Tracker outer barrel (TOB) module from the CMS tracker

One of the building blocks of the CMS Silicon Tracker: a part of the detector that reconstructs the trajectories of charge particles emerging from the proton-proton collisions. A lightweight structure, made mostly of carbon fibre, supports silicon detectors and their readout electronics. These detectors generate an electrical pulse when they are traversed by a charged particle, and they are segmented into fine strips (in this case the strips are 180 microns wide, about the size of a human hair) that collect those pulses, such that the position of the strip provides a coordinate on the particle trajectory.