UK Consortium Collaborates with Fermilab for Quantum Experiment

Using nonstick cookware to fry your bacon and eggs can make your life easier at that moment, but scientists believe there may be long-term consequences because the chemicals used to make it nonstick are so difficult to destroy. Perfluoroalkyl and polyfluoroalkyl substances — commonly known as PFAS and often called forever chemicals — are everywhere. PFAS, a suite of thousands of chemicals that have been around at least since the 1950s, are used for a wide variety of things, from the stain protectant on some of your clothing and linens to the food wrappers on your burgers.

The problem is that natural processes are ineffective at breaking PFAS down, so they accumulate in the environment and body, much like Styrofoam does in a landfill. Experts in science and industry are seeking ways to prevent PFAS contamination from occurring in the future, but they also aim to reduce what already exists in the world today.

It turns out that high-energy electron beams are excellent candidates for destroying PFAS in the environment. Researchers at the U.S. Department of Energy’s Fermi National Accelerator Laboratory, in collaboration with 3M, have successfully demonstrated that an electron beam can destroy the two most common types of PFAS in water — PFOA and PFOS.

“The electron beam is a promising technology to break down PFAS in large volumes of water that contain high concentrations of PFAS,” said Fermilab principal investigator Charlie Cooper.

The Fermilab team, which includes scientist Slavica Grdanovska, engineering physicist Yichen Ji and Cooper, used an electron beam accelerator at the laboratory for their testing. Used for proof-of-concept testing, the Accelerator Application Development and Demonstration accelerator, or A2D2, at the Illinois Accelerator Research Center on Fermilab’s campus is also available to industry, universities and other federal laboratories as a research tool.

“The fact that we were working with 3M, a world expert in PFAS, was really the first time that you had the experts on ionizing radiation, electron beam accelerators and PFAS working on the same project,” said Cooper.

Electron beams to the rescue

Conventional water treatment methods, such as reverse osmosis, granular activated carbon or ion exchange resin, do not destroy PFAS; they simply concentrate PFAS in a form which subsequently requires treatment or disposal. In some cases, conventional water treatment techniques can even make the environmental contamination worse.

In contrast, the electron beam actively destroys the forever chemicals and does so quickly, enabling a larger volume of water to be treated in the same amount of time as some other methods. PFAS molecules are difficult to break down because they contain a carbon-fluorine bond, which is very strong and the reason PFAS are commonly used in the chemical manufacturing industry. But the strength of that C-F bond is also the reason they don’t break down in nature. The electron beam, however, is very effective at breaking that C-F bond.

Electron beams could be used in pump-and-treat methods, a common groundwater treatment approach, or in a manufacturing facility, directly treating waste streams before they leave the facility.

Demonstrating its effectiveness

The Fermilab team used PFAS-contaminated water samples provided by 3M that were sealed in gastight containers the size of a whiteboard marker. Each of the containers was made of borosilicate glass, which wouldn’t be significantly affected by exposure to electron beams, and an aluminum seal was crimped onto the glass with a piece of PFAS-free rubber between the aluminum and the glass. Great care was taken to ensure there were no PFAS in any of the materials used to house the samples. Fermilab irradiated these samples with the electron beam and shipped them back to 3M.

3M sampled both the headspace — the air at the top of the container — and the liquid to verify that the PFAS of concern had been destroyed without releasing hazardous products to the air.

PFAS are prevalent in many industries, and so is the human reliance on essential products that contain PFAS, such as computers and lithium-ion batteries. One of the most problematic PFAS-containing products in terms of environmental contamination has historically been aqueous film forming foam, or AFFF, which was used for firefighting at airports and in the military; it’s made of PFOA and PFOS. When you spray AFFF onto a liquid, it moves to the surface and extinguishes the fire by preventing oxygen from getting to it. But, when used it can seep into soil and groundwater. AFFF has been used in the United States and worldwide for decades, largely by the military and aviation industry.  Recently, both government and industry started examining PFAS-free substitutes. Alternatives, however, do not exist in many applications and are hard to find or perform less effectively.

Although electron beams are very effective at breaking down entire suites of PFAS compounds, not every compound has been tested so far. The researchers found that all of the PFAS compounds the U.S. Environmental Protection Agency is currently considering regulating in drinking water were effectively destroyed by electron beam technology. But there may be types of PFAS an electron beam cannot destroy.

Research continues on several fronts to find alternatives to PFAS. At the same time, leaders in science and industry will continue to search for and enhance methods to eradicate these forever chemicals in the environment. Fermilab and its electron-beam technology stand at the forefront of this research.

This work is supported by the Office of Energy Efficiency and Renewable Energy of the U.S. Department of Energy Office of Science and 3M.

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The 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.

