Assembly of a Ti helium vessel on a HL-LHC DQW Crab Cavity

Superconducting radio frequency crab cavities are essential components for the High-Luminosity LHC project. The crab cavities will help increase the luminosity reach by restoring head-collisions at the interaction points. Two types of cavities are required, the Double Quarter-Wave (DQW) and the Radio Frequency Dipole (RFD), designed to compensate vertical (CMS) and horizontal (ATLAS) crossing angles respectively. While the prototyping phase of the project is being finalized, series production of cavities and auxiliary systems has started. The target is to complete the construction and installation of eight cryomodules in the LHC during the Long Shutdown 3. The crab cavity project is a worldwide endeavour: in addition to CERN deliverables, major contributions from industrial partners and international collaborations are expected throughout the project. On these pictures, a titanium grade 2 helium vessel is being TIG welded around a Double-Quarter Wave LHC Crab Cavity, inside a glovebox at CERN EN-MME Main Workshop. This cavity, fully manufactured at CERN, will then be tested at the SM18 SRF facility and connected in a cleanroom with its twin (manufactured in 2022) before their installation in the first LHC DQW cryomodule.