PHOTON MULTIPLICITY DETECTOR 

(PMD)

 Multiplicity and spatial distribution of photons on an event-by-event basis in high energy heavy ion experiments searching for signals of Quark-Gluon Plasma (QGP).

We study:

• Deconfinement transition:    Fluctuations of global observables
• Chiral symmetry restoration:    Disoriented Chiral Condensates (DCC)
• Matter under extreme conditions:    Equation of State - Event shape and flow

We are involved in the following experiments:

• WA93 at CERN-SPS completed data taking in 1991
• WA98 at CERN-SPS completed data taking in 1996
• STAR at BNL-RHIC:  PMD to be installed in 2002
• ALICE at CERN-LHC:  PMD to be installed in 2005

PMD collaboration consists of:

• IOP, Bhubaneswar
• VECC, Calcutta
• Panjab University, Chandigarh
• Jammu University, Jammu
• Rajasthan University, Jaipur
• IIT, Mumbai

Photograph of a PMD prototype tested at CERN in May 2001:

The photograph shows a 96 cell prototype of the honecomb proportional counter of the Photon Multiplicity Detector (PMD) to be installed in the STAR experient at BNL-RHIC and the ALICE experiment at CERN-LHC. The PMD has a honeycomb geometry, the cells of which are 8 mm deep with a surface of about 1cm2. Copper walls separate the cells in order to prevent signals from blowing up by confining low-energy electrons to a single cell. The honeycomb array, PCBS and the
GASSIPLEX board are cleary visible in the picture. In the assembled version, the PCBs form part of a gas-tight chamber having a high voltage connection and inlet/outlet for the gas. Only the gas inlet is visible in the picture. This prototype has been successfully tested at CERN. 

For more information click on the left buttons or

contact:  pmd@veccal.ernet.in