On Jan. 23, students at J.B. Nelson Elementary gathered in the school’s library for their first ever reverse science fair. Rather than being graded on their own projects and experiments, first- through fifth-grade students had the chance to judge Fermilab physicists on the quality and “coolness” of their displays and demonstrations.
“I was inspired to have a partnership with Fermilab when I visited with my son for a robotics competition,” said J.B. Nelson Principal Nicole Prentiss. While at the event, she ran into Peter Shanahan, co-spokesperson for Fermilab’s NOvA experiment and a senior scientist at Fermilab, who offered to give them a crash course in how neutrinos are detected.
“He proceeded to blow my mind,” said Prentiss, who immediately began looking for ways to bring the science being done at Fermilab to her school.
Fermilab scientist Peter Shanahan demonstrates how liquid-based neutrino detectors work by dropping weights in water at J.B. Nelson Elementary’s first reverse science fair. Photo: Jerald Pinson
Prentiss mentioned her idea for a collaboration at a Parent Teacher Organization meeting, which Fermilab engineering physicist Aria Soha happened to attend. Soha offered to connect Prentiss to the head of the lab’s Office of Education and Public Outreach, Rebecca Thompson, who proposed the idea of a reverse science fair. After rounding up a few additional volunteer physicists, the group hammered out the details.
The result: three interactive science demonstrations arranged in corners around the library staffed by Fermilab scientists, all of whom had a child enrolled at the school (setting the stage for a grade-school-level conflict of interest when it came time for students to pick their favorites).
Throughout the day, students arrived in their respective classes. After receiving a few quick instructions on how to judge the projects, they split up into three groups to view the demonstrations.
Shanahan and Soha gave a presentation on the types of particles that make up matter, comparing them to Legos. They focused on particles called neutrinos and why their masses are so difficult to measure. Shanahan demonstrated how objects of differing masses are affected by traveling through different media. Simultaneously dropping different toys representing neutrinos onto the table, he asked which hit first, to a chorus of conflicting answers.
Fermilab engineering physicist Aria Soha explains what types of particles make up matter and how we detect them. Photo: Jerald Pinson
“What that means is, we really can’t tell by dropping them in the air,” Shanahan said. “There’s just not enough resistance.”
When he next dropped them into a clear container of water, the students could easily tell which of the toys had the greatest mass. Similarly, he explained, it’s a lot easier to tell which neutrino is heavier if you send them through the earth instead of through air. Soha then showed the group how neutrinos are detected by activating special fibers she had on hand with an ultraviolet light.
At a second showcase, physicist Brendan Casey had the difficult task of demonstrating the concept of muon precession. But Casey – who has four kids, two of whom are currently enrolled at J.B. Nelson – knew exactly how to grab their attention.
Two videos played simultaneously on a set of computer screens. One was a scene from the movie “Ant Man,” in which the main character shrinks to a size smaller than quarks. The other displayed a simulation, developed at the University of Adelaide, of the quantum behavior of quarks. Casey asked the group which was more likely an accurate depiction of reality. Everyone agreed that the simulation was the better choice, but Casey underscored the need for conducting experiments to support their assumptions.
Then it was on to the precession lesson. “Precession” refers to a type of rotational motion. To understand how muons — a kind of subatomic particle — precess in magnetic fields, the students used Beyblades (a brand of spinning top) in three shallow plastic tubs, two of which were filled with different materials that would affect the tops’ spins. Casey, who works on the Muon g-2 experiment at Fermilab, also stressed the importance of replication. Putting that principle into practice meant almost everyone got a turn playing with the tops.
J.B. Nelson students spin Beyblades to simulate the precession of muon particles in a magnetic field. Photo: Jerald Pinson
The last project was run by Fermilab scientist Aron Soha (husband of Aria Soha, giving their child a particularly difficult choice to make that day), Fermilab engineering physicist John Kuharik and University of Illinois at Chicago scientist Marguerite Tonjes. To teach students how physicists make inferences about the internal structure of particles, they brought along a table-sized particle accelerator that smashed two pinballs into a target (in this case, fortune cookies).
After describing how accelerators work and what they’re used for, Kuharik fired up the machine and obliterated a fortune cookie, using the aphorism inside as a handy learning tool. (With a bit of subterfuge, Kuharik read from a fortune retrieved earlier that day rather than the one from the cookie they’d just smashed.)
At J.B. Nelson Elementary School’s first reverse science fair, students got to see a miniature particle accelerator that uses pin balls to smash a target. Photo: Jerald Pinson
“’You have the ability to sense and to know higher truth,’” Kuharik read. “It’s a perfect fortune for us, because that’s exactly what we’re trying to do. We’re trying to find the truth of how the world is made up, to get the best understanding of what the universe really is.”