Since the 1960s, scientists have discovered more than a dozen fundamental particles. They all have fit perfectly into the theoretical framework known as the Standard Model, the best description physicists have of the subatomic world. The Higgs boson, which was co-discovered by the CMS and ATLAS experiments at the Large Hadron Collider at CERN in 2012, was the last fundamental particle predicted by the Standard Model. Despite this major discovery, scientists still have many questions about the fundamental building blocks of the universe. Researchers know that the Standard Model is incomplete and cannot explain many physical phenomena—dark matter being a notable example.

Scientists around the world are pushing the Standard Model’s limits and are searching for new particles that can help explain outstanding questions about the inner workings of the universe.

“We’re in the business of finding new particles,” said Cristian Peña, the convener of the CMS exotic particles group and scientist at the U.S. Department of Energy’s Fermi National Accelerator Laboratory. “That’s what we’re here for.”

Peña and other scientists at Fermilab recently collaborated with their international colleagues on CMS to create a new tool that is allowing them to scout for particles that can travel around one to ten meters before decaying into more stable byproducts. Now scientists are analyzing the new dataset produced by this tool. According to Peña, they will either find new physics, or set the most stringent limits in the search for long-lived particles: a class of theoretical particles that can travel deep into the detector before creating visible signals.

“Our data set is no longer doubling every six months like it did at the very beginning of the program,” says Sergo Jindariani, a senior scientist at Fermilab. “The places where we could still make quick discoveries is where we haven’t looked before, and long-lived particles are an example of that.”

When scientists built the experiments for the LHC, they assumed that new particles would behave like those they had discovered in the past and decay very quickly. For example, the top quark, which was discovered at Fermilab in 1995, has a lifetime of roughly 5×10⁻²⁵ seconds. This is so short that top quarks decay before they can move the length of a hydrogen atom. But now more and more scientists are questioning this assumption.

“We’ve looked everywhere and come up empty so far,” said Peña. “We know we can do better by using the lifetime of the particles.”

Scientists already know that particles have a wide range of lifetimes. For instance, bottom quarks can travel a few millimeters before they decay, and muons can travel a few hundred meters. Today, scientists are asking, what if there are new particles that fall somewhere in-between?

Even if these long-lived particles are extremely rare, CMS will still have a good shot of seeing them if they are being produced by the LHC.

“The CMS muon system has a lot of material, so if long-lived particles are decaying inside our detector, we should see a particle shower in the muon chambers,” said Peña. “The signature is very powerful.”

But the question was whether scientists can find these unexpected particle showers hiding in their data. The LHC produces about a billion proton-proton collisions every second. Because more than 99.99% of the collisions generate particles and physical phenomena that are uninteresting, scientists use data-sorting devices called triggers. Triggers pick the top 0.01% of events to be processed and stored within the Worldwide LHC Computing Grid and discard the rest.

“CMS is an extremely successful detector,” said Jindariani. “It really does the physics it was designed to do. But long-lived particles were not something people had in mind when they were designing the CMS trigger system.”

The team realized that if they wanted to improve their chances of finding long-lived particles with the CMS experiment, they would need to update the CMS trigger to look for the striking and peculiar signature these particles are expected to leave behind in the detector.

“With a dedicated trigger, we saw that we could gain an order of magnitude in the sensitivity of these searches,” Jindariani said.

But updating the trigger is always a complicated endeavor. It required help and expertise from researchers and engineers throughout the CMS collaboration. Jindariani pointed out that the trigger system relies on numerous data streams from different parts in the detector. These data streams operate like roads in a city and allow the data to flow from the outer most parts of the detector into the “downtown” processing center, where the data is compiled and quickly evaluated by algorithms. Adding a new data stream is like adding a bike lane into an already bustling metropolitan area.

“It would need to co-exist with other triggers,” Jindariani said. “That’s a delicate play; we don’t want to damage what’s already in place.”

After extensive analysis of the CMS trigger and discussions with the collaboration, the team realized it was possible, thanks to a few unused bits left over from the original design. But then came the challenge of actually implementing their new trigger in the data processing of the experiment.

“Once everybody was onboard with the conceptual implementation, we needed to go into the firmware and software,” Jindariani said.

Firmware provides basic machine instructions that allow the hardware—in this case, Field Programmable Gate Arrays—to function according to the programmed algorithm. FPGAs can be very fast but are often not very dynamic.

“FPGAs have a limited amount of processing power, and the CMS trigger algorithms are pretty resource-hungry,” Jindariani said. “We needed to be clever in order to not overwhelm the FPGAs’ capabilities.”

Since the LHC makes protons collide every 25 nanoseconds, their new trigger also had to be fast.

