- to be done) ECS : scripts are ready and working. No issues. + Bridge tested and OK Trigger : Some problems but is it really the trigger ? Clearly some busy problem when run stops “unexpectedly” at DAQ level. It happened a lot during the first week (w9) but not a single problem during w10 (in the Alice_multi partition with MTR & V0). (we didn’t forgot the trigger questionnaire) HLT : We all have seen some results ! Haven’t we ?

HLT Monitoring/Analysis HLT readout on the ldc : 1- subtract pedestal (on the 0-supp data) 2- apply a rough cut (all digits > 10 ADC) 3- scan interesting events 4- display the results on the ACR big screen All plots available at :

HLT Monitoring/Analysis Fired pads isolated with a sharp 10 ADC cut on 0-suppressed and pedestal substracted data.

HLT Monitoring/Analysis A straight line passing the fired pads points clearly to ACORDE.

HLT Monitoring/Analysis A straight line passing the fired pads/strip points towards the center of ALICE (muon trigger decision algorithm)

HLT Monitoring/Analysis

Online Monitoring/Offline Online Monitoring : All with MOOD pedestal, noise and gains visualization some global histograms (pad occupancy, hit map, errors) Data from gdc have been monitored during run in global New Mchview tool : Not online but can read all information at the OCDB level histogram all quantities for any granularity (from single pad to full chamber)

Online Monitoring/Offline MCHVIEW : Analysis of calibration run for St. 1 and 2 Using the file from the OCDB (copied from alien) → Full chain is working from the ECS calibration script up to analysis

Online Monitoring/Offline MOOD : Online display of run Fired pads on chamber 4

Online Monitoring/Offline MOOD : Online display of run Fired pads on chamber 3

Online Monitoring/Offline MOOD : Online display of run Fired pads on chamber 2

Online Monitoring/Offline MOOD : Online display of run Fired pads on chamber 1 Mapping problem now fixed.

Online Monitoring/Offline ALIEVE : offline display of the same event (126) run from reconstructed digits. From offline muon clustering, 5 hits are reconstructed : ************************************************************* * Row * ch * charge * size * absPosX * absPosY * absPosZ * ************************************************************* * 1742 * 0 * * 5 * * * * * 1743 * 0 * * 6 * * * * * 1744 * 1 * * 10 * * * * * 1745 * 2 * * 3 * * * -673 * * 1746 * 2 * * 3 * * * -673 * * 1752 * 3 * * 9 * * * -692 * *************************************************************

Online Monitoring/Offline Data Storage : data are on CASTOR AliRoot reconstruction has been run on a sample of data (by muon “offline shifters); 13 runs → MUON.digits available on alien Data Quality Checks : QA/AMORE is a work in progress - To do List for QA (Mar08) To complete QA classes with: From raw-data: - Hit distribution per chamber (TH1 with the chamber number in the horizontal axes); - Hit distribution per detection element (TH1 with the DE number in the horizontal axes) - Hit distribution per buspatch (10 TH2 (one per chamber) with the buspatch geographical distribution (as in mchview) From recpoint: - Trigger efficiency plots (Diego) - but now in analysis task - Check of the trigger code (Who?) - Trigger scaler values(Diego) - Strip hit distribution (4 TH2 one per chamber with the strip distribution)(Diego) - Local board hit distribution (1 TH2 with the local reponse of each local board)(Diego) From ESD - p, pt, y distribution - already in place - track multiplicity = number of tracks per event (somehow related to tracking efficiency) - track cluster multiplicity distribution = number of clusters per track (somehow related to clustering efficiency); - Multiplicity of clusters per chamber (10 TH1); - Multiplicity of cluster per detection element (144 TH1); - Charge of the cluster per chamber (10 TH1); - Charge of cluster per detection element (144 TH1); - Normalized Chi2 of the track (somehow related to tracking quality) - Distance between clusters and track (somehow related to clustering quality and alignment accuracy) - Number of track matching trigger (somehow related to tracker/trigger efficiency) NEW Christian, Philippe P., Diego

COSMIC Data, Analysis Results AliEve display the MUON digit from reconstructed data For the moment, clusters are reconstructed afterwards: see the clustering algorithm at work on real data implementing trigger selection look for horizontal tracks All pedestal runs (so far) show nominal/expected noise. Magnets (dipole+L3) effect on measured noise : comparison of runs – Relative noise difference : mean=0.04 ADC and σ=0.07 (nominal noise is 1.1 adc) compatible with single channel noise fluctuations.

Hardware/Software Status for next cosmic run + Goals To do for next Run : Some electronics to be fixed on Station 1 & 2 Some software to be installed (related with the trigger/busy) → already scheduled for w15 (along with DAQ/Trigger test) Some work on the interlocks needs to be done (DCS) Goals : Pedestal/noise, calibration procedures are ready and tested Clustering and hit reconstruction seems to work fine. Alignment and tracks : needs tracks ! → tracking algorithm modified to reconstruct tracks without all the chambers (to be tried on Feb/Mar cosmic data) During (or before) the next run, St have to be included in the readout. As soon as a chamber is validated at the “local commissioning” level, it can be included easily in the global DAQ.

Action to Completion Station 1 : ready for beam (dead channels ? but <<1%, all HV ok ≡ 1650 V ) Station 2 : ready for beam (dead channels ? but <<1%, all HV ok except 1 group/24) Station 3 : finishing the local commissioning ch5 is almost done (readout ok, some very localized pedestal issues) ch6 is installed (open position to finish ch5) ; cabling just started Station 4 : finishing the local commissioning ch7 outside is used to test the noise. Wiener LV PS modified → nice improvements (noise went down between 1.5 and 3.5 ADC ) ch 7 inside has some problems. Needs to be retested ch8 not tested. Readout cabling to be done Station 5 : finishing the local commissioning ch9 readout is ok (a few slats have problems). HV to be tested ch10 cabled, readout tests starting next week. Still a lot of work to do before the next cosmic run. Dimuon tracking meeting tomorrow afternoon to define goals and strategy. 1- St 3,4,5 local commissioning implies no dipole field 2- Probably muon trigger only during next run

Conclusion Very good behavior of St1+St2 was achieved during data taking Readout (CROCUS) is compliant with DATE and Trigger patterns handling is fine (L1/2 reject are implemented and tested in lab) 2 LDCs ok, 3 LDCs (when addinh chamber 5) was straightforward → very confident to include easily remaining chambers software for data taking (DA, ECS scripts, MOOD) are in very good shape AMORE/QA are being developed offline reconstruction has been running fine (2 runs with problems in the data transfer → fixed ) Dimuon « offline shifters » have developed tools and ran the reconstruction → first results with clusters/single muon triggers → working on getting tracks

Muon_trk questions One issue related to the debugging of the DA (and maybe other debugging). The online cluster is completely isolated from the outside word. To be more precise, we need : - A machine where we can play with the data and with the DA program (sources, compiling, debugging) in the same conditions as an LDC. We have some CERN (dimlab04, 05,...) where the code can be installed but we don't have the data (in the DATE format, as we have online). During the last cosmic run we fail to reproduce a segmentation fault observed online in one of our CERN. Since we don't made the test with the same data, how can we compare ?