ssd status
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SSD STATUS
Enrico Fragiacomo – INFN Trieste
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Outlook
MC-data comparison Cluster finder dE/dx Material budget in geometry
ITS alignment&offline - CERN 4/29/2010
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MC-data #recpoints ratio mod-by-mod
900 GeV sim pp and real data from run 104799
p0: 1.02244 +/- 0.0119124 p0: 1.01755 +/- 0.0109631
Strongly depends on sim production and run dates! See later…
Ramona L.
ITS alignment&offline - CERN 4/29/2010
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MC-data recpoints ratio lad-by-lad
Selected modules from previous slide removed!
ITS alignment&offline - CERN 4/29/2010
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MC-data bad channels ratioV2 map in OCDB before March, 31th
V3 map in OCDB after March, 31th
Run 1
14786 f
rom
Marc
h,
30th
ITS alignment&offline - CERN 4/29/2010
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MC objects: BadChannelsSSD & NoiseSSD updated on March 31st
Used from LHC10b1 (run 114786) GainSSD updated on February 22th
Globally (fixed map): BadChannels on Pside: 10.81% BadChannels on Nside: 8.92%
DATA objects: BadChannelsSSD & NoiseSSD updated at each Physics fill (~daily) GainSSD updated on February 22th
Possible relevant run-by-run fluctuations in DATA of the BadChannels number : module #1548 – P side: completely off in some runs fluctuation in ~30 module-Psides on Layer6 (sensitive to humidity):
hundreds of channels can be off in some runs (128ch =1/6 module-side) statistical fluctuation (3σ-noise cut for BadChannels)
Globally (April2010 distribution): BadChannels on Pside: 10.92% - RMS = 0.07% BadChannels on Nside: 8.94% - RMS = 0.01%
Data-MC consistency in Calibration Objects
Mino C.
ITS alignment&offline - CERN 4/29/2010
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DIFFENCE BETWEEN BAD CHANNELS (Simulation-Data)
MOD 1010: p-side sintef noise -> not insulated
MOD 1608: p-side sintef noise -> not insulated
MOD 1618: p-side sintef noise -> not insulated
101016081618
1548
MOD 1548: P-side off in some runsSSD Numeration (0 -
1698)
V3 sim and data from run 114918
ITS alignment&offline - CERN 4/29/2010
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DIFFENCE BETWEEN BAD CHANNELS (Simulation-Data)
SSD Numeration (0 - 1698)
635
MOD 635: n-side very low noise -> tagged as 'dead' in the calibration run used for the simulation but alive during the data taking!
V3 sim and data from run 114918
ITS alignment&offline - CERN 4/29/2010
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Summary (1/2)
All modules with ratio <0.8 and >1.2 have been checked
Almost all of them reflect a different condition in the DATA-MC OCDBs.
For the other smaller discrepancies: the spikes
above 1 correspond in most of the cases to the last module in a ladder (position 22).
Structures on the half-ladder basis: in many cases the A-side half-ladder has a lower ratio with respect to the corresponding C-side half-ladder.
Mino C.
ITS alignment&offline - CERN 4/29/2010
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Summary (2/2)
9 modules with ratio < 0.8: 1 P-side off in some runs (2048) 6 P-side noisy (strips not insulated)
(2108,2118,1510,1506,1629,1860) 2 modules with very low noise on one side--> tagged as bad
(525, 1135)-->probably to include back!
1 module with ratio > 1.2
always good about noise, many channels masked because of old defects, now recovered (1154) --> to include back!
general: module in position 22 always higher ratio (~1.1) module in position 1 often lower ratio A-side lower ratio wrt C-side ITS alignment&offline -
CERN 4/29/2010
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Cluster finder
Activity ongoing on the cluster finder optimization (Sasha B.+EF): 1. some small fixes in the clusterization 2. tricks to speed it up (as suggested by the
HLT), 3. eta distribution
ITS alignment&offline - CERN 4/29/2010
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dEdx
MPV as function of module number for different 7TeV runs and pass6 of 900 GeV.
Main conclusion: The gain looks to be stable in time but there are few bad modules which have huge fluctuation on gain. They are under investigation
Marek C.
ITS alignment&offline - CERN 4/29/2010
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Material distribution from conversions
Savannah 63965 F. Bock
SDD, SSD show 10-20% more conversions than expectedSPD situation unclear; depends on V0 finder?
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Labeling conversions in MCAdded code in AliITSv11Hybrid::StepManager
to histogram conversions
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Material SSD
Main contributions:Sensor (42%), ladder cables (18%), spaceframe (8.5%), cooling tubes+water (7.8%)
Table from design:
ITS alignment&offline - CERN 4/29/2010
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Main missing components
Cross-checked contributions in MC with table, good agreement foundAll large contributions accounted for
Few small parts missing: metal caps on capacitors + solder, approx. 0.18 g per module (out of 2.66 g per module, 6.371 g ladder segment)
0.05 % X/X0 out of 0.876 % total
Added to MC, not committed yet. Will reduce discrepancy
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Latest news
The main update is that everything has now been committed to AliRoot trunk. The changes are:1. inclusion of metal endcap of
capacitors+solder2. change of density carbon-fiber 1.6 -> 1.8,
also for support cone.3. some small changes to ladder cables:
increase in kapton, decrease Al, accroding to measurements Ton; net effect of this is probably negligible.
ITS alignment&offline - CERN 4/29/2010
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