Researchers from the University of Zurich Physics Institute, led by Prof. Florencia Canelli and Prof. Ben Kilminster, are excited today as a sophisticated detector they helped produce is installed in the heart of a mammoth, 15-meter diameter experiment at the Large Hadron Collider at CERN. The big experiment is CMS (Compact Muon Solenoid), and consists of a range of detector systems designed to detect all the known quantum particles and forces of the universe, including the newly-discovered Higgs boson. Their new detector, called the "barrel pixel" detector, is a 30-centimeter diameter cylinder with the capability of recording billions of proton interactions per second.
Prof. Kilminster explains, "The goal of CMS is to find the breaking point of the laws of physics. The new barrel pixel detector makes precise measurements of particles that exist for only 0.000 000 000 001 second, and could help reveal the point at which our current set of equations that transform matter and energy no longer work."
Smallest but most important
Although the barrel pixel detector is the smallest detector in CMS, it produces most of the measurements. Every time protons cross in CMS, a hundred million pixels are checked for the tell-tale sign of charged particles traveling through. As Prof. Canelli describes, "the barrel pixel detector is like a camera with a 100 Mpixels that takes 40 million photos per second." The new detector provides CMS with improved capabilities in handling the intense data rates being provided by the LHC, and reconstructs the trajectory of the hundreds of charged particles produced in each proton collision with precisions down to 10 micrometers. Such particles can be the telltale sign of new phenomena such as extra dimensions or forces.
The UZH group has assembled and tested the system for controlling and powering the detector sensors, reading out the high rate data, and cooling the detector and electronics. This work has been done by PhD students, post docs, scientists, and engineers and technicians from the Physics Institute over the last 5 years. Four system cylinders, filled with hundreds of electronics components and laser drivers, have been built, and precisely tested so that the 100 million detector channels will perform properly and be synchronized down to the nanosecond.
The new barrel pixel detector will be essential in helping the CMS experiment uncover the possible breaking point of the laws of physics over the next decade.