Accelerator Report: A very busy technical stop ahead of Long Shutdown 3

This technical stop is particularly intense, being both shorter than usual, to maximise the limited time for physics, and very busy, to make essential preparations for LS3, which begins in June

The accelerator complex delivered its last beams of 2025 on 8 December before beginning the year-end technical stop (YETS). During a technical stop, the responsibility for accelerator coordination is passed to the Engineering department’s Accelerator Coordination and Engineering group (EN-ACE) to oversee the many interventions planned in the accelerator complex.

This YETS has been particularly intense, being both shorter than usual, to maximise the limited time for physics in 2026, and very busy, to make essential preparations for Long Shutdown 3 (LS3), which begins in late June (for the LHC) and late August (for the rest of the complex). At times, more than 500 people per day have been accessing the underground complex.