CMS tracking detector successfully installed

December 18, 2007
CMS tracking detector successfully installed
Installation of the world's largest silicon tracking detector in the CMS experiment at CERN.

Installation of the world’s largest silicon tracking detector was today successfully completed at CERN. In the early hours of Thursday 13 December the CMS Silicon Strip Tracking Detector began its journey from the main CERN site to the CMS experimental facility. Later that day it was lowered 90 metres into the CMS cavern. Installation began on Saturday 15 December and was concluded this morning.

“This achievement completes the installation of sub-detectors inside the CMS magnet, which was lowered into the cavern on 28 February,” said CMS technical coordinator Austin Ball. “It’s a big milestone for us.”

With a total surface area of 205 square metres, about the same as a singles tennis court, the CMS Silicon Strip Tracking Detector is by far the largest semiconductor silicon detector ever constructed. Its silicon sensors are patterned to provide a total of 10 million individual sensing strips, each of which is read out by one of 80,000 custom designed microelectronics chips. Data are then transported via 40,000 optical fibres into the CMS data acquisition system.

“The complete system operating at the LHC will produce data at a higher rate than the entire global telephone system,” said project manager Peter Sharp.

The silicon sensors are precision mounted onto 15,200 modules that are in turn mounted onto a very low mass carbon fibre structure that maintains the position of the sensors to less than the diameter of a human hair (100 microns).

“Each of the charged particles produced in LHC particle collisions at the heart of the CMS detector will be tracked with a precision of better than 20 microns,” said Sharp.

Final assembly of the silicon tracking detector began in December 2006 and was completed in March 2007. All of the systems were then fully commissioned, with 20% of the full detector operated over several months during which five million cosmic ray tracks were recorded. The results from these data were then rapidly analyzed using the CMS Grid-based distributed computing system. This commissioning demonstrated that the detector fully meets the experiment’s requirements.

“Constructing a scientific instrument of this size and complexity, designed to operate at the LHC without intervention for more than ten years, is a major engineering and scientific achievement,” said CMS spokesman Tejinder Virdee. “More than five hundred scientists and engineers from fifty-one research institutions world-wide have contributed to the success of the project.”

Institutions involved in the CMS tracker project are located in Austria, Belgium, CERN, Finland, France, Germany, Italy, Switzerland, the United Kingdom and the United States.

CMS is a worldwide collaboration comprising over 2500 scientists and engineers from 180 institutes in 38 countries and regions. These are Armenia, Austria, Belarus, Belgium, Brazil, Bulgaria, China, Colombia, Croatia, Cyprus, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, India, Iran, Ireland, Italy, Korea, Lithuania, Mexico, New Zealand, Pakistan, Poland, Portugal, Russian Federation, Serbia, Spain, Switzerland, Taiwan, Turkey, Ukraine, United Kingdom, United States of America and Uzbekistan.

Source: CERN

Explore further: First physics from the Large Hadron Collider's CMS detector

Related Stories

First physics from the Large Hadron Collider's CMS detector

February 17, 2010

( -- Scientists working on the CMS experiment at the CERN LHC have just published results of the first analysis of data from the highest energy particle collisions ever carried out, bringing us another step closer ...

The midnight ride of the CMS tracking detector

December 20, 2007

Scientists of the U.S. CMS collaboration today (Dec. 20) joined colleagues around the world in announcing the successful installation of the world's largest silicon tracking detector at CERN in Geneva, Switzerland. Just before ...

Making synthetic diamond crystals in a plasma reactor

March 21, 2014

Synthetic diamond crystals are of interest to many industrial sectors. Their unique properties make them a suitable material for numerous applications including lenses for high-energy laser optics, X-ray radiation detectors ...

CERN latest data shows no sign of supersymmetry – yet

July 25, 2013

Physicists at Liverpool played a significant role in the development of the VErtex LOcator (VELO), a precision silicon detector, at the core of LHCb. The VELO detector consists of 42 separate modules (shown here), which were ...

Understanding what's up with the Higgs boson

June 28, 2012

( -- CERN, the European Organization for Nuclear Research headquartered in Geneva, Switzerland, will hold a seminar early in the morning on July 4 to announce the latest results from ATLAS and CMS, two major experiments ...

Recommended for you

Exploring the physics of a chocolate fountain

November 24, 2015

A mathematics student has worked out the secrets of how chocolate behaves in a chocolate fountain, answering the age-old question of why the falling 'curtain' of chocolate surprisingly pulls inwards rather than going straight ...

SLAC theorist explains quantum gravity

November 19, 2015

Our world is ruled by four fundamental forces: the gravitational pull of massive objects, the electromagnetic interaction between electric charges, the strong nuclear interaction holding atomic nuclei together and the weak ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.