Journal Link: Science, 388, 180-185 (2025)

Newswise — When astronomers point their telescopes to the heavens, they tend to look toward the light. They may search for the pin pricks of shining stars, the billowing of cold gas clouds, the faint heat of a star nursery or the rhythmic blaze of a pulsar. These faint signals of light beckon in a universe that is mostly dark.

In fact, the visible bits only account for 5% of the universe, while the dark side makes up the other 95%.

Now, an ongoing experiment at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility is aiming a spotlight into this so-called hidden dark sector. It aims to uncover hints of particles that interact with the dark by catching their light. 

“You underestimate the power of the dark side.”

Most of our universe is currently thought to be composed of dark matter and dark energy. While the dark sector isn’t visible to light microscopes, its existence is inferred by how it affects the stars and galaxies we study.

Currently, it’s thought that fully 27% of our universe is dark matter. This is matter that, as far as we know, isn’t made of the ordinary particles found in the Standard Model, the theoretical framework that nuclear physicists use to describe the subatomic particles that build our visible universe, such as protons and neutrons.

According to Liping Gan, the Jefferson Lab Eta Factory (JEF) experiment aims to capture hints of particles that connect the light and dark sides. Gan is a professor at the University of North Carolina, Wilmington, and a spokesperson for the JEF experiment. She says one of the goals of the experiment is to produce and capture hints of dark matter particles.

“One of the first ones is to search for dark gauge bosons. And that will give us some clue about the properties of the dark sector,” she said. 

If they do exist, dark gauge bosons would be rare examples of particles that can interact with the ordinary particles described in the Standard Model, as well as the mysterious dark matter particles.

To search for these bosons, ironically, the physicists will be looking for faint signals of light. 

“There’s no such thing as ‘the unknown’, only things temporarily hidden, temporarily not understood.”

The experiment will be carried out with the Continuous Electron Beam Accelerator Facility, a DOE Office of Science user facility accessed by more than 1,700 nuclear physicists worldwide to study the nature of matter.

The original GlueX Forward Calorimeter, as installed in Jefferson Lab’s Experimental Hall D. (Aileen Devlin / Jefferson Lab)

In the experiment, the CEBAF accelerator will generate a beam of energetic electrons and direct them into a diamond crystal. There, the electrons stimulate the diamond to release highly energetic light particles, or photons. These tiny but mighty particles of light then barrel into a target made of hydrogen. 

Hydrogen atoms are the simplest element to explore: a single proton makes up the atom’s nucleus, while the motion of a single electron forms the atom’s outer perimeter. The interactions of those photons with hydrogen’s protons spawn additional particles that will then enter detectors, where many of them can be measured.

JEF experimenters are most interested in producing the eta (η) meson. Like the proton, the η meson is made of a combination of smaller particles called quarks and gluons. But unlike the proton, the η isn’t stable. Instead, it will fall apart, or decay, into other particles in about half of an attosecond (5×10-19 seconds).

“Then our goal becomes looking for a decay. There are very many different decay channels we are going to measure, because a different decay channel tells us a different part of the physics,” explained Gan. 

According to Simon Taylor, a Jefferson Lab staff scientist and spokesperson for the JEF experiment, the experimenters are looking for rare decays.

“And a particular rare decay that we’ve been focusing on is a four-photon final state,” he said. 

“Only 18 out of 10,000 will decay to this. Most of the etas will decay into two gammas. So that’s why we call it rare reaction or rare decays, it happens only for a small fraction of the experiment,” Gan said.

The most interesting decay channels in this experiment are when η may produce a dark gauge boson. Dark gauge bosons are thought to be both exceedingly rare and short-lived. They, too, will decay away into other particles in the tiniest of fractions of a second. 

“These other particles include photons of light. We don’t know if these dark gauge bosons exist or will be produced in these decays, but this decay mode will allow us to search for them,” said Taylor.

The researchers will sift through the data they collect to see if they can discover unexpected peaks in their data, where there are more four-photon groupings than they expect. This will trigger intensive analysis to determine if each of these “bumps” is a tell-tale sign of the η meson decay.

Justin Stevens is the Wilson & Martha Claiborne Stephens associate professor of physics at William & Mary and spokesperson for phase two of the Gluonic Excitations Experiment (GlueX-II). The JEF and GlueX-II experiments are running concurrently using the same apparatus. He explained that one of the biggest challenges the two experiments face is finding those tell-tale bumps of interest inside the ginormous amount of data that will be generated. 

