The quest to understand the mysteries of the universe took another step forward today as the final pieces of the so-called “Big Bang Machine” were lowered into place at the CERN laboratory in Geneva, Switzerland. With the installation of two 100-tonne “small wheels” that are the last components of the muon spectrometer, the ATLAS detector is now virtually complete – much to the excitement of a University of Regina scientist who has been involved with the project for the better part of a decade.

“The installation of the ‘small wheels’ symbolizes the end of the construction phase of the ATLAS detector,” said Kamal Benslama, a physics professor at the U of R. “More importantly, however, it represents the beginning of a new era of data collection and analysis that will help explain the origin of the universe and the nature of matter. It will be a new era in which the University of Regina can expect to play a significant role.”

Benslama co-ordinates the University of Regina’s participation in the ATLAS project, which is the largest experiment in the history of the physical sciences. The experiment involves 35 countries, 178 institutions and close to 2,500 scientists. It is based at the Large Hadron Collider (LHC), a new particle accelerator located at CERN – the world’s largest particle physics laboratory. The $9.5 billion LHC is located 100 metres underground in a 16-mile long circular tunnel which runs under the Franco-Swiss border.

Inside the LHC tunnel, two particle beams will be accelerated to extremely high energies, and then crashed into each other forty million times per second. The resulting conditions will correspond to those which existed approximately 1/10,000,000,000 of a second after the “Big Bang,” when the temperature was 1,000,000,000,000,000 degrees Celsius. The 7,000 tonne ATLAS detector will electronically register these conditions, allowing physicists to analyze the reactions that created them.

The U of R ATLAS team – consisting of Benslama, his students and his postdoctoral fellows – has worked specifically on the Liquid Argon Calorimeter and High Level Trigger components of the ATLAS detector. As one of the 11 Canadian institutions collaborating on the multinational project, the U of R will have special access to the data collected through ATLAS.

The installation of the “small wheels” marks the end of a decade of development and planning for the muon spectrometer system. Comprising 450 physicists from 48 institutions, the ATLAS muon system includes members from Armenia, Belgium, China, Czech Republic, France, Germany, Greece, Israel, Italy, Japan, Netherlands, Pakistan, Russia, Serbia, Slovac Republic, Spain, Sweden, and the United States of America.

With the detector’s construction virtually complete, the ATLAS collaboration will focus now on commissioning work in preparation for the start-up of the LHC this summer. Experiments at the LHC will allow physicists to take a big leap on a journey that started with Newton’s description of gravity. Gravity is ubiquitous since it acts on mass, but so far science is unable to explain why certain particles have the masses they have. Experiments such as ATLAS may provide the answer. LHC experiments will also probe the mysterious missing mass in the Universe, investigate the reason for nature’s preference for matter over antimatter, probe matter as it existed close to the beginning of time, and look for extra dimensions of space-time.

“At the University of Regina, we are very excited about the impending start-up of the ATLAS detector,” says Katherine Bergman, Dean of Science at the U of R. “Once data begins to be collected and analyzed, our ATLAS team could be participating in discoveries that will change the field of physics significantly, altering the way we view the world around us. This is a once-in-a-lifetime opportunity for our physics students and faculty.”

Further information about the ATLAS project, including video and virtual tours, can be found at http://atlasexperiment.org/