Recommissioning of the COLDEX Experiment at CERN

COLDEX (Cold bore Experiment), installed in the Super Proton Synchrotron (SPS) at CERN, is a test vacuum sector used in 2001-2004 to validate the Large Hadron Collider (LHC) cryogenic vacuum system with LHC type proton beams. Its cryostat houses a 2.2 m long copper perforated beam screen surrounded by a stainless steel cold bore, both individually temperature controlled down to 5 and 3 K, respectively. In the framework of the development for the High Luminosity upgrade of the LHC (HL-LHC), COLDEX has been re-commissioned in 2014. The objective of this re-commissioning is the validation of the performance of amorphous carbon coatings at cryogenic temperature with LHC type beams. The existing COLDEX beam screen has been dismounted and carbon coated, while a complete overhaul of the vacuum, cryogenic and control systems has been carried out. This contribution describes the phases of re-commissioning and reviews the current experimental set-up. An overview of the possible measurements with COLDEX, in view of its HL-LHC experimental program, is also presented.