For context, 50 million light photons slam into the hydrogen target every second during the run. Each one has the potential to generate a few to dozens of particles that will stream into the detectors, all at once.

“We are getting something like 5 to 10 times higher luminosity in total compared to the original phase of GlueX,” Stevens said.

Taylor said that there are also other issues that will make finding a rare bump a challenge.

“It can get confused with other reactions,” Taylor explained. “Photons are detected by reconstructing the electromagnetic showers they produce in a calorimeter.  Some tiny fraction of the time, one or more of the photons disappear down the beam line or in a hole in the detector. Or two very close showers of particles may merge in the calorimeter together.”

To ensure the researchers would be able to capture these rare reactions, they needed to optimize one of their main detectors. An upgrade would ensure the detector can measure the photons it catches to such accuracy, the physicists could be sure they are capturing signals from a potential dark gauge boson and not from the remnants of incoming photons or from other reactions.

“You can’t stop the signal, Mal. Everything goes somewhere.”

For this experiment, the JEF collaboration upgraded the existing GlueX Forward Calorimeter (FCAL) to improve its resolution and hardiness. 

A view of the FCAL system during the upgrade. (Aileen Devlin / Jefferson Lab)

FCAL originally consisted of 2,800 lead glass scintillating modules connected to photomultiplier tubes. Each module has a 4 cm square face to collect the incoming particles produced in the experiment. These modules were designed to capture incoming particles and convert them into showers of light as the particles travel down their 45 cm length. This light can then be measured by the photomultiplier tubes and converted into signals that are recorded as data.

The upgrade removed 440 of the lead glass modules at the center of the detector and replaced them with 1,596 smaller lead tungstate (PbWO4) crystals. The new crystals feature only a 2 cm square face and extend 20 cm in length. They form a central square inside the new Eta Calorimeter (ECAL) that is surrounded by 2,360 of the original lead glass modules. 

A lead glass scintillating module (left) with a lead tungstate (PbWO4) crystal (right) are shown here inside Experimental Hall D. (Aileen Devlin / Jefferson Lab)

Zisis Papandreou is a JEF experiment spokesperson and a professor and head of the physics department at the University of Regina in Saskatchewan Canada. He compared the upgraded detector to a digital camera.

“Essentially, we’re reconstructing something akin to an image. If you have a larger number of smaller pixels, you can improve the resolution in the image,” he said.

The new lead tungstate crystals are also radiation-hard, which means they can better withstand the onslaught of particles generated in experiments than the original lead glass modules. Centering the new crystal modules closest to the target allows them to take the brunt of the onslaught, protecting the lead glass modules from the highest-energy particles and resulting in a longer overall detector lifetime.

Funded by the lab, the Department of Energy and the National Science Foundation, the upgrade of FCAL to ECAL cost about $5 million. Several work groups at the lab also contributed to the upgrade, including the Radiation Detector & Imaging group, the Detector Support group, the Radiation Control Department, and the Fast Electronics group. 

After four years of R&D, the full-scale upgrade took about three years to complete, beginning in 2022 and wrapping up in early 2025. According to Alexander Somov, a staff scientist at Jefferson Lab and a spokesperson for the JEF experiment who led the ECAL construction, the detector has already proven its versatility.

“It is the largest lead-tungstate crystal calorimeter in the U.S., and it’s been successfully commissioned and integrated,” said Somov. “It took a few weeks to commission, and all modules are operational. It was working fine for the first run of approximately five months.”

ECAL was successfully commissioned in April 2025, with data acquired for JEF and GlueX-II in late spring and summer 2025. So far, the detector has collected about 75 days of data as counted by the Program Advisory Committee for the two experiments.

“And the first results we’re getting show that the performance of ECAL is in good agreement with our basic expectations. But there’s more analysis to come,” said Somov.

University of North Carolina Wilmington (UNCW) Physics Professor Liping Gan, George Washington University undergraduate student Olivia Nippe-Jeakins, UNCW undergraduate students Shane Whaley and Ben Simpson, Jefferson Lab Hall D Staff Scientist Alexander “Sasha” Somov, and UNCW postdoc Laveen Puthiya Veetil pose for a photo inside Jefferson Lab’s Experimental Hall D. (Aileen Devlin | Jefferson Lab)

The upgraded detector has also served as a training ground for undergraduate physics majors interested in pursuing a career in nuclear physics. In all, 28 undergraduate students from the JEF experiment’s 11 collaborating universities participated in ECAL fabrication, installation and commissioning. The project also involved three graduate students, six postdoctoral nuclear physicists and one visiting scientist. 

