Sept. 10, 2008
UI researchers celebrate start-up of world's largest particle accelerator
If you are reading this story, then the world has not come to an end.
Rather, physicists around the world are celebrating the Sept. 10 completion and start-up of the world's largest atom smasher: the $8 billion Large Hadron Collider particle accelerator at CERN in Geneva, Switzerland.
Scientists will first calibrate the machine, using its powerful magnets to accelerate two beams of protons so that they race around a 16.5-mile oval track in opposite directions without colliding.
But when the proton collisions begin some weeks from now, scientists will have the ability to gradually increase the energies of the opposing proton beams to nearly seven trillion electron volts (TeV) each, about seven times the power of the next-most-powerful machine located at Fermilab near Chicago.
All the excitement is centered on the fact that nobody really knows what will happen. Some pundits, including a few scientists, have worried that the collider's enormous power will create a small black hole capable of eating everything in its path, including the Earth. But most scientists have noted that the collider poses no danger and that it will allow researchers to continue searching for the basic building blocks of matter as well as answer questions about how the universe is constructed.
Yasar Onel, professor of physics in the UI College of Liberal Arts and Sciences, said that the instrument is essential to the advancement of particle physics research and that the University of Iowa can take pride in its completion.
"I am very excited after 14 years of planning, constructing the detectors and preparing the physics analysis methods," said Onel, who, together with six other UI researchers will be at CERN for the LHC start-up.
In particular, the UI contribution to the project is a particle detector called the "subdetector HF-Forward Calorimetry device." Designed and developed at UI machine shops, it became the first detector to go underground in the Compact Muon Solenoid (CMS) collision hall in November 2007. In order to help install the equipment, the UI has had two research associates and one senior engineer living in Geneva, Switzerland, for more than three years.
The UI CMS team includes Onel, Associate Professors Jane Nachtman and Charles Newsom, Emeritus Professors Ed Norbeck and Ed McCliment, and Project Scientist J.P. Merlo. Onel also serves as Photodetector Project Manager and Calorimetry Upgrade Coordinator for Super-LHC, and Newsom is involved in the Pixel Tracking detector.
The UI group also includes UI engineers Paul Debbins, Mike Miller and Ianos Schmidt as well as UI postdoctoral fellows U. Akgun, Kerem Cankocak, K. Chung, Alexi Mestvirishvili, Lalith Perera, Taylan Yetkin and K. Yi. There are also six graduate students on the team: Elif Albayrak, Burak Bilki, Warren Clarida, Anthony Moeller, Ferhat Ozok and James Wetzel.
In addition to Onel's research group, a group of UI researchers -- led by Usha Mallik, professor of physics in CLAS -- is working on the Large Hadron Collider. Mallik's group is working on the seven-story-tall ATLAS (A Toroidal LHC ApparatuS) particle detector in the underground collision hall of the LHC.
Like CMS, the ATLAS experiment is designed to observe phenomena that involve highly massive particles which were not seen using older, lower-energy accelerators.
Mallik and her group of UI scientists, all of whom are currently at CERN, include: Prafulla Behera, assistant research scientist, and Alexander Schreiner, postdoctoral student.
Said Mallik: "We are all involved in commissioning the ATLAS pixel detector. Specifically, Behera is responsible for the monitoring of the Pixel Detector Control system and the high-level trigger for Minimum Bias Events. Schreiner is working on the Pixel Data Acquisition system in the coding of the Digital Signal Processors (DSP)."
A total of 38 U.S. universities are participating in the ATLAS experiment, a collaboration consisting of 2,100 people from more than 30 countries.
The UI forward calorimeter will measure the energy of particles moving in a forward direction after the proton collision has taken place at the center of a total energy mass of 14 trillion electron volts (TeV) -- enough energy to replicate, in miniature, conditions present shortly after the creation of the universe. The calorimeter's quartz fibers give off light when struck by particles released by the proton collisions.
"We are opening a new energy frontier," said Nachtman. "We will create new particles which may help to answer fundamental questions about the universe."
Onel pointed out that scientists won't see the actual particles. By measuring the light they give off, researchers will know the particles are present. He added that atoms are composed of electrons and nuclei, and nuclei are made up of protons and neutrons. Neutrons, in turn, are constructed of quarks, but that is currently the extent of mankind's knowledge.
Onel said that quarks and electrons may turn out to be the fundamental building blocks of nature, or they may be composed of something even more basic. Researchers also say the LHC may allow them to make fundamental discoveries about the universe, understand the behavior of certain particles, discover the origins of mass, shed light on dark matter, uncover hidden symmetries of the universe, and possibly find extra dimensions of space.
About one-third of the 1,500 CMS physicists are U.S. scientists who work through the U.S. Department of Energy's Fermi National Accelerator Laboratory in Batavia, Ill.
STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500.
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