ATLAS detector. Engineer standing on a platform in front of the ATLAS (a torodial LHC apparatus) detector (circular) at CERN (the European particle physics laboratory) near Geneva, Switzerland. The detector will be placed around the large hadron collider (LHC), CERN's highest energy particle accelerator. ATLAS is a general-purpose detector designed to measure the broadest possible range of particles and physical processes that could result from the collision of the proton beams within the LHC. A pilot run of the LHC is scheduled for summer 2007.