CERN UPDATE | CRYSTALS CHANNEL HIGH-ENERGY BEAMS IN THE LHC
“Bent crystals can be used to deflect particle beams, as suggested by E. Tsyganov in 1976. Experimental demonstrations have been carried out for four decades in various laboratories worldwide. In recent tests, a bent crystal inserted into the LHC beam halo successfully channelled and deflected 6.5 TeV protons into an absorber, with reduced secondary irradiation.
Bent crystal technology was introduced at CERN and further developed for the LHC by the UA9 Collaboration. For about ten years, experts from CERN, INFN (Italy), Imperial College (UK), LAL (France), and PNPI, IHEP and JINR (Russia) have been investigating the advantages of using bent crystals in the collimation systems of high-energy hadron colliders. A bent crystal replacing the primary collimator can deflect the incoming halo deeply inside the secondary collimators, improving their absorption efficiency. “The bent crystals we have just tested at the world-record energy in the LHC were built in Russia and Italy and then meticulously optimised in the H8 line at the SPS North Area,” explains Walter Scandale, head of the UA9 collaboration. “The successful results were made possible by the strong support we received from the Accelerator Sector Management and the EN-STI group in close collaboration with the LHC collimation team.”