High-energy high-luminosity e+e− collider using energy-recovery linacs

In this letter we present a novel approach for a high-energy high-luminosity electron-positron collider. Present designs for high-energy electron-positron colliders are either based on two storage rings with 100 km circumference with a maximum CM energy of 365 GeV or two large linear accelerators with a high energy reach but lower luminosity, especially at the lower initial CM energies. A shortcoming of the collider based on storage rings is the high electric power consumption required to compensate for the beam energy losses from the 100 MW of synchrotron radiation power [1]. We propose to use an Energy Recovery Linac (ERL) located in the same-size 100 km tunnel to mitigate this drawback. We show in this letter that using an ERL would allow large reduction of the beam energy losses while providing higher luminosity in this high-energy collider operating at or above 140 GeV center-of-mass energy. Furthermore, our approach allows for extending the CM energy to 500 GeV, which would enable double-Higgs production, and even to 600 GeV for tt‾H production.