Speaker
Description
Cathode Strip Chambers (CSC) provide precise measurements of muon track coordinates in the CMS endcap region. CSC uses 40%Ar+50%CO2+10%CF4 as a working gas mixture, where the CF4 component provides reliable protection against anode wire aging sufficient for CSC operation during the HL-LHC period. However, CF4 has a Global Warming Potential (GWP) of 6630 over 100 years, so the CMS CSC community is searching for a way of either lowering the fraction of CF4 in or excluding it entirely from the CSC gas mixture.
Measurements of the performance and longevity capability of various gas mixtures are primarily done with small CSC prototypes constructed with the original CSC materials strictly following the production technology. Long-term irradiation tests are ongoing at the Gamma Irradiation Facility (GIF++) at CERN with large original CSC chambers.