“These are valuable experiences to undergraduates and then later on, they go to graduate school and some of them already were talking about going to a university that has GlueX collaborators. So, the hardware work is an absolutely amazing experience for students,” said Papandreou.

“You built a time machine? Out of a DeLorean?”

The second and final run for these experiments is currently scheduled to resume this summer. In it, the collaborators also aim to collect data that may reveal new clues to our understanding of other phenomena, such as why matter beat out antimatter in the first second of the early universe.

George Washington University undergraduate Quinn Stefan, left, and graduate student Phoebe Sharp, right, monitor experiment progress inside the Experimental Hall D counting house at Jefferson Lab in Newport News, Va., on June 17, 2025. (Aileen Devlin | Jefferson Lab)

“For example, right now we see large asymmetry between matter and antimatter in the universe, and one of the goals is to search for maybe there’s some new symmetry violation beyond the Standard Model. The third goal is to understand why quantum chromodynamics (QCD) prevents quarks from being isolated via tests of fundamental symmetries at low energy,” Somov said.

Alongside these searches, the GlueX-II experiment collaborators are looking to expand their data on particles that include charm quarks, such as the J/ψ (J/psi) meson. While the more familiar protons and neutrons are made of up and down quarks, other subatomic particles include other quark flavors, such as the charm quark. These data offer a rare opportunity to look at in depth at how such particles are made.

“So that means we can do things like study J/ψ production with a lot higher statistics and look for the charm production mechanism with a lot more precision than we had before,” said Stevens.

As the collaborators prepare for their final data run, they have also already begun preparing for the next opportunity. The proposed GlueX-III run aims to increase the intensity of the photon beam. For GlueX, it achieved about 10 million photons per second, and GlueX-II has an intensity of about 50 million photons per second. The goal for GlueX-III is to slowly crank that up to around one hundred million photons per second.

“Once you understand the detector, you just drive up the rate,” Stevens said. “So, we’re going to keep pushing up the intensity as high as we can, because we just get more data. You can look at more rare decays, more rare processes.”

In the meantime, the collaborators have their hands full preparing for their next run this summer and are looking forward to what their data reveal about the light and dark sides of our universe.

Further Reading
GWU Research Magazine: The Particle Whisperers
UNCW: Undergraduates Step Into Physics Research
Technical Paper: Eta Decays with Emphasis on Rare Neutral Modes: The JLab Eta Factory (JEF) Experiment
Technical Paper: Update to the JEF proposal (PR12-14-004)
Technical Paper: Light monitoring system for the lead tungstate calorimeter in Hall D at Jefferson Lab

Newswise — The U.S. Department of Energy’s (DOE) Argonne National Laboratory made a major contribution to a high-profile experiment seeking to discover new physics. Hosted at DOE’s Fermi National Accelerator Laboratory (Fermilab), the Mu2e (muon-to-electron conversion) experiment aims to observe an extremely rare process in particle physics. The experiment is a multiyear collaboration among more than 30 institutions and 200 scientists from around the world.

An Argonne team of high energy physics scientists designed and — most recently — commissioned a crucial Mu2e subsystem called the Cosmic Ray Veto (CRV) detector. This subsystem filters out the biggest source of background noise in Mu2e. Background noise refers to signals that mimic the rare process that Mu2e seeks to detect. The commissioning tests demonstrated that the CRV detector is working properly and collecting background data.

The CRV’s development and deployment was a collaborative effort among Argonne, Fermilab, Kansas State University, University of South Alabama, University of Virginia, Northern Illinois University and University of Michigan.

“The CRV detector will enable Mu2e to more reliably and accurately detect an event expected to be vanishingly rare according to current particle physics theory,” said Yuri Oksuzian, an Argonne physicist who has played a key role in Mu2e and the CRV’s development. ​“The CRV is essential because it screens out background noise that could mimic this event. Observing even a few cases of the event would be compelling evidence of new physics.”

Searching for a muon-to-electron conversion

Since the 1970s, the dominant theory in particle physics has been the Standard Model. Widely considered a robust theory, the Standard Model describes the interactions among the fundamental particles and forces in the universe. But it leaves many big questions unanswered. For example, it cannot explain gravity or dark matter, a mysterious type of matter that cannot be observed directly.

As a result, particle physicists are searching for new theories, particles and forces beyond the Standard Model. The aim is to provide a more comprehensive understanding of the universe.

