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.
The progress since the last collaboration meeting in October 2020 has been truly remarkable and the project successfully passed several key milestones for the project implementation in spite of the COVID-19 restrictions.
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.
The High-Luminosity Project is nowadays in the transition from the prototyping phase into full construction mode and most of the activities in view of the series production for the HL-LHC hardware have already started.
