Indian contribution at CERN

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Indian contribution at CERN
Photon Multiplicity Detector
For ALICE Experiment, CERN
Indian Collaborators

• Institute Of Physics, Bhubaneswar
• Indian Institute of Technology, Bombay
• Jammu University, Jammu
• Punjab University, Chandigarh
• Rajasthan University, Jaipur
• Variable Energy Cyclotron Centre, Kolkata

21st June 2007
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What is PMD

• Basic Physics goal is to understand the
  ultra-relativistic heavy ion collisions and
• get signature of Quark Gluon Plasma (QGP)

• Photon Multiplicity Detector (PMD) allows
  event-by-event measurement
• of photon multiplicity and the spatial
  distribution of photons in the preshower
• mode along with charge particle veto.

To achieve above goal

• H.R.
• 30 scientists
• 10 students

Installation of detector system and services at
point 2 (ALICE site)

• Physics simulation
• Detector simulation
• Electronics simulation

Computation and software facility for data
analysis, interpretation of data for achieving
physics goals

• Detector hardware
• design and fabrication
• Control and monitoring
• instrumentation

• Prototype testing with test beam
• SPS and PS beam at CERN
• Offline sub system testing _at_CERN
• High voltage testing of modules
• Readout electronics testing
• Readout module testing

• Readout Electronics design
• and fabrication
• Data Acquisition and trigger
• Software development to handle
• data processing

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Photon Multiplicity Detector(PMD) in ALICE
173.35cm
361.5 cm from IP inside mini frame.
A Large Ion Collider Experiment
150.28cm

• PMD is a pre-shower detector with three radiation
  length of photon converter (lead) and honeycomb
  type cellular gas proportional chamber (active
  element).

21.7cm
PMD module
49.05cm
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Principle of PMD

• Some of the features of PMD
• Total no. of cells in PMD 221184
• in VETO and PRESHOWER plane
• Sensitive medium Gas ( Ar CO2
• in the ratio 7030)
• Z-distance 361.5cm from IP
• ?-coverage 2.3 to 3.5
• F-coverage 0 to 2p
• Cathode Copper plate
• Anode Gold plated tungsten wire
• Operating voltage -1350V to -1400V

• Cell thickness 5.0mm
• Cell diameter 5.0mm
• Cell wall thickness 0.2mm
• No. of cells in one module 4608
• No of modules 48

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Different stages in PMD module fabrication
Top PCB
20.9cm
Honey comb
Bottom PCB
48.2cm
Single cell/honeycomb
Edge frame
Single strip
Honey comb array
Stainless steel frame with base plate
PMD module
Storing modules
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FEE BOARD
Readout Electronics
FEE Board
1) Reads 64 analog signals (honeycomb cells) from
the detector. 2) Converts Analog to digital by
serial 12 bit , ADCS (AD7476). 3) The 4 MANAS
Chips and 2 ADCS are controlled by MARC (MUON
ARM READOUT CHIP). 4) MANAS is 16 channels
Multiplexed AN alog And Signal Processor. 5)
Communicates with DSP (CROCUS -DAQ) through LINK
PORT BUS (4 bit) 6) 16 MHZ crystal ( not shown
here) for MARC .
All the FEE board assembly are arriving from
India in batches
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PMD DATA Readout Architecture
Total no of cells 221184 Total no of Modules
48 1 module 4608 cells.
1 CROCUS - 50 Patch Buses 6 CROCUS 300 Patch
Buses
Patch Bus
2 32 cells
CHAIN
Translator
DDL
LDC
CROCUS
40 meters LVDS LINKPORTS TRIGGER BUSY, and L0
LTU
CTP
GDC
TRIGGER
L0
BUSY
VME TRIGGER DISPATCHING
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Testing ALICE PMD Module _at_ CERNduring Test Beam
using electron and pion beams
For detector Calibration, performance and
understanding problems.
Test set up at CERN
TRIGGER SCINTILLATORS
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Offline Preparation for PMD installation
Electronics readout system testing just initiated
HV testing of 48 PMD modules
Data Acquisition sytem
Some FEE board mounted on PMD module