At CERN, an option of installing Hollow Electron Lenses for HL-LHC is being studied. Full details in Accelerating News | Issue #28.
Electron Lens Test Stand at CERN
Electron Lens Test Stand at CERN
Hollow Electron Beam around the circulated beam (left hand side) and schematics of the Collimation Scheme for HL-LHC (right hand side). (Courtesy of Stefano Redaelli, CERN)