ALICE Zero Degree Calorimeter (ZDC), General Pictures.

The ZDC Calorimeter for spectator neutrons is made by 44 slabs of W-alloy; each slab has 44 grooves where quartz fibres are placed. The charged particles of the hadronic shower generated by the neutrons make Cerenkov light in the fibres and the light is collected by photomultipliers. Photos from 1 to 9 show the front-face of the calorimeter. Photo n. 10 shows the rear of the calorimeter where the fibres are divided in several groups to go to the different PMs.