Before the group left, Tonjes took a moment to encourage any students who might have an interest in science.
“I see people from Fermilab that look like everyone here, and there are people from all over the world,” Tonjes said. “You can be a physicist too.”
The Student Advisory Board delegates from J.B. Nelson Elementary School announce the award winners for the 2020 reverse science fair at a presentation in the Fermilab Art Gallery. Photo: Marguerite Tonjes
Then, as in a regular science fair, came the judging. Having seen the three experiment presentations, the students cast votes for their favorite. Students also filled out surveys both before and after the fair to gauge how much they’d learned about physics from each experiment. The physicist team who did the best at explaining their science would be given awards.
The following afternoon, a delegation elected from the student body traveled to Fermilab to present the awards. The kids’ choice award went to Casey of Beyblade notoriety. The award for best science communication went to Kuharik, Aron Soha and Tonjes.
“We’re hoping that this is just the beginning of a partnership,” Thompson said. “And we’re hoping that we can continue this relationship with J.B. Nelson and potentially do this same sort of program somewhere else.”
Visit the Fermilab Education and Public Outreach website to see more of the lab’s education offerings.
Fermilab is a DOE national laboratory supported by the Office of Science.
Fermilab has lost one of its giants. Award-winning engineer and physicist Alvin Tollestrup, who played an instrumental role in developing the Tevatron as the world’s leading high-energy physics accelerator at Fermi National Accelerator Laboratory and founding member of the Collider Detector at Fermilab collaboration, died on Feb. 9 of cancer. He was 95.
Tollestrup led the pioneering work of designing and testing 1,000 superconducting magnets used in the Tevatron, which operated from 1983 until 2011 and for 25 years was the world’s most powerful particle collider. This was the first large-scale application of superconductivity worldwide.
The Tevatron led to the discovery of two fundamental particles — the top quark and the tau neutrino. The top quark, discovered in 1995, was the last undiscovered particle of the six-member quark family that explains the composition of protons, neutrons and other particles. Scientists worldwide had sought the top quark since the discovery of the bottom quark at Fermilab in 1977. The discovery of the tau neutrino with the Tevatron accelerator followed in 2000.
“Alvin’s impact on the laboratory and on high-energy physics was just exceptional, and the development of technology with regard to the superconducting magnets had a tremendous impact on accelerators,” said Fermilab senior scientist emeritus Herman White. “All who knew him, socially and professionally, found him to be engaging, thoughtful and someone with a long, important history of working in the research community and here at Fermilab.”
Tollestrup was born March 22, 1924, in Los Angeles. He received his bachelor’s degree in engineering from the University of Utah in 1944. After service in the U.S. Navy, he entered graduate school at the California Institute of Technology, where he earned his Ph.D. in physics in 1950. His doctoral adviser was William A. Fowler, who shared the 1983 Nobel Prize in physics. Tollestrup then took a position at Caltech to build the electron synchrotron, a type of particle accelerator. At the time it was the highest-energy synchrotron in the world, starting at 500 million electronvolts, or MeV, finally reaching 1,300 MeV.
He joined the Caltech faculty as an assistant professor of physics in 1953. While on sabbatical at CERN, the European particle physics laboratory, from 1957-58, he helped plan and execute the first experiments on the lab’s 600-MeV cyclotron particle accelerator. The work led to the first observations of the electron decay mode of the pion (a subatomic particle consisting of up and down quarks and antiquarks). He became an associate professor at Caltech in 1958 and a full professor in 1962.
Tollestrup arrived at Fermilab in July 1975 on another sabbatical, intending to stay only six months. He ended up stretching the sabbatical to two years, during which time he worked on superconducting accelerator technology.
He joined the Fermilab staff following his sabbatical and in 1978 became head of the newly created Collider Detector Facility. He later became a founding member of the CDF collaboration, serving as its co-spokesperson from its inception in 1983 until 1992. He was instrumental in organizing the CDF collaboration, which initially consisted of 13 institutions and 87 physicists from the United States, Italy and Japan. His recruiting strategy included producing an Uncle Alvin “I Want You” poster (see page 5).
“Alvin was very accepting of collaborating with my Italian group, who had superior experience on experiments at a particle collider and comprised researchers of great quality,” said University of Pisa Professor Emeritus and former CDF co-spokesperson Giorgio Bellettini. “His scientific wisdom was rewarded by the Italians. He was treated with great respect and consideration at all times. His leadership paved the way for the success of CDF and of the Italians at Fermilab.”
The respect for Tollestrup was shared among many.
