SDD in February ‘08 cosmic run Davide Falchieri Universita’ e INFN, Bologna Francesco Prino INFN Sezione di Torino Commissioning workshop – April 1st 2008

Summary SDD running conditions in Feb08 cosmic run Calibration runs and data in OCDB PEDESTAL and PULSER Baselines, Noise, Gain INJECTOR Drift speed Cosmic hits on SDD Outlook

SDD running conditions

ECS/DCS/HLT DCS ECS HLT Operated and controlled via PVSS SW Experienced quite frequent blockings of the user interface DCS Finite State Machine integrated in the ECS ECS Operation sequence: DAQ initialization (reset RORC, DIU, SIU) – Send JTAG commands Initializes TTC (resetting TTCrx  requires extra initialization procedures done by the CARLOSrx acquisition cards) PULSER and INJECTOR runs types (used for SDD calibration, see next slide) correctly implemented (i.e. with proper DA launched at EOR and limitation on number of events) starting from March 5th HLT Not used

ECS run types and SDD config STANDALONE No DA launched at the end of run PEDESTAL To measure baselines and noise (using ITSSDDBASda) No zero-suppression and no baseline equalization PULSER To measure gain from test pulse (using ITSSDDGAINda) Turn on PASCAL test pulse INJECTOR To measure drift speed from injectors With baseline equalized and zero-suppression active Switch on pre-pulse trigger PHYSICS Baseline equalized and zero-suppression active Masking of noisy anodes not activated Output written in OCDB in directory CalibSDD Output written in OCDB in directory DriftSpeedSDD

Ladders used Cooling available only on the top half of the SDD layers # of modules: 36  coverage: 0-155˚ Layer 4 Ladder used: 1-12 # of modules: 96  coverage: 0-196˚

DDLs used

Excluded modules Some modules gave problems when running at high trigger rate (> 500 Hz) Data synchronization is lost after short time Acquisition is blocked Problem affecting 37 modules, presently under investigation These 37 modules have been removed from the configuration used in February run Other 3 modules of ladder 4 of layer 3 are dead Resulting module statistics: Total number of modules with cooling 132 Modules excluded for various problems 40 Total number of modules in DAQ 92 88 of them supplied at the nominal HV of 1800 V

SDD geometrical coverage

Problems with BUSY Starting from Feb 27th we observed the SDD go in busy and block the acquisition after few minutes with the ACORDE trigger (95 Hz) in the global partition Problem appears only when SDD are slowest detector in the global partition No problem when running with in the global partition with TOF trigger (rate 1 Hz) Everything OK in standalone mode In order to be able to take data in the global run on March 5th we increased the busy time from 407 ms to 2025 ms, to be sure that AMBRA chips work in single buffer mode In this configuration data taking was stable for the following days also as slowest detector in the partition Under investigation (together with synchronization problems)

Calibration Runs and data in the OCDB

CalibSDD objects in OCDB Baselines, noise and gain for each anode extracted by DAs from PEDESTAL and PULSER runs PULSER runs (with DA automatically starting at EOR) implemented and correctly working starting from March 5th Previous calibration runs were taken as standalone (no DA) Should be analyzed offline DA+preprocessor for baselines noise and gain properly working starting from run 25410 Results checked offline for few runs and are ok Conclusion: OCDB/ITS/Calib/CalibSDD files are ok for first reconstruction pass for runs > 25410 To-do: Offline analysis of calibration runs < 25410 Complete validation of DA output

Example plots: PEDESTAL run 23665 Noise distribution for good anodes Baseline distribution for good anodes

Example plots: PULSER run 23668 Gain from test pulse signal to pre-amplifier input Anode statistics: Total number of anodes in DAQ 47872 Number of noisy and bad anodes (from PEDESTAL) 337 (0.7 %) Number of dead anodes (from PULSER) 110 (0.2 %)