“We’re locked into time slices,” Jindariani said. “The algorithm needs to be executed within a few hundred nanoseconds. If it takes longer, it’s not good enough. This work was only possible through a strong team of scientists and engineers working together.”

Even after the challenges of resource management and timing were solved, the team still had to address a few unexpected hiccups. During the testing phase, they saw that the trigger was activated during every collision. After further analysis, they found this was because the transmitter on one of the muon systems was malfunctioning.

“This was a problem that had existed before, but the other triggers didn’t see it because they weren’t looking for it,” Jindariani says.

Once all the glitches were ironed out, the trigger evaluated all the LHC collisions happening within the CMS detector between 2022 and 2023 — around 10¹⁶, or 10 million billion — and collected a dataset with around 10⁸ events. Scientists are currently analyzing this new data set and hope to have their first results this summer.

“This trigger is one of the big innovations within CMS,” Peña says. “We’ll either find new particles, or — if nature doesn’t want it that way — we will set more stringent limits on long-lived particles.”

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The 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.

Four institutions from the United Kingdom formalized their participation in the Matter-wave Atomic Gradiometer Interferometric Sensor experiment known as MAGIS-100, under construction at U.S. Department of Energy’s Fermi National Accelerator Laboratory. University of Liverpool, Imperial College London, University of Cambridge and University of Oxford signed a cooperative research and development agreement with Fermilab in November.

MAGIS-100 is an innovative, 100-meter-long interferometer experiment. Scientists aim to use cold-atom interferometry to demonstrate quantum superposition of atoms over a distance of a few meters and duration of several seconds. The measurement also will allow scientists to search for signs of ultralight dark matter interacting with ordinary matter. The research will lay the foundation for future gravitational wave detectors. It pioneers technology that could lead to interferometry experiments with baselines of more than 1 kilometer, and thus, greater sensitivity.

“It is exciting to see us expand our long and celebrated partnerships with UK institutions to new scientific domains, with the highly innovative MAGIS-100 experiment,” said Fermilab Director Lia Merminga. “Our UK partners participate in the design, construction and delivery of the detection system for the interferometer, and will also participate in the commissioning and data analysis of the experiment.”

Mark Thomson, Executive Chair of Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI), which is the primary UK funder of MAGIS-100, said, “This initiative is an exciting opportunity, both for the U.K. and the U.S., to collaborate in new technologies for fundamental science. There is huge potential in applying quantum technologies to our scientific mission to uncover the secrets of the universe.”

MAGIS-100 will be vertically mounted in a 100-meter-deep access shaft built for a neutrino experiment at Fermilab many years ago. Scientists will cool strontium atoms to close to absolute zero temperature and drop them down a vacuum tube. Laser beam pulses traveling between mirrors at the opposing ends of the vacuum tube will hit the strontium atoms. This will cause the atoms, acting like tiny atomic clocks, to simultaneously move at two different velocities and exist at two different states. Scientists will measure and compare signals to look for the superposition of two quantum states, pushing the boundaries of how far an atom can be driven apart from itself. They’ll also look for deviations that could be caused by ultralight dark-matter particles interacting with the atoms.

MAGIS-100 is part of Fermilab’s quantum science initiative. Universities working on the Atom Interferometer Observatory and Network, also known as AION, a flagship U.K. project that aims to use cold-atom interferometry for fundamental science, have been involved in MAGIS-100 from the beginning. AION collaborators are working with Stanford and Northwestern universities to develop several optics components for the experiment. They are providing the cameras that will record interference patterns of fluorescent light emitted by strontium atom clouds hit by laser light. They are also fabricating critical optical components, needed for the experiment’s mirror systems, and working on the data acquisition system.

Fermilab’s MAGIS-100 collaborators, with their know-how and experience in planning, constructing and running large-scale experiments, are working with AION collaborators to scale up cold-atom interferometry, which started as small, university-based experiments.

“What is special about this collaboration is how we are working together. We are expanding Fermilab’s expertise in working with cold atoms while bringing cold-atom interferometry into a large-scale experiment,” said Robert Plunkett, Fermilab’s project scientist for MAGIS-100.

In addition to the UKRI funding, the MAGIS-100 project is also supported by a $9.8 million grant from the Gordon and Betty Moore Foundation and funds from the DOE Office of Science’s Office of High Energy Physics through the QuantISED program,

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The 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.

Wilson Hall, the iconic building that serves as the heart of the U.S. Department of Energy’s Fermi National Accelerator Laboratory’s Batavia campus, is now open to the public.

Visitors are welcome to experience the science exhibits on the atrium level and eat in the café, visit the Ramsey Auditorium, the second-floor art gallery and the ground floor credit union. The art gallery may be closed at times due to special events taking place. All of these areas will be open Monday through Friday from 7:00 am to 5:00 pm.

