Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation

TL;DR

This paper investigates beam losses caused by electromagnetic interactions during Pb ion collisions at the LHC, quantifies their impact on magnet quenching, and explores mitigation strategies to improve collider performance.

Contribution

It introduces a comprehensive simulation approach to quantify beam losses and their effects, and discusses potential methods for monitoring and alleviating these losses.

Findings

Heat load during Pb operation exceeds quench threshold by 40%

Simulation predicts limitations on maximum achievable luminosity

Proposes monitoring and mitigation strategies for beam losses

Abstract

Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of Pb ion operation in the LHC, with focus on the ALICE interaction region, and show that the expected heat load during nominal Pb operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.