Protecting the world’s largest particle accelerator

When CERN’s Large Hadron Collider is fully operational, it will accelerate countercirculating protons to energies of 7 TeV, the highest particle energy ever achieved by human ingenuity. By macroscopic standards, 7 TeV (10^-6 J) is tiny. But each beam produced at the LHC will ultimately include some 3 × 10¹⁴ protons; should it go awry, it could seriously damage the LHC and the delicate particle detectors that the accelerator hosts. For that reason, as described in a new paper by Robert Appleby and colleagues at CERN, the LHC includes an elaborate safety system that regulates the beams, monitors them, and dumps them out of harm’s way if they go off course. To give an idea of the system’s complexity, the authors note that 17 distinct subsystems must continually give a virtual OK to a central processer, or else the beam will be dumped. In addition to describing the...