For release: June 15, 1998
Contacts: Fred Wohn, 515-294-3545
Del Bluhm, 515-294-3757
Saren Johnston, 515-294-3474
AMES, Iowa -- The U.S. Department of Energy's Ames Laboratory and Iowa State University (ISU) will welcome more than 70 physicists and engineers from around the world when they come to Ames to attend the annual PHENIX Collaboration Meeting June 22-27. ISU campus sites for the meeting's various sessions include Gilman Hall, the Physics Building, Ames Lab's Technical and Administrative Services Facility, and Spedding Hall.
PHENIX, a detector system as large as a medium-sized house, will make it possible to detect, identify and measure the momentum and energy of thousands of subatomic particles created when gold nuclei traveling at close to the speed of light collide inside the Relativistic Heavy Ion Collider (RHIC), an accelerator under construction at DOE's Brookhaven National Laboratory on Long Island, NY. Through these collisions, scientists hope to recreate the quark-gluon plasma (QGP). A unique form of matter, the QGP existed for less than a thousandth of a second and at temperatures greater than a thousand billion degrees Celsius an instant after the "big bang," when our universe was born.
"The main reason for the annual collaboration meeting is for physicists with common interests to form working groups, each of which will focus on a different physical process related to the PHENIX detector," explains Fred Wohn, an Ames Lab associate and an ISU professor of physics. "During the week, there will be seven working groups meeting in parallel for a few days, then coming together at the end of the week to share reports. Heavy ion physics, using colliding beams of heavy nuclei, such as gold, and spin physics, using colliding beams of polarized protons, will both be possible with the PHENIX detector."
Wohn and Del Bluhm, manager of Ames Lab's Engineering Services Group (ESG), respectively lead the team of nine ISU physicists and seven ESG staff members, whose job is to design and build the Level-1 Trigger for the PHENIX detector. The Level-1 Trigger is at the heart of the detector's decision-making process. It determines which collision events may contain interesting physics and which can be discarded. "The RHIC beams collide 9.4 million times per second, so the Level-1 Trigger is essential to maintain selectivity and control," explains Bluhm.
The Level-1 Trigger receives signals from six of the detector subsystems. After processing this data, it makes a decision to either discard the event or pass it on. "This decision-making process takes about 4.2 microseconds, so the trigger will process the signals from 40 beam crossings simultaneously," says Wohn.
The entire PHENIX Collaboration consists of over 430 physicists and engineers from 43 participating institutions in 11 countries, plus an equivalent number of support personnel. The PHENIX detector and the RHIC are both scheduled to become operational in the fall of 1999, and the first RHIC physics run will begin at that time.
Bluhm, Wohn and Marzia Rosati, also an ISU physics professor, are organizing the week-long PHENIX Collaboration Meeting at which participants will review the status of the PHENIX detector and the physics to be done with it. "The PHENIX On-line Group, of which the Level-1 Trigger is a part, will meeting during this week to focus on a plan to test how the various electronic components of the PHENIX interact with one another," says Bluhm.
"The scientists and engineers in the PHENIX Collaboration are enthusiastic about the exciting new physics they expect to see in the fast-approaching 'RHIC era'," says Wohn. "They hope to answer two outstanding questions of fundamental science: what happened during the first few moments of the early universe, and how does the proton get its spin."
Ames Laboratory is operated for the DOE by ISU. The Lab conducts research into various areas of national concern, including energy resources, high-speed computing design, environmental cleanup and restoration, and the synthesis and study of new materials.
Last revision: 6/17/98 sd