Mu2e seeks to observe a muon changing to an electron without any other particles being produced. A muon is a fundamental particle that is a heavier version of an electron. The Standard Model expects this transition to be so rare that observing it at Mu2e would be a major discovery and strong evidence of new physics.

“If Mu2e detects a muon-to-electron conversion, it would indicate that there’s a new particle or force involved in this process,” said Oksuzian. ​“The discovery would fundamentally change our understanding of how the universe works.”

Screening out cosmic-ray muons

The Mu2e apparatus directs a high-intensity beam of muons to a thin aluminum foil target. Detectors probe the target for conversion events, indicated by the presence of electrons with a precise amount of energy and momentum. Remarkably, Mu2e is expected to be 10,000 times more sensitive to conversions than previous similar experiments.

The apparatus has critical subsystems that measure background — in other words, signals that look like conversions but aren’t. A major background source is cosmic rays. These are high-energy particles from space that collide with atoms in the Earth’s atmosphere. The collisions produce showers of particles, including muons, that reach the ground.

Muons can penetrate the Mu2e apparatus and knock electrons from the aluminum foil. These free electrons can potentially have the exact energy and momentum of an electron from a conversion event. If that happens, Mu2e’s detectors will mistakenly register them as the real signal.

The CRV detector, engineered by Argonne, detects background events caused by cosmic-ray muons. It is essentially a giant cage that covers key parts of the Mu2e apparatus. It consists of 83 modules, which together weigh about 60 tons. The modules are made of thousands of plastic strips that produce light photons when muons pass through them.

Special fibers inside the strips carry the photons to sensors called silicon photomultipliers. The sensors measure the photons, indicating the exact time of the muon’s passage. If the CRV detects a cosmic muon just before an electron appears in the Mu2e apparatus, that electron is rejected from the data.

“We had to carefully design the CRV structure so that there are no gaps between the modules,” said Oksuzian. ​“The objective was to ensure that the detector would not miss any cosmic muons.”

Without the CRV, cosmic-ray muons would produce thousands of ​“fake” conversion events over Mu2e’s three-to-five-year run time. Because muon-to-electron conversions are so rare, even a small number of fake events would compromise Mu2e’s accuracy. As a result, the CRV must detect and reject 99.99% of cosmic-ray muons passing through. Argonne recently evaluated the CRV’s performance over a two-year period and found that it can meet this strict design requirement.

Commissioning the CRV at Mu2e

Recently, the Argonne team transported the CRV components to the Mu2e building at Fermilab in Batavia, Illinois, and commissioned them to detect cosmic-ray muons. The successful test enabled the CRV to fulfill a key DOE technical milestone and performance objective, helping to advance Mu2e’s commissioning. Other Mu2e subsystems will be commissioned and tested over the next year.

The experiment is expected to begin in 2027. Argonne scientists will have important roles in Mu2e operations, including the CRV, data acquisition system and analysis of datasets.

Besides Oksuzian, Argonne’s CRV team also includes Simon Corrodi, Sam Grant, Peter Winter and Lei Xia.

DOE’s Office of Science is a key supporter of Mu2e and Argonne’s CRV research and oversees Mu2e’s implementation.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology by conducting leading-edge basic and applied research in virtually every scientific discipline. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s 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, visit https://​ener​gy​.gov/​s​c​ience.

Journal Link: Physical Review Letters, 135 091401 (2025)

Newswise — In the air people breathe, the water on the Earth, the stars in the sky and more, atoms are the building blocks that make up the universe. Understanding the structure of the atomic nucleus is crucial for research with implications for astrophysics and in applications such as medical imaging and data storage.

A new study conducted by Department of Physics researchers using the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University examined titanium-50 nuclei and showed that a long‑standing explanation for where magnetism in atomic nuclei comes from does not fully work for titanium‑50. The research, which was published in Physical Review Letters, suggests that scientists may need to rethink how they explain nuclear magnetism.

“What current models propose is that magnetic strength is largely generated by spin-flip excitations, that means when flipping proton or neutron spins from up to down between so-called spin-orbit partner orbitals,” said Associate Professor Mark Spieker, a co-author on the multi-institution study. “For the first time, we showed that this type of spin-flip cannot be the only mechanism that generates nuclear magnetism.”

How it works

Current nuclear models treat protons and neutrons as individual particles that can occupy fixed energy levels. A spin-flip occurs when these particles change the orientation of their spin as they jump between levels, generating magnetic strength in the process. For many years, scientists believed that this spin-flip mechanism was mainly responsible for magnetic strengths, or signals, in atomic nuclei. Advanced computer modeling also predicted this behavior.