Zero suppression thresholds Thresholds for zero suppression kept low in the first part of the run (i.e. before March 4th) For few anodes with larger noise, all time bins pass the thresholds and are recorded Typically occurring on anodes 0 – 64 – 128 – 192 which stay on chip edges and are more affected by common mode noise

DriftSpeedSDD objects in OCDB Drift speed for each module extracted by DAs from INJECTOR runs INJECTOR runs (with DA automatically starting at EOR) implemented and working starting from March 5th BUT problems with: Modules with injectors not working Threshold for injector cluster finding (optimized for non zero suppressed data) Solution (OK for first reco pass): Calibration object produced offline by analyzing run 25411 and put in the OCDB with validity from run 25000 to run 999999 Drift speed for modules with bad injectors set to the average value To-do: Offline analysis of all injector runs Extrapolate drift speed for modules with bad injectors according to the observed ladder dependence

Drift speed from injectors 33 (1 each 8 anodes) x 3 injectors on each half module Drift speed depends on anode number Drift speed depends on temperature vdrift = meE with meT-2.4 Heat sources on detector edges Fit with 3rd order polynomial Fit parameters stored in OCDB

Drift speed vs. ladder position Drift speed depends on temperature vdrift = meE with meT-2.4 Heat goes up Top ladders: higher T, lower drift speed temperature Drift Speed (mm/ns) Module number LAYER 3 LAYER 4

Drift speed stability From run 24906 collected with muon trigger about 5 triggers/minute, 200 analyzed events from 1 raw data file Drift speed constant on a time scale of 1 hour of data taking Timestamp=1204588292 Mon, 03 Mar 2008 23:51:32 GMT Timestamp=1204592726 Tue, 04 Mar 2008 01:05:26 GMT

Cosmic hits on SDD

Strategy Start from SPD points (global coord. provided by Henrik) Perform a simple tracking (linear fit) and calculate (with simplified geometry) which modules are hit on SDD layers Run22252 012.2990 ev 31 (32 online)

SDD raw data (I) Look at SDD data on the modules pointed by SPD track Run22252 012.2990 ev 31 (32 online) Layer 4 – Ladder 9 – Det 4 Low momentum particle (≈3 MIP) Cosmic Hit

Reconstructed cluster (I) Calculate cluster coordinates using an average value of drift speed and no correction for time offset Plot with EVE

Reconstructed cluster (II) Other 2 golden events from run 22252 Run22252 019.420 ev 84 (85 online) Run22252 001.3630 ev 100 (101 online)

Outlook

Cooling development (F. Tosello) 78 pressure sensors (mounted as near as possible to the detector) calibrated and installed but not yet electrically connected (new PLC not yet available) 52 flow meters All calibrated 34 out of the 52 : calibrated and mounted, the remaining ones will be delivered this week. Planning proposed by A.Tauro wk 15 (or 16): Plant in stop mode; cutting of SSD(16) & SDD(5) lines in C-side and connection to the new tubes (18mm return lines) wk 16 (April 14): the 'detector' PLC installation in the pit wk 17 (April 21): cabling of the 'detector' PLCs; cabling of the HW interlocks wk 18 (April 28): plant in RUN mode, debugging. wk 19 (May 5) : plant (hopefully) available

DCS development (J. Kral) J.Kral tried to install the new ISEG OPC server (HV). It has more stability problems than the old one. J.Kral is in contact with Lionell Wallet (CERN) to understand were the problem can be. The old OPC server has still to be used for the next weeks.

Data Analysis Implement a method for noise suppression in the cluster finder to reduce the number of noise clusters due to the use of low zero-suppression thresholds Include SDD points in the ITS tracking Tune time offset Parameter to be used to convert from measured drift time to drift coordinate (accounts for trigger and electronics delays) To be tuned from the residual between track reconstructed from SPD (and SSD) and cluster position Extract (if possible) some info about alignment (at least for the z coordinate measured by anodes) Tune ADC to keV charge conversion constant To be tuned from the charge deposit by a cosmic muon (MIP)

Backup

Injector status