World’s biggest particle accelerator will benefit Rice researchers

World’s biggest particle accelerator will benefit Rice researchers

BY B.J. ALMOND
Rice News Staff   
 
The world’s largest silicon tracking detector was installed successfully at CERN in Geneva, Switzerland, this week, and Rice physicists Paul Padley and Jabus Roberts couldn’t be happier.

“This is a crucial component of the biggest science experiment ever built, and Rice students and faculty will benefit from it,” said Padley, associate professor of physics and astronomy at Rice. He and Roberts, professor of physics and astronomy, are working on complementary components of the experiment.

After lowering the sealed tracker into the experiment hall, the CMS team prepares to lift it into the detector. MICHAEL HOCH ADVENTURE ART

The six-ton CMS Silicon Strip Tracking Detector is part of the world’s largest particle accelerator. It had to be transported from the main CERN site in Geneva to the Large Hadron Collider (LHC) particle accelerator — a 10-mile, three-hour journey.  CERN is the European Organization for Nuclear Research — Europe’s main particle-physics laboratory.

Physicists from the U.S. built and tested 135 of the 205 square meters of the Silicon Strip Tracking Detector. With an area about the size of a singles tennis court, it is the largest semiconductor silicon detector ever constructed. Its sensors are patterned to provide a total of 10 million individual sensing strips, each read out by one of 80,000 custom-designed microelectronics chips. Forty thousand optical fibers then transport data into the CMS data acquisition system. CMS stands for Compact Muon Solenoid.

Of the CMS collaboration’s approximately 2,300 physicists, about 500 are U.S. scientists from more than 45 U.S. universities — including Rice — and Fermilab, supported by the Department of Energy and the National Science Foundation.

Although Rice scientists weren’t involved directly on the silicon tracking detector that was installed this week, they are working on other components of the mammoth project. The various components will be added to the silicon tracking detector like pieces of a huge puzzle.

“Half of what we’ve been working on is in place, and the other half will go in this winter,” Padley said.

He and Roberts have helped design and construct the muon detector in the giant Compact Muon Solenoid at the LHC. Padley was chosen to lead the scientific operations of a piece of the detector built by U.S. institutions. Roberts has spent several summers at CERN working with Rice students and engineers who are installing the experiment.

Padley described the whole project as “the Holy Grail of particle physics,” noting that students and faculty at Rice will be able to collect data from it, analyze the information and better understand the universe.

“The universe appears to be mostly dark matter and dark energy, and we don’t know what that is,” Padley said. “Starting next year, we should be able to obtain particle physics results that will enable us to figure out the composition of the universe.”

In addition to Rice, two other U.S. CMS member institutions are in Texas: Texas A&M University and Texas Tech University.