Very large lepton collider in the Very Large Hadron Collider tunnel

The Very Large Hadron Collider design is converging on a program where a 233 km circumference tunnel would first be occupied by a low field dipole system producing 40 TeV in the center of mass, followed by a higher field magnet system producing nearly 200 TeV in the center of mass. We consider the possibility of first using the tunnel for a large e⁺e^- collider. We assume that the total radiated synchrotron power will be limited to 100 MW. We describe the design strategy, the luminosity and energy reach, the factors that limit the machine performance, the scaling laws that apply to its design, and the technology that would be required for its implementation.