MODEL RELEASED. CDF particle detector at the Fermi National Accelerator Laboratory (Fermilab) near Chicago, USA. The CDF (Collider Detector Facility) records subatomic particles created in high-energy proton-antiproton collisions in the Tevatron coll- ider. It co-discovered the top quark in 1994. Here the detector is partly disassembled between operation runs. The black segments (left) are part of the outer muon chambers. The red areas are part of the magnet which bends charged particles travelling out from the collision point. The blue segments (right) are part of the hadron calorimeter. When in use these parts are closed tightly together. Photographed in 1998. The physicist is ROB ROSER.