“Alvin was a collaborator of mine since the mid 1970s. As a founder and leader of CDF, he made important personal contributions, gave wise advice and strongly supported the young physicists in the collaboration,” said University of Chicago scientist Mel Shochet, who was CDF co-spokesperson from 1988-94. “He was also a good friend with a great sense of humor and a dash of good-natured teasing. I will miss him.”
During the 1990s Tollestrup also became a founding member of the Neutrino Factory and Muon Collider collaboration, which today is known as the Muon Accelerator Program. MAP is devoted to developing and testing the demanding technologies and innovative concepts needed to discover and explore exciting new regions of fundamental physics.
In 2009, along with Florida State University’s David Larbalestier, Tollestrup successfully launched and led the Very High Field Superconducting Magnet Collaboration. Its purpose was to study the applications of high-temperature superconductors to accelerator superconducting magnets.
After only two years and $4 million in funding, the collaboration significantly increased the current density of a bismuth-based superconducting material that would be needed for the next-generation of accelerators and new cutting-edge technologies for applications in industry and medicine.
His colleagues remember him as an active, engaged member of the Fermilab community.
“His insightful questions in the lab’s Joint Experimental-Theoretical Physics Seminar, aka the Wine & Cheese, will always be missed, as well as his friendly, always encouraging personality,” said Fermilab scientist Stephen Parke.
Tollestrup received many honors during his career, including the National Medal of Technology — the nation’s highest honor for technological achievement — and election to the National Academy of Sciences.
The 1989 National Medal of Technology recipients, from left: Richard A. Lundy, J. Ritchie Orr, Helen T. Edwards, Alvin V. Tollestrup. Photo: Janine Tollestrup
Tollestrup received the Robert R. Wilson Prize of the American Physical Society for Achievement in the Physics of Particle Accelerators in recognition of his contributions to the development of the Tevatron’s superconducting magnets. Other honors include Caltech’s Distinguished Alumni Award and the Superconductivity Award from the Institute of Electrical and Electronics Engineers for significant and sustained contributions to applied superconductivity.
“Alvin was, in my humble opinion, one of the giants at Fermilab on whose shoulders we all stand today,” said Fermilab scientist Elliott McCrory. “He was described to me as a ‘6-sigma physicist’ – which is our way of saying he was one in a million.”
Well-known for nurturing students and young scientists, he also is the namesake of the Tollestrup Award for Postdoctoral Research, which the Universities Research Association Inc. has presented annually since 2003. The award recognizes outstanding work conducted by a postdoctoral researcher at Fermilab or in collaboration with Fermilab scientists.
“While the research community is well aware of Alvin’s scientific contributions, I think one of the greatest legacies he leaves is his devotion to nurturing young people in the field,” said Brookhaven National Laboratory scientist Mark Palmer, who worked with Tollestrup in the Muon Accelerator Program. “Numerous young researchers were beneficiaries of his patience and incisive approach to problem-solving as he mentored them.”
Tollestrup and his wife Janine were collectors of the art of the late Martyl Langsdorf, whose work combines art and science. Many of her works were acrylic paintings of the American landscape, but she also designed the iconic Doomsday Clock image in 1947 for “The Bulletin of the Atomic Scientists.” The clock’s time symbolizes how close the world is to global disaster. Works from the Tollestrup collection, along with others from the collection of former Fermilab Director Leon Lederman and his wife Ellen, were displayed at the Fermilab Art Gallery in 2012.
“His impact encompassed the full spectrum of what a scientist can do in this field: to be able to have an impact on people who are beginning their careers, people who are in the technology part of particle physics, people who are doing work in the analysis of the scientific effort that’s come out of it, as he did on the CDF experiment, as well as the impact on preparing the next generation of scientists that will come after him,” White said. “He certainly did that tremendously well.”
Interment will be private, and memorial plans are pending. In lieu of flowers, donations in Tollestrup’s name to Fermilab Friends for Science Education or the American Cancer Society are appreciated.
Read an interview with Tollestrup in the California Institute of Technology Archives.
Read Tollestrup’s obituary.
After two years of work and contributions from hundreds of people, scientists now hold in hand the blueprint for perhaps the most ambitious neutrino experiment in the world.
Collaborators on the international Deep Underground Neutrino Experiment, hosted by the Department of Energy’s Fermilab, have published today its Technical Design Report. The document lays out everything needed to build the gigantic far detector, the largest of its kind ever built.
“It’s like the ultimate user manual,” said Fermilab scientist Sam Zeller, who served as the co-editor of the document together with Tim Bolton of Kansas State University. “Another team could come in and, based on that document, build the experiment — or at least have a start at it.”