The FSU experiments showed something unexpected: nuclear excited states that clearly showed this neutron spin-flip structure were not the ones producing the strongest magnetic signals. In other words, having more of this neutron “spin‑flip” structure did not automatically mean a stronger magnetic effect.

What they did

The researchers conducted a neutron-transfer experiment at the John D. Fox Superconducting Linear Accelerator Laboratory, using the facility’s Tandem Van de Graaff Accelerator to direct a deuteron — a nucleus made of a proton and a neutron — beam at a thin foil of titanium-49. During the reaction, the neutron from the beam was transferred to titanium-49, producing titanium-50 and leaving a residual proton.

Scientists used the Super-Enge Split-Pole Spectrograph at the Fox Lab to measure the different angles at which the proton was emitted in the reaction, allowing them to analyze how the neutron was transferred to titanium-49.

“You could say that the deuteron beam hits the titanium-49, transfers a neutron, and in this process kicks it up a set of stairs. Depending on the nucleus, that set of stairs looks very different,” Spieker said. “With the spectrograph, we can measure how high the different steps are. How high we get up the set of stairs depends on the excitation energy that we give to the nucleus.”

They combined their results with previously published electron- and proton-scattering data and with data from new photon-scattering experiments conducted at collaborating universities. By combining all these approaches, they were able to closely examine how neutrons flip their spin and how much those flips contribute to the nucleus’s overall magnetic behavior.

The researchers saw that the magnetic signal observed in their experiments was not of the same strength as models predicted — a sign that something else must be contributing to the magnetic signals they measured for titanium-50.

“Without combining all these data sets, the story cannot be stitched together cleanly,” said Bryan Kelly, a graduate student at FSU and study co-author. “Seeing the other magnetic excitations, that the other probes are sensitive to, allowed us to conclude that the spin-flip mechanism between spin-orbit partners is not the sole factor of magnetic strength generation.”

Why it matters and future directions

The study’s results challenge long-standing assumptions about the magnetic behavior of nuclei. Improving scientific understanding of the structure of atomic nuclei will refine current models used across nuclear physics and astrophysics and will help to link these with models used in high-energy physics. Such combined efforts between different fields of physics lead to a better understanding of the building blocks of ordinary matter that shape our universe.

“Developing a better understanding of the universe is exciting and fascinating on its own, and as we learn more, we can possibly apply these new insights to all sorts of new ideas,” Spieker said. “All ordinary matter is made of atomic nuclei, so the more we understand these ‘building blocks’ of nature, the more possibilities we have for what we can use them for to benefit society and drive progress.”

In future studies, the researchers plan to examine what accounts for the unexplained magnetism in titanium-50.

“This research showed that we cannot rely on magnetic strength measurements alone to understand excited states of nuclei,” Kelly said. “Magnetic strength is spread out across several nuclear states and understanding why will require further investigations of the nucleus.”

Acknowledgements

Researchers from Florida State University, the Technical University of Darmstadt in Germany and the Triangle Universities Nuclear Laboratory in North Carolina at Duke University contributed to this study.

This research was supported by the U.S. National Science Foundation, the U.S. Department of Energy Office of Science, the German Research Foundation, the Institute of Atomic Physics in Romania, the Romanian Ministry of Research and the Romanian Government.

 

BYLINE: Michelle Alvarez

For Immediate Release_

March 23, 2026
Contact: Michelle Alvarez
malvarez@jlab.org

A Strong Case for Weak Interactions

Jefferson Lab physicist Ciprian Gal wins prestigious DOE award to search for cracks in physics’ best theory of the universe

