This summer, Fermilab’s NOvA neutrino experiment confirmed the oscillation of muon neutrinos into electron neutrinos. Pictured here is the NOvA Far Detector in Ash River, Minnesota. Photo: Reidar Hahn
The Nobel Prize-winning discovery of neutrino oscillations by the Super-Kamiokande and SNO experiments put a big crack in the highly successful Standard Model of elementary particles and their forces. The historic discovery showed that the Standard Model cannot be the complete theory of the fundamental constituents of the universe, and many questions remain: Why are neutrinos so much lighter than all other matter particles? How do neutrinos get their mass? What is the neutrino mass ordering? How are neutrinos related to dark matter? Do neutrinos and antineutrinos behave differently? And, ultimately, scientists want to know: Are neutrinos the reason matter exists?
Experiments at Fermilab and other laboratories are investigating neutrino oscillations in detail to discover the physics beyond the Standard Model. Using neutrinos created by particle accelerators and nuclear reactors, scientists make measurements that go beyond the original neutrino oscillation results based on cosmic and solar neutrinos.
At Fermilab, the Main Injector Neutrino Oscillation Search began taking data in 2005. A year later, the first MINOS result corroborated earlier observations of muon neutrino disappearance, made by the Japanese Super-Kamiokande and K2K experiments. In the following years, MINOS made detailed measurements of neutrino oscillation parameters.
The NOvA experiment at Fermilab, which began taking data in 2014, released its first neutrino oscillation results earlier this year. While researchers know that neutrinos come in three types, they don’t know which is the heaviest and which is the lightest. Figuring out this ordering — one of the goals of the NOvA experiment — would be a great litmus test for theories about how the neutrino gets its mass. While the famed Higgs boson helps explain how some particles obtain their masses, scientists don’t know yet how it is connected to neutrinos, if at all. The measurement of the neutrino mass hierarchy is also crucial information for neutrino experiments trying to see if the neutrino is its own antiparticle.
Fermilab neutrino experiment MINOS first witnessed neutrino oscillations in 2006. This is the MINOS Far Detector, located in Soudan, Minnesota. Photo: Reidar Hahn
The planned Deep Underground Neutrino Experiment aims to determine whether neutrinos could be the reason that matter exists. It will study neutrinos as they pass 800 miles through the earth and measure whether neutrinos adn antineutrinos behave differently, and help unravel the mystery of why the early universe created more matter than antimatter. The DUNE detectors also will look for neutrinos from a core-collapse supernova. The data would allow scientists to peer inside a newly formed neutron star and potentially witness the birth of a black hole. About 800 scientists from 26 countries are collaborating on DUNE.
The long-baseline neutrino experiments at Fermilab are complemented by a suite of other neutrino experiments dedicated to the search for additional types of neutrinos and studying their interactions with matter.
Fermilab’s research on neutrinos is as old as the lab itself. Its first experiment, E1A, was designed to study the weak interaction using neutrinos and was one of the first experiments to see evidence of the weak neutral current. (See the CERN Courier for more details.)
While much of the progress of particle physics has come by making proton beams of higher and higher energies, the most recent progress at Fermilab has come from making neutrino beams of high intensity. Fermilab’s flagship accelerator recently set a high-energy neutrino beam world record when it reached 521 kilowatts. The laboratory is working on improving neutrino beam intensities even further for NOvA, DUNE and other neutrino experiments.
Hear about the history of the prairie on Sept. 30 and join in the annual prairie harvest on Oct. 3 and Nov. 7
It’s a time of celebration for the Fermilab community: The Robert Betz prairie, once the largest prairie restoration project on Earth, turns 40 this year.
It’s been four decades since the U.S. Department of Energy’s Fermi National Accelerator Laboratory, working with local conservation groups, dedicated 650 acres of its property to growing and maintaining a variety of natural tall grasses and plants.
Over time, the prairie has been restored to roughly 1,000 acres, maintained through the assistance of a dedicated group of local volunteers and the Fermilab grounds crew. The laboratory was recently awarded the Conservation@Work Award from the Conservation Foundation for its decades of dedication to preserving the prairie.
Over the next few weeks, you’ll have three opportunities to be part of the anniversary of the prairie at Fermilab. On Wednesday, Sept. 30, at 4 p.m., Ryan Campbell, Fermilab ecologist, will give a talk on the history of the prairie. The presentation, part of the lab’s Colloquium series, is free and open to the public.
And on Saturday, Oct. 3, and Saturday, Nov. 7, at 10 a.m., Fermilab will host its annual prairie harvest, inviting volunteers from the local community to help diversify the prairie. Fermilab has been hosting the Prairie Harvest every year since 1974, and the event typically draws more than 200 volunteers.
