ALICE detector upgrade assembly at CERN. ALICE (A Large Ion Collider Experiment) is a detector built around the Large Hadron Collider (LHC) at CERN (the European particle physics laboratory) near Geneva, Switzerland. The LHC, the world's largest and most powerful particle collider, began operating in 2008. For ALICE, beams of ions are accelerated to collide head-on. The LHC energies have allowed study of exotic material like quark-gluon plasma, a form of quark matter. Here, an upgrade known as the Time Projection Chamber (TPC) Gas Electron Multiplier (GEM) is being assembled in a clean room. Photographed on 11 January 2019.