Newswise — NEWPORT NEWS, VA – In fifth grade, Ciprian Gal received his physics textbook a year early. The book promised to explain everything, and young Gal believed it. “I was bragging to all my friends, look at this book. It tells you everything,” Gal said. “And I’m going to know everything about it.” Decades later, Gal, a staff scientist at the U.S. Department of Energy’s (DOE) Thomas Jefferson National Accelerator Facility, is still chasing answers. His work probing the fundamental forces that hold matter together earned him a DOE Office of Science Early Career Research Award. The five-year, $2.75 million award will fund personnel and research expenses related to Gal’s work on the Measurement of a Lepton-Lepton Electroweak Reaction (MOLLER) experiment. MOLLER aims to test whether the Standard Model of Particle Physics, scientists’ current best description of how particles interact, is actually complete. Measuring Weak Charge The Standard Model explains three of the four fundamental forces that govern the universe: electromagnetism, the strong force and the weak force. Gal’s research focuses on the measurement of the electron’s weak charge, a property that describes how electrons interact through the weak force. While physicists understand the weak force reasonably well, measuring its precise effects on electrons requires extraordinary precision. The MOLLER experiment will scatter electrons off other electrons in a hydrogen target. It will measure tiny differences in how they scatter depending on the electron’s spin direction. These differences are so tiny, estimated to be 35 parts per billion, that measuring them requires utmost accuracy and control over every aspect of the experiment. “It’s a precision measurement,” Gal said. “We need to know exactly what we’re measuring, down to very fine details.” The challenge extends beyond just taking measurements. Gal and his team must account for every possible source of uncertainty, from the quantum mechanics of how particles scatter to the precise geometry of their detector. Abhay Deshpande, who mentored Gal during his graduate studies at Stony Brook University and now collaborates with him on MOLLER, attributes this precision mindset to Gal’s fundamental approach to physics. “His penchant for precision and methodical approach makes him particularly suited to this exacting research,” said Deshpande, Brookhaven National Laboratory’s associate lab director for nuclear and particle physics and Stony Brook University distinguished professor of physics. The new measurements could indicate new particles or forces that physicists haven’t discovered yet. These deviations could help answer some of physics’ biggest mysteries: Why is there more matter than antimatter in the universe? What is dark matter made of? “Whether we confirm the Standard Model’s predictions or find something unexpected, this measurement will be a major step forward,” Gal said. “Either result will teach us something fundamental about how the universe works.” A Decade of Physics at Jefferson Lab Gal’s connection to Jefferson Lab began in 2014, long before he joined the staff. Immediately after earning his Ph.D., he came to the lab as a University of Virginia (UVA) postdoc, drawn by the facility’s unique capabilities for studying the internal structure of protons and neutrons. Over the next eight years, Gal worked at the lab through partnerships with UVA, Stony Brook University and Mississippi State University. Each position as a research assistant professor helped him develop his skills in precision measurements and experimental design. In 2023, he joined Jefferson Lab as a staff scientist in Experimental Halls A/C. Throughout his career, Gal worked closely with mentors who shaped his approach to physics and collaboration. “At this point, Cip is one of the leading mid-career experts on all things relevant to the MOLLER experiment,” said Krishna Kumar, a University of Massachusetts, Amherst professor of physics and MOLLER spokesperson. “As we pivot to data collection and physics analysis, I expect he will be one of the leaders of the team driving the analysis to accomplish the goals of the experiment.” For Gal, that leadership potential stems directly from his commitment to teamwork. “The research that I want to do and the things that I want to discover can’t be done without collaboration, not only with experimental and theoretical physicists here at the lab, but also at the universities,” Gal said.

Looking Forward The DOE Office of Science Early Career Research Program, established in 2010, supports outstanding scientists at a DOE national laboratory or Office of Science user facility within 12 years of having earned their doctorate degree across disciplines including nuclear physics. The program aims to support the vision, creativity and effort of early career faculty to drive innovation in the basic science enterprise. For Gal, the award provides resources and time to tackle MOLLER’s technical challenges and prepare for the experiment’s data collection phase. “Cip is a fantastic collaborator,” said Kumar. “He communicates effectively regardless of the audience, and the fact that he acknowledges the need for collaboration demonstrates his maturity and potential for leadership.” Beyond the immediate research, Gal sees the award as validation of his approach: combining precision measurement techniques with innovative detector design to push the boundaries of what physics can reveal about nature’s fundamental workings. It also validates something simpler: persistence. “I think for these very competitive awards, it matters a lot to be able to stand out, to have something that is unique on its own,” Gal said. He applied in 2024, received feedback, refined his proposal, and won on his second attempt in 2025. “Ciprian thrives on difficult tasks,” said Deshpande. “He understands not only the award’s value to his own career but, more importantly, the visibility this recognition brings to the MOLLER project and Jefferson Lab. His persistence therefore does not surprise me, and I am delighted by his success.” For researchers working at the frontier of nuclear physics, success often means spending years preparing for measurements that take only hours or days to complete. The payoff comes when those measurements reveal something unexpected, a crack in our understanding that points toward deeper truths. Gal’s work on MOLLER continues that tradition, using precision as a tool to probe whether the Standard Model tells the whole story or whether the universe has more secrets waiting to be discovered. For a scientist who once believed a single book could explain everything, the possibility of discovering something entirely new might be even better than having all the answers.

