August 23, 2017 – The world’s most powerful particle accelerator, the Large Hadron Collider (LHC), began running at CERN, the European Organization for Nuclear Research, in 2009. The LHC spends most of its time studying the puzzles of high-energy physics. But for one month a year, it, like the Relativistic Heavy Ion Collider (RHIC) at the U.S. Department of Energy’s (DOE’s) Brookhaven National Laboratory in New York, studies the nuclear physics of the early universe by colliding heavy, charged nuclei (ions). As first demonstrated at RHIC, tiny samples of the quark–gluon plasma (QGP), the matter that permeated the entire universe in its infancy, are produced in high-energy, heavy-ion collisions. The heavy-ion program at the LHC subsequently confirmed RHIC’s discovery of the QGP and now enables the study of the QGP from vastly different initial conditions than those produced at RHIC. Thus, the results from LHC complement the U.S.-based RHIC program by allowing scientists to study this unique state of matter under the widest possible range of conditions.
An experiment at the LHC is dedicated to the study of heavy-ion collisions. Called ALICE, it is the only experiment there dedicated entirely to the study of the nuclear physics of the QGP. ALICE stands for “A Large Ion Collider Experiment.” Its aim is spotting the high-energy, elementary particles, like electrons and gamma rays, streaming from the QGP, to explore the physics of the early universe. Funded by 58 agencies worldwide, including the DOE Office of Science, ALICE connects approximately 1,800 researchers from 174 institutes in 42 countries. They depend on the dozen instruments that constitute ALICE, including an electromagnetic calorimeter operated by DOE’s Oak Ridge National Laboratory, to study—in the laboratory—conditions like those right after the Big Bang.
Work on ALICE to date has inspired 405 student theses (completed or in process worldwide); U.S. doctorates number about 20.
ORNL physicist Thomas M. Cormier leads the international group responsible for the calorimeter and the ongoing upgrade of ALICE’s time projection chamber for LHC’s third run. In 2013, he came to ORNL from Wayne State University, where he held a joint appointment at Lawrence Berkeley National Laboratory, to head the Large Hadron Collider Heavy Ion Group and lead the design, development and deployment of future U.S. instrumentation for ALICE.
In the full interview with ORNL’s Dawn Levy (click here to read), Cormier provides an update on ALICE and discusses how the experiment is on track to produce 3 terabytes of data per second starting in 2021. “In very few seconds you produce more data than anybody has ever stored, from anything,” he observes.
Source: Oak Ridge National Laboratory