In September, lab employees move to Weston, Colorado bison move to Illinois, and Nigel Lockyer moves to the United States. Read on for more September historical milestones.
This is the first lab bison, in 1970.
In September 1969, the first bison arrived on the lab site. The first six animals were purchased by the lab from a herd in Colorado, and the next year a larger group arrived from a herd in Illinois. The bison were part of Director Robert R. Wilson’s vision of the lab as a physical and intellectual frontier and contributed to his goal of restoring some of the the native ecosystems of the area.
Nigel Lockyer became Fermilab’s sixth director on Sept. 3, 2013. Lockyer spent 22 years as a researcher on Fermilab’s CDF experiment and served as the co-spokesperson from 2002 to 2004. He also won the 2006 W.K.H. Panofsky Prize. When he became Fermilab’s director, he was director of Canada’s TRIUMF Laboratory.
A patient sits in the Neutron Therapy Facility treatment room.
Director Robert Wilson is sometimes known as the “father of proton therapy” for his 1946 paper “Radiological Use of Fast Protons,” which first suggested the idea of using protons for medical treatment. Wilson helped organize Fermilab’s Cancer Therapy Facility, as it was originally known, using funding from the National Cancer Institute and beam from Fermilab’s Linac. The Neutron Therapy Facility treated its first patient on Sept. 7, 1976. In 1989, Fermilab would design and build a proton accelerator for Loma Linda University Medical Center in California, the first hospital-based proton treatment center.
The Dark Energy Camera took this photo.
Fermilab is a member of the Dark Energy Survey, an international collaboration formed in 2003 that uses a camera mounted on the Blanco Telescope in Chile to study the effects of dark energy. On Sept. 12, the Dark Energy Survey’s Dark Energy Camera received first light.
This building received its name in 1980.
Shortly after Fermilab’s first director, Robert R. Wilson, retired, the lab renamed the Central Laboratory Building to Wilson Hall in his honor.
Flag raising in front of the director’s office in Weston on Sept. 24, 1968.
NAL employees started moving to the Weston site during the summer of 1968 and completed the move at the end of September.
Fermilab’s first three directors were present for the dedication. From left: John Peoples, Leon Lederman and Robert Wilson.
Fermilab’s Lederman Science Education Center was named in honor of the lab’s second director, Leon Lederman, in recognition of his work to improve science education.
Left: The Bubble Chamber is under construction. Right: This picture shows an example of bubble chamber tracks.
Bubble chambers detect particles by recording tracks of bubbles the particles leave in liquid, and Fermilab was home to the largest liquid-hydrogen bubble chamber in the world. The 15-Foot Bubble Chamber photographed its first particle trails on Sept. 29, 1973. It would record its last tracks on Feb. 1, 1988.
Helen Edwards, one of the designers of the Tevatron, helps shut it down.
After the more powerful Large Hadron Collider at CERN began operating in 2008, Fermilab retired the Tevatron.
Paintbrush
Back in 1972 or so, while I was a graduate student at Cornell University, fellow graduate student Steve Herb joined Fermilab experiment E-26. On one of his regular visits back to Cornell, Steve said that he was called into Fermilab Director Bob Wilson’s office. “What for?” I asked. Apparently Fermilab artist Angela Gonzales was not very happy about the green color that Steve had painted his toroid magnets.
Steve said that he could remove the windings that they had laboriously placed on the steel toroids, repaint and restore the windings. However, that would probably kink the windings, which would require the purchase of new copper cables. So he asked Bob whether he should do that.
Steve said that Bob replied something like, “Oh, it’s OK. But next time, before you pick up a paint brush, check with Angela first.”
These are the magnets from E-26, which were mispainted green. Photo: Fermilab
Viewpoint
In June 1978, Fermilab Director Bob Wilson’s sculpture “Broken Symmetry” was erected at the Pine Street entrance to Fermilab. I had been away on the day that it was erected, so later that evening my wife Jean and I walked in from our nearby home in Batavia to check it out.
Just as we approached “Broken Symmetry” from the west, Bob Wilson drove in from the east. He asked, “What do you think?” I said, “Pretty interesting … why did you paint it black?” Bob replied, “It’s not black, it’s orange.” Startled, I said “Say what?” Bob replied, “Come over here,” at which point I realized what he had done. I guess you just shouldn’t ask an artist “Why?”.
“Broken Symmetry” is black on one side … Photo: Reidar Hahn
… and orange on the other. Photo: Reidar Hahn
“Broken Symmetry” was under construction in 1978. Photo: Fermilab
A paint job
In 1983, as we prepared for the first beam from the Fermilab Tevatron, we refurbished and upgraded all of our facilities in the Fixed Target Experimental Areas. Although the Tevatron was to be capable of running at an energy of 800 GeV, the first few months of operations were to be limited to 400 GeV in order to finish off some experiments that were not to be upgraded to 800-GeV capability. I added a second dipole magnet to the single-dipole magnet in the Proton East primary beamline (my version of the Energy Doubler). In November 1983, a colleague was trying to tune the first Tevatron 400-GeV beam through these two dipoles in Proton East, without luck. The beam somehow got lost in those 40 feet of magnets. I walked into the control room and, using the beam loss monitors, was able to thread the beam through the two dipoles, but at 50 percent greater electrical current than expected. This indicated some sort of electrical short, which meant lower magnetic field and less bending. Since we had designed for 800-GeV operations, this extra current was within our tuning range at 400 GeV, at least for the short term.