Further Reading

https://moller-docdb.physics.sunysb.edu/cgi-bin/DocDBTest/public/ShowDocument?docid=998

https://journals.aps.org/prc/abstract/10.1103/PhysRevC.109.024323

https://arxiv.org/abs/2411.10267

Contact: Michelle Alvarez, Jefferson Lab Communications Office, malvarez@jlab.org

-end-

Jefferson Science Associates, LLC, manages and operates the Thomas Jefferson National Accelerator Facility, or Jefferson Lab, for the U.S. Department of Energy’s Office of Science. JSA is a wholly owned subsidiary of the Southeastern Universities Research Association, Inc. (SURA).

DOE’s 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, visit

Newswise — Henry Wadsworth Longfellow wrote, ​“It is difficult to know at what moment love begins; it is less difficult to know that it has begun.” If the celebrated poet were alive today, he might admit that, when it comes to vague beginnings, love is not alone.

Ask two people when the week begins, and you may get different answers. Ask scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory when one of its user facilities got off the ground, and you’ll hear a similar story.

Officially, the Argonne Tandem Linac Accelerator System (ATLAS) was commissioned in 1985, and 2025 marked 40 years of operation. Yet working in this DOE Office of Science user facility — built to reveal the structure and properties of atomic nuclei — are staff whose work predates that milestone by years.

“I came on in 1978,” said Gary Zinkann, an ATLAS principal engineer. ​“That was 47 years ago.”

Zinkann’s long tenure illustrates how ATLAS grew from theories, ideas and technological breakthroughs that enabled its planning, construction and commissioning. It also reflects a culture of continuous improvement — expanding capabilities and generating a steady stream of scientific insights.

“ATLAS stands as a testament to decades of scientific ingenuity and dedication,” said Guy Savard, ATLAS scientific director and Argonne Distinguished Fellow. ​“Its history is one of impactful discovery and continuous renewal. At ATLAS, we are always working to improve, innovate and expand our capabilities.”

A vision takes shape

ATLAS’ origins reach back to the early 1970s, when Argonne physicists set out to push the boundaries of nuclear physics research. The community was tackling fundamental questions about the forces inside atomic nuclei — the building blocks of matter. Argonne scientists envisioned a facility that would use superconducting technology to accelerate heavy‑ion beams and provide an unprecedented tool for nuclear physics studies.

At the time, the idea of a superconducting linear accelerator (linac) for nuclear physics was new. Superconducting materials lose electrical resistance at extremely low temperatures, enabling a high accelerating field at a comparatively low input power. Applying this technology to accelerators was largely uncharted territory.

Researchers, including Lowell Bollinger at Argonne and Caltech physicist Ken Shepard, who later came to Argonne, began collaborating to explore the feasibility of this approach. Their work led to the development of niobium split‑ring resonators, first successfully tested at Argonne in 1977.

“Developing the niobium split‑ring resonator is arguably the major technological breakthrough that made ATLAS possible,” said Benjamin Kay, a group leader at ATLAS. ​“They would ultimately become the technological backbone for the entire facility.”

These resonators, cooled with liquid helium, demonstrated the potential to accelerate heavy ions with unprecedented efficiency. Building on this breakthrough, Argonne scientists constructed a prototype superconducting ​“booster” linac, consisting of 24 resonators. The booster accelerated an ion beam delivered by Argonne’s existing tandem Van de Graaff accelerator, in use since the 1960s, and its negative‑ion source.

“The booster linac was the first part of what later became ATLAS,” said Zinkann, who retired in 2016.

Beginning operation in 1978, the booster served as a testbed for the split-ring resonator technology, allowing scientists to refine designs and address technical challenges.

“It was a very active time: designing, testing, troubleshooting,” said Zinkann. ​“And in the middle of all that, researchers were doing experiments too!”

By the early 1980s, the booster linac had logged more than 10,000 hours of beam time, much of it for experiments conducted by users visiting Argonne from other institutions. These early successes demonstrated the feasibility and promise of superconducting linacs for nuclear physics research and gave Argonne the confidence to build a full‑scale facility.

With funding from the U.S. Congress, construction of ATLAS began in the early 1980s. ATLAS would combine the booster with a second linac — also using split‑ring resonators — and new ​“target areas” equipped with detectors to collect detailed experimental data on the accelerated ion beams.

In 1983, Bollinger, then director of ATLAS, wrote to the Argonne community: ​“Scientists from all over the world will use it to expand the boundaries of research into the forces that hold together atomic nuclei.”

That aspiration helped establish ATLAS as a global hub for nuclear physics research.

