Michele Bianco
Physics Dept. University of Lecce – INFN Lecce
10th ATLAS MUON WEEK CETRARO-ITALY July 10-16 2005
The ATLAS RPC
Cosmic Ray TestStand in Lecce:
Setup and Status
Outline:
• The ATLAS Muon Spectrometer
• Cosmic Ray Test Stand in Lecce
• The Automatic Test Procedure
• Examples of Test Results
• Database of Lecce Test Stand
• General Results and Statistical Distributions
The ATLAS Experiment and the Muon Spectrometer
Resistive Plate Chambers (RPC) will be used as Muon Trigger Detector in the barrel region (-1 < < 1)
More of 1100 RPC units
26 different chambers type
Total surface ~ 4000 m
2The Lecce Cosmic Ray Test Stand
A cosmic ray stand was designed and built in the Lecce laboratory in order to test the ATLAS RPCs
The stand is built with 4 RPC units for triggering and
tracking cosmic rays
It can host up to 8 standard units to test simultaneusly for a total of 4736
read-out channels
The Lecce Test Stand The hardware set up
Slow Control PC
Latch and Receiver modules
Low voltage distribution panels
Gas system control PC
Gas system
HV Power supply
Pulse
generator
The Lecce Test Stand The hardware set up
High flexibility
With the our setup we can test 23 out of 26 different types of RPC constructed for the ATLAS Spectrometer .
8 Standard modules under test
16 S2 special modules under test
Simultaneus test
of standard and
special modules
under test
The Lecce Test Stand
The software tools
Detector Control Sistem (DCS)
Data Acquisition Sistem (DAQ)
Event Display (On Line)
Data analysis C++
MALICE (Muon Analysis of Lecce Instrumentation for Cosmic Events)
Data Storage ( MySQL Database)
Results Presentation ( Dinamic Web Page PHP language)
LABView
The Test Sequence
•Preliminary Operations (cabling and gas flushing)
•Pulser Test (to debug front-end read-out connection)
•HV Scan for I-V Curve
•Efficiency Plateau at five different thresholds
•Random Trigger for noise measurement
•Gas Volume Tomography to exclude local inefficiency
•Gas Leak Test
•During the test the working and environmental parameters (HV, gap and Power Supply currents, gas flow, temperature, humidity, atmospheric pressure etc.) are continuously monitored and stored.
All operation need only 72 hours !!!!!
Many thanks to Naples Group for the
two custom made 128-channel pulser
Quick Test: Certificated chambers
which undergoes substitution of panel N°1 has been re-tested by a “Quick test”.
•Preliminary Operations (full cabling)
•Pulser Test (to debug front-end read-out connection)
•HV Scan (from 0 Volt to 3000 Volt) in order to verify ohmic contribution at the gap current.
•Gas Leak Test
• During the test the working and environmental parameters (HV, gap and Power Supply currents, gas flow, temperature, humidity, atmospheric
pressure etc.) are continuously monitored and stored
All operations need only 8 hours !!!!!
50 BOSB quick tested: 48 accepted + 2 rejected
4 BOSC quick tested: 4 accepted
Data storage and Presentation
All Results for each Chambers Tested are
available on web with php page
Tracking Resolution and Tomography
Gaps with cut-out
Preliminary Results for Chamber delivered to CERN
HV=10.2kV HV=10.1kV HV=10.0kV
Penv=1013mb Tenv=200C
HV=10.2kV HV=10.1kV HV=10.0kV
Penv=1013mb Tenv=200C
HV=10.2kV HV=10.1kV HV=10.0kV
Penv=1013mb Tenv=200C
T
env=20
0C
Dead channels included
Dark current distribution of BOS gas volumes
Dark current distribution of BMS gas volumes
Units BMS2
Conclusions
Lecce Cosmic Ray Teststand is able to test 16 RPC/week and it is routinely certifying and delivering high quality RPC units to build the ATLAS spectrometer in time.
We aspect to finish in October
The ATLAS RPC single component failure rate is relatively small.
ATLAS RPC with cut-out gas volumes have been successfully built and tested.
We have tested 250 Chambers:
125 Chambers at Cern
42 BOS Chambers and 40 S2 Chambers ready to be sent
We have to test others 90 BOS Chambers and 50 S2-S3 Chambers
Future Plans
