The LHC sectors are cooled by eight similar helium refrigerators. P4 needs more cooling capacity due to the superconducting RF. This has not limited LHC so far but would be a bottleneck for the HL-LHC era.
Today’s LHC environment is subject to different radiation types, particle types and energy ranges. In particular, at the machine-experiment regions the main sources of radiation come from beam collisions at experiments and beam interactions.
The progress since the last collaboration meeting in October 2021 has been impressive and the project passed several key milestones for the project implementation in spite of the turbulences caused by Covid-19 and the crisis in Ukraine.
An important milestone was achieved in June 2020 with the successful test at CERN of a demonstrator of the cold powering system for the HL-LHC magnets. Demo 2 incorporates a superconducting 60-m long power transmission line, the Superconducting Link.
Two prototypes of RF dipole cavities which provide horizontal crabbing for the HL-LHC were successfully built at CERN. The frequency tuning setup before the final two welds is shown in the figure below.
The most significant advancement has been the test of the third US-AUP full size magnet (MQXFA03). It reached nominal gradient with limited training and is the first magnet ready to be included in the first cold mass to be installed in the IT-String test.
The COVID-19 restrictions have impacted the schedules of the LS2 and of the HL-LHC activities. Concerning the LS2 schedule, the hardware commissioning of LHC should be completed by March 2021 for all sectors except the S67.
WP17 Infrastructure, Logistics and Civil Engineering
The 4th Cost & Schedule Review (CSR) of the HL-LHC project was held at CERN from 11 to 13 November 2019. The review panel was composed as usual by CERN Machine Advisory Committee (CMAC) members and ad-hoc experts.
After having observed the first cases of illness in Italy and the following isolation measures, the coronavirus SARS-Cov-2, causing the severe respiratory illness COVID-19, became a subject of major concern in Europe during February 2020.
