Optimisation of integrated luminosity in a circular collider with application to the LHC Run 2

Circular collider designs are tailored to maximise luminosity delivered to experimental detectors, effectively utilising the charged beams that have been accelerated for collisions. In reality, the key metric for the effective operation of a circular collider is the integrated luminosity provided to the experiments, which can significantly differ from the theoretical capability regarding instantaneous luminosity of the accelerator. Several factors influence the collection of integrated luminosity, with the most critical being the duration of each physics fill. This paper presents and examines strategies for determining optimal fill durations based on actual fill conditions, applying these methods to public luminosity data measured by the ATLAS detector during the LHC Run~2, covering the physics runs from 2016 to 2018.