October 4, 1999
UPTON, NY - U.S. Energy Secretary Bill Richardson today celebrated
the commissioning of the Relativistic Heavy Ion Collider (RHIC)
at the department's Brookhaven National Laboratory. RHIC is the
world's newest and biggest particle accelerator for nuclear physics
"This is a remarkable moment for science," Secretary Richardson said. "This new accelerator, which was completed on schedule and on budget, will be the only place in the world where researchers can do this kind of physics."
RHIC is a particle accelerator that will collide heavy ions - atoms stripped of electrons, from heavy elements such as gold - traveling in opposite directions at nearly the speed of light. In those collisions, physicists hope to recreate conditions that last existed millionths of a second after the Big Bang, when the universe was born.
"We at Brookhaven are thrilled to present to the international science community a world-class facility for the 21st century," said Brookhaven Laboratory Director John Marburger.
Scientists believe that protons and neutrons are made up of three particles known as quarks, along with the gluons that bind them together. Scientific theory holds that for a brief time at the beginning of the universe there were no protons and neutrons, only free quarks and gluons. As the universe expanded and cooled, however, the quarks and gluons bound together and since then have remained virtually inseparable. RHIC's goal is to free the quarks and gluons from their confinement in the nucleus, to create a quark-gluon plasma. This rare state of matter has never been seen before, and it offers physicists an exciting new area of scientific study. The information found at RHIC can be applied in nuclear physics (the study of the atom), particle physics (the study of the atom's parts), astrophysics (the study of stars and planets), condensed matter physics (the science of solid matter) and cosmology (the study of the universe).
The RHIC Complex
RHIC construction began in 1991, and the project was completed this year. During a commissioning period, all parts of the machine were tested and operated as a complete system. Construction and commissioning costs totaled $600 million.
In RHIC, two beams of heavy ions will whiz around in opposite directions at energies called "relativistic," because they approach the speed of light. At these speeds, Einstein's theory of relativity is required to describe the motion.
The ions will travel through a pair of rings in a tunnel 3.8 kilometers (2.4 miles) in circumference. When the beams collide, each collision will liberate up to 36 trillion electron volts in energy in a very small volume, about the size of an atomic nucleus. This enormous energy density will create new matter at a temperature ten thousand times that of the sun. Such conditions are the key to creating a quark-gluon plasma. This cannot be done at existing accelerator facilities anywhere else in the world.
RHIC is actually the newest and final link in a chain of accelerators that makes up the RHIC accelerator complex. Heavy ions destined for RHIC originate in the laboratory's Tandem Van de Graaff, proceed into the Booster, and then into the Alternating Gradient Synchrotron (AGS); all three were pre-existing facilities at the laboratory. The AGS will inject heavy ions into RHIC for experiments.
When RHIC is operating, over 100 bunches of heavy ions will be injected into each of the two rings. Then, with both rings filled, the ions will be accelerated in minutes to the top energy. At that energy, the ion beams will coast around the rings in stable orbits for hours. For experiments, particles will be collided head-on at the rate of tens of thousands of collisions per second.
International Collaboration on RHIC Experiments
The tunnel configuration provides for six areas where the circulating beams cross and collisions take place. Four areas now contain apparatus, called detectors, for electronically recording the results of the interactions between particles.
Large collaborations of researchers built the four detectors. All together, close to 1,000 scientists from 90 research institutions representing 19 countries will be working on RHIC experiments.
Two giant detectors, called STAR and PHENIX, are among the most complex ever built. The two smaller detectors are known as PHOBOS and BRAHMS.
Industrial Partnership in RHIC Construction
Principle RHIC components were manufactured by industry, in some cases through cooperative ventures that transferred technology developed at Brookhaven Laboratory to private industry.
The RHIC tunnel is filled with two sets of superconducting magnets strung together like beads on a necklace. The 1,740 superconducting magnets bend and focus the particles as they speed around the rings. The dipole and quadrupole magnets were built by Northrop-Grumman Corporation, on Long Island, and the sextupole magnets were built by Everson Electric, in Bethlehem, PA. Brookhaven Laboratory built the corrector magnets and other special magnets.
All RHIC magnets use superconducting cable, which is made from niobium-titanium alloy filament, a special material that loses electrical resistance at a temperature close to absolute zero (minus 459 degrees Fahrenheit). Partnering in superconducting cable production were: Oxford Superconducting Technology, headquartered in Carteret, New Jersey; Furukawa Electric, of Nikko, Japan; and New England Electric Wire, Lisbon, New Hampshire.
RHIC conventional construction was completed by Seacrest Construction, Carter-Melence, Dayton Construction, Frendolph, J.F. O'Healy, Hinck, Seaman, and McDowell, all Long Island-based companies.
Gardner Cryogenics, of Lehigh Valley, PA, worked on the cryogenic cooling system. Precision Components, in York, PA, manufactured parts for the PHENIX detector.
RHIC Operating Schedule
RHIC commissioning ended this past August, and the four detectors are being readied for RHIC operation. The collider will be brought into operation in stages. The two rings of magnets will first be cooled down to 4.5 degrees above absolute zero (minus 452 degrees Fahrenheit). Gold ions will be circulated in opposite directions in each of the two rings. Next, the ion beams will be collided at low energies. Then, the beam energies will be steadily increased until the machine is ready for collisions at high energies. RHIC will operate for physics experiments in early 2000.
Additional information on RHIC, including graphics and animation, is available on the World Wide Web at http://www.rhic.bnl.gov/
The U.S. Department of Energy's
Brookhaven National Laboratory creates and operates major facilities
available to university, industrial and government personnel for
basic and applied research in the physical, biomedical and environmental
sciences, and in selected energy technologies. The Laboratory
is operated by Brookhaven Science Associates, a not-for-profit
research management company, under contract with the U.S. Department