The time of flight detector for the ALICE experiment

Abstract For the identification of particles in the momentum range 0.5 to 2.5 GeV /c the ALICE experiment uses a time of flight array. The detectors used are Multigap Resistive Plate Chambers (MRPC) with 50 ps time resolution. The whole array covers a ∼150 m 2 area and consists of detector elements in the form of MRPC strips. To cope with the high multiplicity expected for heavy ion collisions, the TOF array is segmented; pickup pads of 2.5×3.5 cm 2 are used. Thus the whole system will have 160 000 read-out channels. Here we present results of the R&D program of the last 3 years, which led to the design of the final TOF system for ALICE