For those wishing for a guided tour of the lab, Fermilab has begun hosting monthly public tours on the 3rd Monday of each month starting on Feb. 19th. To sign up please register here.

The spring 2024 Saturday Morning Physics program for high school students begins Jan. 27 with a live driving tour. The program runs every Saturday through April 13. Registration is still open and required.

The Lederman Science Center continues to be open to the public Monday through Friday 9:00 am – 5:00 pm and Saturdays from 9:00 am – 3:00 pm.

REAL ID-compliant identification is required for all visitors to enter the site, which provides visitors with access to Wilson Hall, the Lederman Science Center, walking trails, and the bison herd for viewing.

When visiting Wilson Hall parking is available on the west side of the building. Please check the Covid Community Levels before visiting for any requirements.

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The 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.

Public message from the Fermilab director on Fermilab access

Dear colleagues and friends of Fermilab,

Throughout our history, Fermilab has had a tradition of being open and welcoming to staff, users, the scientific community and neighbors. However, we know that for some members of our community, this tradition has not been upheld over the past few years. My team and I vowed to do better. After all, Fermilab must foster a culture of openness and collaboration in order to keep leading the country — and the world — in particle physics research, education and outreach.

I am pleased to share a significant step forward in these efforts. Today, Jan. 23, 2024, Fermilab is reopening our iconic Wilson Hall to the public.

As of today, any member of the public who enters the site with proper identification has access to portions of Wilson Hall: the atrium and café on the main floor, Ramsey auditorium for public conferences, the credit union on the ground floor, and the Fermilab Art Gallery on the second floor.

This is a development many months in the making, and I appreciate your patience as my team and I worked diligently to make this happen. I am deeply appreciative of the DOE Headquarters and Fermilab Site Office for their partnership with us that made this possible and the Site Access Steering Committee for their ongoing work to ensure the lab is open and accessible to the community, users and affiliates.

Additional recent developments

Since my last letter in May 2023, we have made solid progress in improving site access. In October, a review of Fermilab site access controls and requirements was conducted by peer labs, and a Site Access Steering Committee was established to work with teams across the lab to ensure cross-functional collaboration in determining the vision for the site access end state, objectives, goals, and action steps needed to achieve the vision, and the accompanying communications for each milestone achieved.

We also opened the Aspen East Welcome and Access Center to provide a location for our team to help collaborators and business visitors complete the badging process. And in November 2023, we benchmarked site access policies and procedures against other comparable DOE laboratories and restarted public tours, more of which will come in 2024.

Access to additional buildings was enabled for all badged employees, users and affiliates. The buildings included in this first phase were IERC, IARC, ICB and FCC. More buildings, including SiDET, will come in future phases. An online single-form access request became available, streamlining the access request process for our collaborators, visitors, and guests. And we have established robust communications with employees and stakeholders to gather input and keep people informed.

As we have done for over a year, Fermilab is pleased to continue to welcome onto the Fermilab campus public visitors showing proper identification for site access. The Batavia and Warrenville gates are open for walkers, bikers, dog walkers, and visitors to enjoy the campus, visit our bison, tour the science experiments and displays in the Lederman Science Center, hike our restored prairie trails, and now, visit the Wilson Hall atrium, art gallery and credit union. Saturday Morning Physics with live tours and other STEM activities returned to the Ramsey Auditorium in early 2023.

In the 2023 calendar year, we are proud to have welcomed over 19,000 people to Fermilab’s site, including 11,000 business visitors, 4,000 users and 2,000 contractors. Separately, over 5,500 public visitors came on site to enjoy our science exhibits, nature trails and bison.

Please check the website for the lab’s current site access requirements.

Progressing toward the future

As outlined in my previous letter, Fermilab is a federal institution and is therefore required to implement federal regulations and U.S. Department of Energy requirements that have been established for all DOE National Laboratories. These requirements have shifted in the last decade and in response to the COVID-19 pandemic. Like similar labs, we believe we should strive to provide a welcoming environment for our scientific and community partners while ensuring safe and secure operations.

While we have made progress toward these objectives, the job is not complete. We are still working on several of our goals, including further streamlining the access request form and approval processes, and defining our desired future state with a project plan. We still intend to provide regular reporting on site access metrics and trends as well as the project plan’s progress via email and messages to collaborators and neighbors.

We are deeply committed to our culture of openness, and we are also deeply committed to the safety of our employees, subcontractors, users, affiliates, visitors, and neighbors and to the security and stewardship of the world-class facilities, infrastructure and data at the lab.

I continue to thank you for expressing your views, concerns and opinions with me. The dedication and passion shown by our employees and community members demonstrates how seamlessly integrated Fermilab is as an institution, and it is extremely valuable and appreciated.

With best regards,

Lia Merminga