First experimental evidence of a beam-beam long-range compensation using wires in the Large Hadron Collider

Abstract

In high intensity and high energy colliders, such as the CERN Large Hadron Collider (LHC) and its future high-luminosity upgrade, interactions between the two beams around the different interaction points impose machine performance limitations. In fact, their effect reduces the beam lifetime, and therefore, the collider’s luminosity reach. Those interactions are called beam-beam long-range (BBLR) interactions, and a possible mitigation of their effect using dc wires was proposed for the first time in the early 2000’s. This solution is currently being studied as an option for enhancing the HL-LHC performance. In 2017 and 2018, four demonstrators of wire compensators have been installed in the LHC. A 2-yearlong experimental campaign followed in order to validate the possibility to mitigate the BBLR interactions in the LHC. During this campaign, a proof-of-concept was completed and motivated an additional set of experiments, successfully demonstrating the mitigation of BBLR interactions effects in beam conditions compatible with the operational configuration. This paper reports in detail the preparation of the experimental campaign, including the corresponding tracking simulations and the obtained results, and draws some perspectives for the future.