The main collection area covers about 100 acres, and within it, volunteers will gather seeds from about 25 different types of native plants. Some of those seeds will be used to replenish other acres of the Fermilab prairies, filling in gaps where some species are more dominant than others.
“Our objective is to collect seeds from dozens of species,” Campbell said. “Our thousand acres of restored grassland is not all of the same quality. We want to spread diversity throughout the whole site.”
The event will last from 10 a.m. to 2 p.m., with lunch provided. Volunteers will be trained on different types of plants and how to harvest seeds. If you have them, bring gloves, a pair of hand clippers and large, paper grocery bags.
In case of inclement weather, call the Fermilab switchboard at 630-840-3000 to check whether the Prairie Harvest has been canceled. More information on Fermilab’s prairie can be found at the Fermilab ecology website. For more information on the Prairie Harvest, call the Fermilab Roads and Grounds Department at 630-840-3303.
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. 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.
Fermilab is contributing to accelerator programs at Northern Illinois University and the University of Chicago. The aim of these programs is to improve particle beam delivery, including the performance of superconducting radio-frequency technology. Photo: Reidar Hahn
Particle accelerators shape our everyday lives. They are powerful tools in medical diagnosis and treatment. They were used to develop materials in everything from your cell phone screen to the chips in your computer. They even help us explore the fundamental particles and forces that make up the world around us. Until 2014, the National Science Foundation did not have a program funding fundamental R&D on accelerator science. This year marks the second year of this newly initiated program.
This year, the NSF is awarding grants to fund research on the development of bright beams at the University of Chicago and Northern Illinois University at a level of $680,000 and $560,000, respectively, for a three-year period. In both programs, Fermilab will play an integral role in exploring and pushing the limits of accelerator science.
The University of Chicago proposal, titled “Innovations in Bright Beam Science,” calls for the development of a program to make high-powered, stable beams with low losses. It comprises three themes: studying superconducting radio-frequency cavities; conducting a proof-of-principle experiment with circular accelerators to investigate ways to produce more stable beams; and exploring techniques to produce more intense X-rays. The first two of these are parts of a bigger R&D program at Fermilab, including the superconducting radio-frequency program and the Integrable Optics Test Accelerator.
This will be the first time the University of Chicago will assemble a group working on an accelerator program. Beyond improving accelerator technology, one of the goals of the program is to attract faculty members and students to accelerator research.
“The benefit from this is that we bring in chemistry and mathematics professors who would never otherwise be exposed to our research,” said Fermilab Accelerator Division Head Sergei Nagaitsev. “This is an opportunity for us to collaborate with colleagues who ordinarily don’t collaborate with Fermilab.”
The NIU proposal is called “Development of Ultra-cold Quantum-degenerate Relativistic Electron Beams for Research and Applications.” The NSF-funded research at NIU will address the question of whether they can produce a beam a thousand times cooler in temperature than existing beams, resulting in higher beam brightness and quality.
“Everybody’s trying to get to high energies, beam powers and intensities quickly, but nobody is working on producing high-quality, ultracold beams like these,” said Swapan Chattopadhyay, principal investigator of the NSF-funded project at NIU. “No matter what you do with a beam, you can not do any better than the intrinsic goodness of the beams. We’re working on producing beams not only of high energy and intensity, but also of very good purity and quality.”
The researchers, physicists and engineers aim to produce electron beams from specially designed nanocathodes immersed in high electric fields, packing and focusing the electrons tightly. The beams will be cold enough to serve as a source for high-quality compact X-ray lasers.
NIU will carry out the experimental work at Argonne National Laboratory and Fermilab and plans to collaborate with Cambridge University Graphene Center.
With Fermilab’s infrastructure and expertise in accelerator science and technology, the laboratory will offer a place to test and expand the ideas developed throughout the research, while the universities will have the capability and time to delve deep into a problem. The proposals emphasize student training and education and will give Fermilab access to high-caliber graduate students at the University of Chicago and NIU.
“The university brings the academic depth and focus,” Chattopadhyay said. “Fermilab brings national expertise, infrastructure and a breadth of skills and resources, and by collaborating with industry, we will also get a practical perspective.”
Although NIU and the University of Chicago are focusing their efforts on different issues, they share the goal of creating accelerators that are more powerful than the ones currently in use. The two are very complementary, Chattopadhyay said, and he hopes they can collaborate to create something that is larger than the sum of its parts.
“These are scientifically very exciting questions,” said Young-Kee Kim, lead of the University of Chicago research program. “We continue to push our technology to get better accelerators with brighter beams, but there are a lot of limits we have to overcome. That limit can be overcome only by understanding all these issues and limitations at a very fundamental level.”