The linear accelerator at the Fermilab Accelerator Science and Technology facility recently ramped up a beam of electrons to 300 MeV, surpassing the threshold needed to launch a new accelerator physics program at Fermilab. Photo: Giulio Stancari
On Nov. 15, a team at the Fermilab Accelerator Science and Technology (FAST) facility ramped up a beam of electrons to 300 million electronvolts.
It was a double milestone event. For one, the beam surpassed the threshold needed to launch a new accelerator physics program at Fermilab supported by the DOE Office of Science. The driving goal of the FAST facility is to support a new R&D accelerator that will require a minimum of 150 million electronvolts (MeV) of electron beam energy.
“It’s a great achievement and an important milestone for the project and the laboratory,” said Jerry Leibfritz, project engineer for FAST.
It was also a hard-earned success for the larger particle accelerator community. For the first time anywhere, the Fermilab group achieved a beam energy of 250 MeV from a single ILC-type cryomodule. For years, a worldwide R&D effort has been under way to develop cryomodules — accelerating structures — for the proposed International Linear Collider under development by a broad international collaboration for possible construction in Japan. The beam energy milestone was one of the goals of the international ILC R&D effort.
“Getting to a 300-MeV electron beam is a big deal for Fermilab’s accelerator R&D,” said Vladimir Shiltsev, head of the Fermilab Accelerator Physics Center. “We’re happy we could advance this R&D on two fronts.”
The delivery of the high-energy electron beam enables the start of the accelerator research program at FAST and demonstrates that the facility is up to the job of supporting the future Integrable Optics Test Accelerator, or IOTA, scheduled to come online in mid-2018.
The IOTA idea
The team behind IOTA, a 40-meter-circumference ring, is looking to break new ground in beam physics research. Once it is operable, scientists and engineers will inject beams of electrons from FAST accelerators into the ring, where they can be maintained and used to carry out R&D for new, advanced accelerator equipment and techniques.
Although technology behind accelerator-based particle physics has made huge strides over recent decades, all current accelerators use magnets with linear focusing to stabilize and guide particle beams. The technique can only advance so far, however, before fundamental physics effects, which tend to destabilize beams, limit the experimental possibilities.
To solve this problem, Fermilab began a research program to develop a number of novel accelerator techniques, and IOTA will be the pinnacle of this effort. Scientists from around the world will be able to use the next-generation accelerator to collaborate and test innovative ideas, finding ways around the physics constraints to reach the next level of accelerator beam power.
For IOTA to carry out successful research, the FAST scientists chose a minimum threshold of energy for the injected particles.
“Generally speaking, the more energy, the better the particle stability, but then you have to increase the technical complexity,” said Alexander Valishev, Fermilab scientist and head of the IOTA/FAST Department. “We chose 150 MeV as the electron energy for IOTA because it’s a good balance between energy and expense.”
The team used a specialized beamline to produce the high-energy electron beam.
“One of the biggest challenges in achieving this milestone was just getting all the complex systems and components of the accelerator to integrate and work together,” Valishev said.
The Fermilab Accelerator Science and Technology facility supports the research and development of accelerator technology for the next generation of particle accelerators. Photo: Jerry Leibfritz
World-record beam
In one sense, it was an achievement decades in the making. At the core of the electron-beam accelerator are superconducting elements whose development at Fermilab began in earnest in the late 1990s. That was the start of the development of SRF — superconducting radio-frequency technology — at Fermilab.
SRF is the technology of choice for many current and future particle accelerators, including machines under construction now in the United States and Germany, Fermilab’s PIP-II accelerator that will provide high-intensity beams for neutrino experiments, and the proposed ILC. The ILC’s technical design, completed in 2012, requires that each 12-meter-long unit of the accelerator, called a cryomodule, deliver an electron beam energy gain of 250 MeV at a particular maxiumum gradient, which is a measure of how much energy the beam gains over a given distance. It was a formidable task for SRF experts and accelerator physicists worldwide.
Now the highest-energy beam ever accelerated through the ILC-type cryomodule at design specifications has been demonstrated at Fermilab.
“In October 2014 Fermilab successfully operated the superconducting elements in this cryomodule to the nominal ILC gradient, but without accelerating an actual electron beam. The milestone achieved this month proves the expected performance definitively,” said physicist Marc Ross of SLAC National Accelerator Laboratory. “The work done over the last years has paid off, the calibrations were correct, and the cryomodule delivered as required. It is a critical milestone toward the realization of ILC.”
FAST friends
The FAST team are now engaged in joint experiments with external collaborators, such as physicists from Northern Illinois University, the University of Chicago and Los Alamos National Laboratory.
“We are very happy to have another working accelerator at Fermilab,” Valishev said. “FAST and IOTA will enable high-impact research and will be very useful for establishing more international collaboration.”
The IOTA/FAST collaboration currently has 27 partners, including CERN and the University of Oxford. The team aims to finish the ring’s construction by early 2018 and to have it up and running by the summer. Injections of protons into the IOTA ring is expected a year later.
“This is a tremendous accomplishment for all of us who have been involved in building this facility for the past decade,” Leibfritz said. “In 2006, a small group of us laid the first concrete blocks for the FAST test cave. This successful acceleration of beam really is the greatest testament to everyone who’s been involved in making it a reality.”
