Energy Frontier

Fermilab's Contribution to Accelerator & Detector Technology at the LHC


Fermilab, in collaboration with CERN and the KEK laboratory in Japan, designed and constructed the inner triplet magnet systems that focus the proton beams just before they enter the four main LHC experiments to increase their chances of colliding.

Fermilab and Lawrence Berkeley National Laboratory designed and constructed eight cryogenic and power-feed boxes that support the final-focus systems. Scientists from Fermilab also helped carry out accelerator physics calculations in support of the design of the LHC. Fermilab has contributed to the design of equipment to improve performance of the LHC and to the commissioning of the collider.


Hadron calorimeter and electromagnet calorimeter

Fermilab scientists, technicians and engineers helped lead the international team that designed, constructed and tested the CMS detector’s hadron calorimeter, a device that measures the energy and direction of particles that interact with strong force. Researchers associated with Fermilab also contributed to the barrel electromagnetic calorimeter that forms a cylinder surrounding the point where particle beams meet in the detector. The electromagnetic calorimeter measures the energy and position of photons and electrons.

Muon detector

Fermilab took part in building one subset of the large muon detector system, which identifies some of the heaviest particles to result from proton beam collisions , muons. Muon identification uses a type of detector called Cathode Strip Chambers, a gas detector that simultaneously reads out information about muon positions in two dimensions. The CMS detector contains 468 of these detectors, organized into eight wheels 10 meters in diameter.

Silicon strip tracking system

Scientists, technicians and engineers from Fermilab helped construct a particle-tracking system made entirely of more than 200 square meters of silicon detectors. It is the largest silicon strip detector ever constructed. U.S. collaborators, including Fermilab, built about two-thirds of the surface area of the detector. They constructed all 5,200 modules for the Tracker Outer Barrel section of the system and assembled them into rods.

Forward pixel tracking system

Fermilab technical scientific staff also helped build more than 2,000 modules for the Tracker Endcap. The endcap, a highly segmented silicon pixel detector, operates about 20 centimeters from the beams. The density of particles emitted from the collisions is very high that close to the beams. Tracking particles in this region must have high precision to determine whether particles come from the main interaction or from decays that happen a very small distance away. U.S. collaborators, including those from Fermilab, led the project to build the endcap, which consists of 18 million silicon pixels that measure 100 by 150 millimeters squared.

Trigger system and data acquisition

At full luminosity, the LHC beams will produce 1 billion interactions per second in the center of the CMS detector. The trigger system selects about 100 of these events as promising indicators of new physics beyond the Standard Model. Fermilab and other U.S. groups played a leadership role in developing hardware for the lowest level of the trigger selection project, which must examine every collision and therefore must operate at the highest speed. U.S. scientists, including Fermilab researchers, developed the hardware and software to coordinate the flow of events in the data acquisition system and to bring event data from the underground enclosure that houses the experiment to the surface where the events are recorded.

Last modified: 04/27/2009 |