After 14 years, the wait is over.
The physicists rejoicing all over the world include a team from The University of Arizona.
At 1:28 a.m. Tucson time, the first beam of protons zipped completely around the Large Hadron Collider - the largest particle accelerator ever built.
UA physicists built part of a massive instrument called ATLAS that is inside the collider.
As the proton beam sped through the 17-mile circular tunnel about 100 yards under the Franco-Swiss border, the beam passed through the ATLAS detector.
UA physicist Walter Lampl wrote in an e-mail from Switzerland, "This morning, I followed the events in the CERN Control Centre via a video link. Things progess much faster than I had expected. It took only about 2 hours to get one beam circulating."
The UA is the only university in Arizona involved with the LHC. The LHC is operated by the European Organization for Nuclear Research, known as CERN, located in Geneva, Switzerland.
When the LHC, the largest scientific instrument ever built, is fully operational, it will shoot two proton beams around the collider so the beams smash head-on. The resulting shower of subatomic particles and energy will help physicists learn more about the fundamental workings of the universe.
Lampl reported that by 6 a.m. Tucson time a second proton beam had made a complete circuit of the collider. "I am optimistic that we will see collisions quite soon."
Physicists involved with the LHC anticipate first collisions within the month.
Ken Johns, a UA professor of physics who is also a member of the UA-ATLAS team, reported getting up early in Tucson to start reading the experiment logs and met "an avalanche of email."
"I am happy and excited by the achievement of first beam in the LHC," he wrote in an e-mail. "Now the real work begins. On the accelerator side, collisions must be established. On the ATLAS experiment side, all the detectors must be precisely calibrated. Starting now, we are going to have a frantic, day-and-night battle to understand the ATLAS detector so we can get to the physics."
The normally reserved scientist signed off, "For moment, yippee!"
More than 150 feet long and 82 feet across and weighing more than 7,700 tons, the ATLAS detector is the world's largest general-purpose particle detector.
Key parts of ATLAS were built in the basement of the UA's physics building.
UA Professor of Physics John Rutherfoord led the team that built part of ATLAS called the Forward Calorimeter. He reported today that he and his colleagues will be slowly turning on that instrument and the instrument may record particles hitting the calorimeter today.
Team member Elliott Cheu, a UA professor of physics, wrote in an e-mail, "We saw the first events in the ATLAS detector and things look great!"
To celebrate the LHC's first beam, the UA physics department held the public lecture, "From the Big Bang to Dark Matter: Turning on the Large Hadron Collider," Wednesday night on the UA campus.
Cheu, also the associate dean of UA's College of Science and member of the Large Hadron Collider-ATLAS team, delivered the lecture.
Robert N. Shelton, UA president and professor of physics, made the opening remarks.
"We are extraordinarily proud that this university has scholars that could be chosen to play a part in such an international collaboration," Shelton said at the lecture. "You don't get there just because you want to be there, you get there because you are the best in the world."
In his lecture, Cheu discussed the UA's participation in building the LHC and explained how the experiments to be conducted inside the LHC will reveal secrets about our world.
"This, for us, is the work of a lifetime. At least for particle physics, it's probably the event of the decade," Cheu said. "We think that not only is it going to have an impact on the scientific world, but I believe that it's going to have an impact on the whole world in both our understanding of the universe and also the underlying forces and particles that go into it."
The UA LHC-ATLAS team includes UA physics professors John Rutherfoord, Michael Shupe and Kenneth Johns and Erich Varnes, a UA associate professor of physics.
Shupe and Rutherfoord have been working on the project for 14 years. The team also includes seven UA postdoctoral and graduate students, three engineers and two technicians. More than 20 UA undergraduate students were involved in the research and building of the UA portions of ATLAS.
Rutherfoord, Shupe and other members of the UA's ATLAS team led the design, construction and installation of the Forward Calorimeter, an instrument that measures the position and the tremendous energies of the particles given off when the proton beams collide.
Cheu, Johns and others were responsible for instrumentation for the Cathode Strip Chambers that will detect the high-energy particles called muons.
"This isn't just a science experiment that's begun. It is a moment of real institutional pride. These colleagues in the physics department here have stayed with it for many, many years," Shelton said.
All of the members of the UA-ATLAS team are in the UA's physics department. Other members of the team are doctoral students Xiaowen Lei, Caleb Parnell-Lampen and Chiara Paleari; Peter Loch, an associate research scientist; Alexandre Savine and Joel Steinberg, research engineers; Walter Lampl, an assistant research scientist; Venkatesh Kaushik, a research associate; Leif Shaver, a staff engineer, senior; Dan Tompkins, an engineer; Michael Starr, a test technician; and Robert Walker, an engineering aide.
When it is operating at full strength, the LHC will produce beams of protons seven times more energetic and about 30 times more intense than any previous machine. Two beams will shoot around the 17-mile underground particle racetrack and collide head-on, creating 600 million collisions per second.
When the protons smash together, they will break apart and elementary particles, the smallest building blocks of matter, will shoot off in all directions.
The aftermath of the collisions will simulate some of the conditions that occurred one-trillionth of a second after the Big Bang that started the universe.
One goal of the experiment will be to understand the origin of mass, Cheu said.
The collisions will occur at enormous energies and therefore create immense masses, according to Einstein's famous E=mc2 formula.
One massive particle that has been predicted but never seen before is the Higgs particle.
"If we find the Higgs, that will be fantastic - and that will be confirmation of what we expect," Cheu said. "But if we don't find it, that may be confirmation of more exotic theories."
Kenneth Johns said another goal of the LHC is figuring out the origin of dark matter.
"Twenty-five percent of the universe is composed of something we don't know or understand," he said.
The ATLAS Collaboration, like other pieces of equipment that make up the LHC, involves an international team of scientists. The international effort involved 2,500 scientists from 37 countries. The 650 participants in the US-ATLAS team come from 43 American universities and national laboratories and represent 21 states.