11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions

The addition of a Forward Calorimeter (FoCal) to the ALICE experiment is proposed for LHC Run 4 to provide unique constraints on the low-x gluon structure of protons and nuclei via forward measurements of direct photons. A new high-resolution electromagnetic Si-W calorimeter using both Si-pad and Si-pixel layers is being developed to discriminate single photons from pairs of photons originating from ${\pi }^0$ decays. A conventional sampling hadron calorimeter is foreseen for jet measurements and the isolation of direct photons. In this presentation, we will report on results from recent test beam campaigns at CERN with Si-pad and pixel modules, a first prototype for the hadronic calorimeter, as well as the physics prospects.