Prototype tests of the Alice Photon Multiplicity Detector

by Anand Kumar Dubey (Institute of Physics, Bhubaneswar, India)

Friday 22 Jun 2001, 11:00 → 12:00 Europe/Zurich

13/2-005 (CERN)

The Alice Photon Multiplicity Detector (PMD) is a preshower detector to be used to measure the photon multiplicity and give estimates of the transverse electromagnetic energy. The PMD consists of a regular array of about 200,000 hexagonal cells, each having an area of cm² and a depth of 8 mm. The cells act like a proportional counters with the cell wall as cathode and a wire passing through the axis as anode. Field simulations were done to optimise the cell design. A prototype detector with 96 cells has been fabricated and tested at the CERN PS and SPS. The detector was subjected to pion and electron beams of varying energies in order to study the single cell and preshower characteristics. Under optimised operating conditions, the charged particle detection efficiency was found to be about 97%. The charged particle signal is confined to almost one cell as required by the design. The transverse spread of the preshower in data is found to be close to that given by GEANT 3. The energy response was found to be linear.

Organiser(s): Ariella Cattai / EP Division