Crystal collimation was successfully integrated in the WP5 upgrade baseline as an in-kind item to mitigate schedule issues with the 11 T dipoles which have shown potential reliability issues for long-term operation in the accelerator
The Hollow Electron Lens (HEL) will provide, by means of a hollow electron beam overlapping over about 3 m length with the HL-LHC hadron beam, an active way to enhance particle diffusion and controlled depletion of the hadron beams tails.
The two RF dipole crab (RFD) cavities being prototyped for the SPS tests underwent an ultra-pure water rinsing for a period of approximately 7 hours at very high pressure of 100 bar.
After the successful tests of MQXFA03 and MQXFA04, that allowed last year to obtain the approval of the US contribution by the DOE, MQXFA05 has been tested in May 2021.
The performance ramp-up of the LHC after LS3 foresees a smooth ramp-up of the effective pile-up density for the nominal case, with a nominal bunch intensity reached after two years.
The HL-LHC Technical Coordination Committee has continued its work for the follow-up and evolution of the technical baseline of the project in a fully remote format.
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.
Following a very successful exercise in 2021, CERNs Council has requested the Cost & schedule reviews of the HL-LHC project to be held annually, a lighter edition alternating every second year with a full project review.
