Simulation of beam-beam induced emittance growth in the HL-LHC with crab cavities

TL;DR

This paper uses computer simulations to study how beam-beam effects and crab cavities influence emittance growth in the HL-LHC, highlighting the importance of working point adjustments.

Contribution

It presents a detailed simulation model for emittance growth in HL-LHC considering beam-beam effects and crab cavities, and evaluates the impact of working point tuning.

Findings

Large beam-beam tune shift causes resonance and emittance growth.

Adjusting the working point reduces emittance growth.

Simulations align with expected HL-LHC beam parameters.

Abstract

The emittance growth in the HL-LHC due to beam-beam effects is examined by virtue of strong-strong computer simulations. A model of the transverse damper and the noise level have been tuned to simulate the emittance growth in the present LHC. Simulations with projected HL-LHC beam parameters and crab cavities are discussed. It is shown that with the nominal working point, the large beam-beam tune shift moves the beam into a resonance that causes substantial emittance growth. Increasing the working point slightly is demonstrated to be very beneficial.