Groundbreaking calorimeter for the #HiLumiLHC The @cmsexperiment has recently completed the first prototype slice of its innovative High-Granularity Calorimeter (HGCAL), which will be the largest silicon-based detector ever built. Scientists from all over the world are contributing to the first complete prototype of a wedge-shaped slice of the new CMS endcap calorimeter. This slice – shown in the video – is known as a “cassette” and is being built in a clean room at the CMS experiment site. Read