During the week of March 19, the CMS endcap muon upgrade passed a major milestone, with the completion of the certification of the final 36 Cathode Strip Chambers (CSC) for reinstallation on the CMS detector. The 72 chambers comprising the first layer of the CSC detector were extracted last summer and moved to the CSC refurbishment and testing facility located on the surface 100 m above CMS. Following this extraction, the on-chamber electronics that collect electrical signals produced as muons traverse the chambers were dismounted and replaced with upgraded versions. The improved capabilities of the new electronics will ensure that CMS continues to efficiently identify muons in the endcap regions under the harsher operating conditions of the post-LS1 LHC.

After being equipped with the new electronics, each chamber was subjected to a comprehensive suite of tests to confirm basic functionality including a data quality assessment using cosmic ray data. The refurbishment and testing of each chamber was performed by a group of postdocs, engineers, and students in collaboration with CSC experts.
The first 36 chambers of the +z endcap completed testing in November of last year, and after reinstallation, have since completed a successful commissioning. The 36 chambers of the -z endcap have now been cleared for reinstallation which is expected to be completed by mid-April.

Shalhout Shalhout