atlas semiconductor tracker
DESCRIPTION
Atlas SemiConductor Tracker. Andrée Robichaud-Véronneau. A Toroidal Lhc ApparatuS. The Atlas Detector is divided into several subdetectors Out of them, 2 systems are using silicon sensors technologies: SCT Pixels. - PowerPoint PPT PresentationTRANSCRIPT
Atlas SemiConductor Tracker
Andrée Robichaud-Véronneau
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny 2
A Toroidal Lhc ApparatuS
The Atlas
Detector is
divided into
several
subdetectors
Out of them, 2 systems are using silicon sensors technologies:
SCT Pixels
One central barrel with 4 layers of rectangular modules
2 end-caps containing 9 disks
Each disk assembled with max. 3 concentric rows of wedge-shaped modules (Made in Geneva)
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny 3
The SemiConductor
Tracker
61 m2 of Si resulting in 6.2 million readout channels 4088 double-sided modules, coverage 2.5 Modules using optical communication (CLK/COM) Operation temperature : -7 oC (on the Si sensor) using C3F8 Radiation hardness : 2x1014 1-MeV neutron equivalent ·cm-2 (10 years LHC)
Journée de réflexion DPNC - Cartigny 4
From SCT to ID
Different assembly phases for the SCT
2004-2005 Assembly of individual barrels in Oxford Reception testing of the barrels at CERN 4-barrel assembly EC assembly in NIKHEF and Liverpool
2006-2007 ID Barrel integration (SCT->TRT) EC reception at CERN ID Barrel Combined Testing (Cosmics) ID Barrel Integration in ATLAS ID EC integration (A and C) ID EC C Combined Testing (Cosmics) ID EC integration in ATLAS
Andrée Robichaud-Véronneau
5
Reception testing
Single barrel tests after reception at CERNDec 2004-July 2005
Were tested: Cooling uniformity +stability DAQ & DCS operations Noise performance Signal response
Results:Module condition unchanged compared to module production
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
6
Barrel Cosmics
450 k events taken from March to June 2006
~70 % good tracks
Run at nominal threshold (1 fC)
Allowed for testing of: Online monitoring Event Display Offline
reconstruction Alignment
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
7
In parallel to the detector assembly, the DCS was developed to provide safe operation of the SCT.
It includes the control and monitoring of: Power supplies Environmental conditions (Temp, Humi) Cooling
A hardware interlock on cooling temperature adds an extra protection to the software controls.
The ID combined test were a good opportunity to test these systems and get experience for the final installation.
Detector Control System
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
8
EC C Cosmics
~167 k events taken in December 2006
Scintillators placed to catch horizontal tracks
No dependence on trigger rate in physics mode detected
No influence from TRT activities
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
9
ID integration in ATLAS
ID Barrel lowered in the Atlas pit in Aug. '06 Cabling and testing was completed Feb. '07 EC A was lowered May 25th
EC C was lowered June 18th
The SCT Barrel is now integrated with Atlas central DAQ & DCS
SCT ECs are currently being cabled and currently being tested to participate in Atlas commissioning this fall
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
10
Challenges ahead
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
Evaporative cooling heaters Used to boil off remaining liquid in coolant between detector and cooling plant Main source of unreliability of the cooling system Repositioned outside cryostat Currently being reworked Will be re-installed temporarily for cosmics running
Module resistance Some modules show a high backplane resistance First on EC C, but also on EC A and Barrel (worst) Might be linked with presence of humidity (DCS) Still under investigation (forward biasing solution)
11
Next steps
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny
What will keep us busy for the coming months:
Cabling and testing the SCT ECs
Resolving the heaters issue
Run the detector with cooling inside Atlas (M5 in Oct-Nov 07)
Analyse the first SCT data (alignment, performance)
Manpower is needed for these important steps!
12
Conclusion and Outlook
The SCT is integrated in Atlas Barrel has already been tested for noise occupancy Full scale commissioning in 3-4 months
The integration tests were a great success in many aspects
~99.7 % of barrel channels functional (1 module lost - HV)
Cosmics data taken on surface Still a lot of work to be done!
Continue development of Barrel DAQ & DCS for the fall Connect and Test both End-Caps Integrate the End-Caps with Central Atlas Work ongoing on the evaporative cooling heaters Look into the first data to understand e/ performance
=> Looking forward for the first LHC data!
Andrée Robichaud-Véronneau Journée de réflexion DPNC - Cartigny