Fermilab is America’s premier national laboratory for particle physics and accelerator research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance LLC, a joint partnership between the University of Chicago and the Universities Research Association, Inc. Visit Fermilab’s website at www.fnal.gov and follow us on Twitter at @Fermilab.
The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.
In past Decembers, the laboratory recognized the importance of its future site, the prairie and its buildings.
A student learning about prairie ecosystems at Fermilab.
In December 1989, the prairie interpretive trail was named for Margaret Pearson, longtime Manager of the Public Information Office and an original member of the Prairie Committee.
The Feynman Computing Center was dedicated in 1988.
Feynman Computing Center, originally built as the lab’s Central Computing Facility, was dedicated on Dec. 2, 1988. It was named for Richard P. Feynman, a famous theoretical physicist.
This shows an aerial view of Weston, Illinois, in 1968.
The Atomic Energy Commission received 126 proposals recommending about 200 sites in 46 states for the planned National Accelerator Laboratory before its June 15, 1965, deadline for site proposals. It narrowed the list down to 85 and passed it to the National Academy of Sciences Site Evaluation Committee, which in turn narrowed the list down to seven in March 1966. Illinois had to withdraw its South Barrington site from the competition, leaving Sierra Nevada, California; Denver, Colorado; Ann Arbor, Michigan; Brookhaven, New York; Madison, Wisconsin; and Weston, Illinois. AEC staff visited and evaluated each site before selecting Weston on Dec. 7, 1966. The AEC issued a press release announcing the selection of the site on Dec. 16, 1966.
The Illinois Accelerator Research Center at Fermilab was dedicated in 2011.
Fermilab broke ground on IARC, the Illinois Accelerator Research Center, on Dec. 16, 2011. IARC exists to facilitate partnerships between Fermilab and private industry for the commercial and industrial application of accelerator technology to medicine, energy and the environment, industry, national security, and discovery science.
Sept. 30, 1979, about 1:45 p.m.: SNAP!! @#@#@#@!!! Gerd Hartner, in the bow of his canoe at the race starting position, dipped his paddle in the water, gave a mighty first pull and, to his astonishment, broke it in half. Hilarity ensued among the cheering onlookers. Recovering quickly from the shock, Gerd was handed a replacement paddle so he and teammate David MacFarlane in the stern could start again.
This was one of the more bizarre happenings at the once-upon-a-time annual Fermilab Canoe Race around the cooling ponds of the 4-mile Main Ring particle accelerator. The race was one of the most exciting extracurricular competitions in the history of physics labs and was held on a weekend in early autumn for a few years starting in 1974. The event was founded and organized by Larry Allen, an operations specialist, with help from other employees and the Amateur Radio Club (egad, the dark ages before cell phones) for communications around the ring to monitor mishaps. The race was a time trial, with each of about a dozen canoes setting off at three minute intervals. Crowds (not large!) of spectators showed up, pizza and beer were provided afterwards, and trophies were presented to the winners.
It was a grueling experience. Paddling flat out for about an hour is hard enough, but the course is interrupted by 17 exhausting portages up and around the dikes through long prairie grass and much soft mud. Competitors included university and lab physicists, graduate students, engineers and other staff members, both men and women. Some had more enthusiasm than expertise — in one race I passed a team going the wrong way desperately trying to turn their canoe back to the right direction. Often people got soaked and muddied along the way and plunged into the water after the finish line to clean up and cool off.
The 1976 record was finally broken in 1980 by the powerful team of Steve Conlan and David Carlson in a racing canoe with professional paddles. They clocked “an astonishing time of 41:17.” As far as I can tell from the Fermilab archives, this was the last time the race was held. That year George paddled with B.J. Bjorken and came in sixth.
George is a legendary figure in North American wilderness canoeing circles, having paddled all of the great rivers, and most of the rest, in northern Canada over his lifetime, but that is another story (if interested, Google “George Luste canoe”). Sadly, he died of brain cancer in 2015.
The only year I beat George was in 1979 (he could not participate the other year I won). He used a racing canoe, which gave him a bit of an advantage over the rest of us in aluminum clunkers, but he handicapped himself by inviting the new director, Leon Lederman, to be his bowman. Leon got a shoe stuck in the mud on one of the portages and spent valuable time retrieving it, worried he and George might be disqualified if he came to to the finish line only half-shoed. According to FermiNews at the time, he claimed the difference between his time and mine was “statistically insignificant.” I suppose we would have to repeat the race many times over to prove him wrong!
On that note I encourage Fermilab to think about restarting this canoe racing tradition, since the Main Ring cooling pond course is unique in the world. Perhaps a separate kayak race could be included or even a paddleboard race (how about a kite-surfing race on a windy day? — that would be interesting, participants flying over portages, etc…). The canoe races were great fun and helped relieve some of the stress of carrying out the great physics mission of the laboratory.
John Martin, a former Fermilab user who collaborated on E25, E531, E516 and E691, is a professor emeritus at the University of Toronto.
For more on the Fermilab Canoe Races, see older issues of FermiNews: Oct. 10, 1974, p. 3; Oct. 2, 1975, pp. 1-2; Oct. 8, 1976, pp. 1-2; Sept. 28, 1978, p. 4; Oct. 11, 1979, p. 3; Sept. 25, 1980, p. 3.