During the next interruption of accelerator operations, that typically occur while commissioning a new machine, I accessed the Proton East beamline to see if I could determine what the problem was. Everything looked normal until I noticed that that the beam pipe on the upstream B2 dipole was a little wider (5 inches) than for the downstream B2 dipole (4 inches). “What the…!?!” One of those baby blue (NAL Blue Light) dipole magnets was really a B1 dipole, which should have been dark blue (NAL Blue Dark). The inner coils of the B1 and B2 dipoles are wired exactly opposite, so when the electricians saw the baby blue color, they had hooked up the B1 magnet as if it were a B2 magnet, thereby setting them up so that the two outer coils produced magnetic fields pointing upwards and the one inner coil produced a magnetic field pointing downward. This reduced the net field in that magnet, requiring more current to get the required beam bending. Once this was realized, it was an easy fix to reconfigure the connections for proper operation. With a Sharpie pen, I wrote on that miscolored magnet, “This is really a B1 magnet.” Yes, I should have noticed that error before beam arrived, but that level of subtlety was a little beyond normal.
The next workday, I discussed this with the engineer in charge of the beamline installations who said that earlier, in the shop, they had given a summer student a can of baby blue paint and told him to “paint those magnets,” not realizing that there was a B1 in among the B2s.
You’d be hard-pressed to tell the difference between these two types of magnets (B1 upper, B2 lower), which were both painted light blue, installed in the beam tunnel simply from the widths of their beam pipes.
Andy Hocker, left, and Mike Lamm stand beneath a cryostat lid, from which a magnetic section will be suspended. Photo: Reidar Hahn
In July 2015, a key cryogenic facility at Fermilab was shut down, leaving the laboratory’s Mu2e experiment without a space to test its superconducting magnets. Luckily, in the search for new physics at Fermilab, it’s “waste not, want not”: A new cryogenic testing facility for Mu2e now lives in a space occupied by a previous experiment, called CDF, and is even created with refurbished parts from past experiments, including CDF.
The Mu2e experiment aims to capture a hypothesized phenomenon that has never been observed: a particle called a muon converting directly into an electron. If scientists were to witness this rare event, it could signal that there are other, hidden particles in the universe yet to be discovered.
“The idea of Mu2e is rather simple: to detect this reaction,” said Michael Lamm, one of the lead scientists on the Mu2e experiment. “We’re going to measure it to a sensitivity that’s never been reached.”
The Mu2e experiment is specifically designed to achieve this unmatched sensitivity. Comprising three superconducting magnet sections, it stretches nearly the length of a lap pool — about 75 feet.
The experiment’s most distinctive feature is its S-shaped central section, called a transport solenoid, which contains 52 coils of superconducting wire that act as magnets. Manufacturers in Italy will wind each coil and place them into 14 sections, which will be assembled at Fermilab to create the solenoid’s serpentine shape.
But before the solenoid can be put together, each section of the magnet needs to be tested to make sure it works under the ultracold conditions necessary for superconductivity.
“Imagine you build the magnet, transport it into the building and put it in place. And then you turn it on and the magnets don’t work. It would be very risky,” Lamm said.
To eliminate this possibility, the 14 solenoid sections, each containing between two and five coils, will be sent to Mu2e’s new cryogenic testing facility before assembly. The magnet vendor will have already tested the magnets at room temperature to check for electrical issues such as short circuits, but at Fermilab’s cryogenic testing facility, the sections will really be put through their paces.
On the upper level, a technician works on the Mu2e cryostat. On the ground level, a separate cryostat lid is being prepared for use. Photo: Reidar Hahn
“Since these magnets are superconductors, they have to be cooled down to liquid-helium temperatures—about 5 Kelvin,” said Andy Hocker, leader of the cryogenic facility. “We’ve put together this facility to make sure they’ll be able to operate as they will in the experiment.”
To reach frigid 5 Kelvin (that’s about minus 451 degrees Fahrenheit, a few degrees warmer than outer space), the magnet sections are suspended in a cryostat, which Hocker called “a glorified thermos.” Inside the cryostat, the magnet is isolated from the warmth of the outside world, allowing the section to be slowly cooled with liquid helium, a process that takes about a week.
And then comes the real test: running an electrical current through the coils that’s 20 percent higher than the one that will be used once Mu2e is online.
“You want to make sure these magnets can go up to well beyond the current they’ll need to operate at during the experiment and still stay nice and cold to keep them from transitioning to a normal conductor,” Hocker said.
Each solenoid section will take four to six weeks to test, including the gradual cooling and an equally slow warming period. The first section will arrive this fall, beginning a nearly two-year testing process that should be complete by 2019.
Once the transport solenoid has been tested, constructed and joined with two other sections to make up the Mu2e detector, the experiment will begin a three-year run in search of physics beyond the Standard Model.
“If we see this interaction here, this would be new physics. It would really just knock your socks off,” Lamm said. “If we don’t see it, we’ll be able to rule out some of the current theories predicting new physics beyond the Standard Model. Either way, we’ll find out the truth from nature.”