New protection scheme and pressure relief-valve staging of the LHC insulation vacuum enclosure following the 19th September 2008 incident

This note defines the new protection scheme and the pressure relief valve staging of the LHC insulation vacuum enclosure which has to be implemented following the 19th September 2008 incident in the Sector 3-4. This note covers all the equipment located in the arcs, dispersion suppressors, matching sections and inner-triplets, including the QRL cryogenic line. As part of the machine will not be consolidated until the long shutdown scheduled after the first LHC operation years, a temporary protection scheme is also defined allowing a safe LHC operation at reduced beam energy.