More than 1,000 scientists from over 30 countries are working on DUNE, which is designed to explore mysteries surrounding fundamental particles called neutrinos. These tricky particles could have played a major role in how the universe evolved to be full of matter today. To examine their interactions with matter in greater detail than any other experiment, DUNE will use the world’s most powerful neutrino beam to send neutrinos 800 miles (1,300 kilometers) from Fermilab in Illinois to the Sanford Underground Research Facility in South Dakota — the longest distance of any experiment with man-made neutrinos. Precision measurements with particle detectors at Fermilab and approximately one mile (1.5 kilometers) underground at Sanford Lab aim to reveal potential differences in the behavior of neutrinos and their antimatter counterparts, antineutrinos. Understanding exactly how the particles change on their long journey through earth will give physicists clues about the history of our universe.
The DUNE Technical Design Report is the ultimate blueprint for building the experiment, providing all the details for constructing the giant detector modules. Shown here are the wire detection planes inside one of the modules. Image: DUNE collaboration
DUNE scientists will also be able to watch for neutrinos stemming from a supernova, which may go on to form a neutron star or black hole. Another goal of DUNE is to look for signals from a rare subatomic process known as proton decay. Shielded from cosmic radiation by a mile of rock, DUNE’s precise measurements of particle tracks will allow scientists to investigate whether protons live forever or eventually fall apart, bringing us closer to fully understanding the fundamental forces of nature.
Neutrinos (as well as antineutrinos) are notoriously tricky to study, passing through most matter without leaving a trace. To catch as many of them as possible, scientists use intense neutrino beams and build enormous detectors. The four massive DUNE far detector modules will be assembled like ships in a bottle, deep below the South Dakota soil. Each module will be longer than an Olympic-size swimming pool and four stories tall. Together, they will hold 70,000 tons of liquid argon, a crystal clear material that is ideal for the detailed measurement of neutrino interactions.
Completing the Technical Design Report required running enormous amounts of simulations, vetting the data recording and analysis process and ultimately making decisions about how to build the project.
“We’ve reached a big technical and scientific goal,” said DUNE co-spokesperson Stefan Söldner-Rembold, professor at the University of Manchester in the UK. “This means that the planning stage is done and we’re moving fully into the construction phase of the experiment.”
Preparations for the construction are already in full swing. Digging out a cavern to hold the massive far detectors requires moving around 800,000 tons of rock, and pre-excavation activities at Sanford Lab began with a mile-deep underground groundbreaking in 2017. Fermilab also broke ground in Illinois on both the near site preparation work and the construction of a new particle accelerator (the PIP-II accelerator project) in 2019. Scientists also built two house-sized prototype detectors, named ProtoDUNE, at CERN to test all systems before finalizing this TDR. With the final report in hand, international partners can start building the components for the experiment itself.
“This is what the collaboration has been working toward for so long,” said Ana Amelia Machado, a researcher working on the ARAPUCA light detection system for DUNE at the University of Campinas in Brazil. “There have been so many innovative ideas — we’re excited to take what we’ve learned from prototyping and start building this experiment.”
The DUNE Technical Design Report is broken into different volumes, and the DUNE collaboration has released the first four of five volumes. They cover the physics, the technical coordination and the two argon technologies chosen for the giant far detector modules: the single- and dual-phase.
The report is so meaty, it must be broken up into different volumes. The collaboration has released the first four of five volumes, combined coming in at around a whopping 570,000 words. That’s a “War and Peace” worth of scientific information.
There is a volume each dedicated to an introduction, the physics, the technical coordination, and one for each of the two argon technologies chosen for the giant far detector modules: the single- and dual-phase. The single-phase volume reflects the information learned in one ProtoDUNE testbed and lays out the design for how DUNE’s first far detector module will be constructed. The upcoming fifth volume will cover the dual-phase technology, which uses both liquid and gaseous argon. It will be finalized based on input from the operation of the dual-phase ProtoDUNE detector at CERN. DUNE collaborators are also preparing a conceptual design report for the near detector and a TDR for the software and computing designs.
“Everything that we’ve built so far has been practice for scaling up to DUNE,” said collaborator Albert de Roeck, leader of the CERN experimental neutrino group. “We’ve tested the technologies, figured out how to coordinate people from hundreds of institutions and started setting up the assembly lines to make the things we need. It’s going to be a carefully organized dance, and we’re ready to go.”
The four volumes of the DUNE Far Detector Technical Design Report published today are available online: Volume One (Introduction), Volume Two (Physics), Volume Three (Technical Coordination), Volume Four (Single-phase technology).
The DUNE collaboration comprises more than 180 institutions from 30-plus countries. To learn more about the Deep Underground Neutrino Experiment, the Long-Baseline Neutrino Facility that will house the experiment, and the PIP-II particle accelerator project at Fermilab that will power the neutrino beam for the experiment, visit www.fnal.gov/dune.
This work is supported by the U.S. Department of Energy Office of Science.