Analysis Drift velocity of the SDD Detector Martin A. Subieta INFN Torino Introduction SDD detector Drift velocity Description of ITS Layer 3 & Layer 4 Status of the anodes for all modules Analysis Mean Drift velocity and Time bin for all Modules Mean Drift velocity on the Ladders Mean Drift velocity and Time bin in function of the runs (fluctuations in the time = 1 minute of data analyzed per run) Conclusions Palau, Sardegna September 30th

SDD Detector Analysis Drift Velocity of the SDD Detector Side 0

Drift Velocity The particle cross the detector and produces the electron’s cloud Electron’s cloud goes until the anodes The drift velocity is the mean velocity of the electrons Z X Analysis Drift Velocity of the SDD Detector

ITS Layer 3 & Layer 4 Total Modules 260 Layer 3 Layer 4 N° of Ladders 14 22 N° SDDs per Ladder 6 8 Total Modules 260 Analysis Drift Velocity of the SDD Detector

Injectors Lines 2 1 3 Status pad injector 5 6 7 Pad 1 & 3 Pad 2 & 3 Analysis Drift Velocity of the SDD Detector

Status Injector Pad Statistics Total number of pads are 17160 45 % of the pads have status 7 18 % have status 6 1.2 % have status 5 16.8 % have status 1-4 19 % have status 0 Pads 1 & 33 not working for almost all modules Analysis Drift Velocity of the SDD Detector

Statistics of Modules Status 7 Side 1 pad 7 have more modules with status 7 Side 0 pad 27 have more modules with status 7 For both sides we have more of the 50% of the total number of modules with status 7 Analysis Drift Velocity of the SDD Detector

Analysis Mean Drift Velocity (Vdrift) Analysis of the Vdrift of the pad 7 for one side for the run 51971 (one minute data taking analyzed) Vdrift distribution for all modules Time bin (Time bin centroid for the 2nd line injector) distribution for all modules Vdrift distribution on the ladders Analysis of the Vdrift for the modules 302 and 372 for 7 runs ( 1 every hour ) Vdrift in function for the runs of August 14th taken each hour Time bin of the pad 7 in function of the same runs Runs Data 14/08/2008 51954 51959 51971 51981 51986 51999 52005 Analysis Drift Velocity of the SDD Detector

Mean drift velocity for all modules Most modules have Close to 0,08% of error, except for two. the minimum mean velocity is close to 6.3 (μm/ns) and the maximum close to 6.8 (μm/ns) Layer 3 Layer 4 Module 273 Module 483 Analysis Drift Velocity of the SDD Detector

Time bin centroid for all modules We take the central injector line for the analysis Only modules with anodes with status 7 are plotted Layer 3 Layer 4 Analysis Drift Velocity of the SDD Detector

Mean drift velocity for all modules The picture shows the fluctuations in the modules with status 5,6,7 Most modules have less than 1 per thousand of error Layer 3 Layer 4 Analysis Drift Velocity of the SDD Detector

Time bin centroid for all modules We take the central injector line for the analysis Only modules with anodes 5,6,7 are plotted Layer 3 Layer 4 Analysis Drift Velocity of the SDD Detector

Mean drift velocity on the ladders Drift velocity depends on temperature Top layer 3 ≈ 25 °C Bottom layer 3 ≈ 23 °C Top layer 4 ≈ 22 °C Bottom layer 4 ≈ 20 °C Analysis Drift Velocity of the SDD Detector

Mean drift velocity vs runs Stability of the Vdrift on the time =1 min of data analyzed fluctuations of the Vdrift around of the mean on the all runs We have a stability close to 1 per thousand for each run, which remains for 7 runs analyzed Analysis Drift Velocity of the SDD Detector

Time bin in function of the runs Stability of the Time bin on the time is less than 1 per thousand This stability remains for all runs analyzed Analysis Drift Velocity of the SDD Detector

Conclusions The 63% of the pads for all 520 semi-modules have status 6,7. For the modules with anodes that have status 7 the fluctuations of the drift velocity in 60 events collected in 1 minute , have less than 1 per thousand of error. Drift velocity observed on the ladders indicate a higher temperature on layer 3 than on layer 4. And a higher temperature on the top ladders than on the bottom ones 4. We have a difference close to 5 °C between layer 3 and layer 4 5. Analysis on Vdrift and the Time bin for six hours (every hour with 1 minute of data analyzed ), shows a stability of the order of 1 per thousand Analysis Drift Velocity of the SDD Detector