The final stages of ATLAS’ construction included fabrication and installation of the superconducting resonators for the new linac (dubbed the ​“ATLAS linac” to distinguish it from the older booster linac), expansion of the liquid helium refrigerator and cryogenic plumbing system, and expansion of the computer control system to manage the new linac and beamlines. The team completed the project on time and within budget.

Building a foundation

The ATLAS facility quickly became a global center for nuclear physics research, hosting a growing community of scientists and delivering high‑quality beams for studies of nuclear structure, astrophysics and fundamental interactions. By the late 1980s, ATLAS was serving hundreds of researchers each year, providing beams of stable isotopes for experiments probing the quantum structure of nuclei and the processes that forge elements in stars.

But even in the facility’s early years, ATLAS leadership was looking ahead.

“Almost immediately after the commissioning, ATLAS leaders announced plans to replace its negative-ion source with a positive-ion source,” said Kay.

Initially, ATLAS used a negative‑ion sputter source to generate ion beams, which were accelerated and stripped to positive ions in the tandem Van de Graaff accelerator for subsequent acceleration in the linacs. Installing a positive-ion source would eliminate a need for the Van de Graaff, improving performance and allowing the facility to access the heaviest elements.

As with the booster in the 1970s, Argonne scientists and engineers collaborated to design and build what they needed. Those efforts led to the development of a new generation of ​“quarter‑wave” resonators to support the positive‑ion source.

“There’s no catalog for ordering positive‑ion sources for superconducting linear accelerators,” said Zinkann.

The Positive Ion Injector (PII) was completed and brought online in 1992. Though only seven years after ATLAS’ 1985 commissioning, PII expanded ATLAS’ capabilities by enabling beams of some of the heaviest elements, including uranium, and increased available beam currents for lighter ions. The 1960s‑era tandem Van de Graaff accelerator still served as an injector until its retirement in 2014. Its former space at ATLAS now houses stopped-beam experimental stations.

New additions

Expanding ATLAS’ capabilities widened its scientific impact. Early instruments enabled studies of nuclear reactions inside stars, shedding light on the processes that created most elements and the role of nuclear reactions in stellar evolution. Other ATLAS‑enabled efforts probed the heaviest elements and the limits of nuclear stability.

“No two days were alike,” said Zinkann. ​“A lot of times, our work was about seeing a need, finding a way to fulfill it, and then we’d see the next need and get started on that. Over time, that can make a big difference.”

Advanced instruments for nuclear structure and reaction studies were developed and deployed, including:

• Fragment Mass Analyzer, brought online in 1992 for high‑precision measurements of nuclear masses and decay processes.
• ATLAS Positron Experiment (APEX), commissioned in 1993 to study electrons and positrons emitted during heavy‑ion collisions.
• Canadian Penning Trap, which began operations in 2000 for high‑precision mass measurements of exotic nuclei.

“Like all of our instruments at ATLAS, these were wise investments that continue to pay scientific dividends today for researchers, the public and the world at large,” said Walter Wittmer, ATLAS operations director.

In 1997, the ATLAS team installed and commissioned Gammasphere, one of the world’s most powerful gamma‑ray spectrometers for nuclear structure research. Gammasphere collects data on gamma‑ray emissions following heavy‑ion fusion reactions, enabling high‑precision studies of nuclear shapes, decay processes and the forces that bind protons and neutrons. Its arrival allowed scientists to explore the quantum structure of nuclei and phenomena such as nuclear superfluidity and shape coexistence.

In cooperation with DOE and other partners, ATLAS was a finalist in the 1990s to host a new facility dedicated to rare‑isotope beams. Although DOE ultimately selected Michigan State University for that facility, ATLAS expanded in complementary directions and continues to grow its role in rare‑isotope science.

Expanding capabilities

In 2009, ATLAS commissioned the Californium Rare Ion Breeder Upgrade (CARIBU) system. Led by Savard and Richard Pardo, then ATLAS’ operations manager, CARIBU enabled production of neutron‑rich isotopes for experiments by harnessing the fission of californium‑252 to generate rare isotopes for acceleration.

“Adding CARIBU to ATLAS enabled the production of neutron‑rich isotopes that were previously inaccessible, opening new avenues for nuclear physics research,” said Savard. ​“CARIBU was particularly valuable for studying nuclear reactions that occur during supernova explosions and neutron star mergers.”

CARIBU allowed researchers to examine nuclear reactions involved in the rapid neutron‑capture process (r‑process) — a key mechanism that creates heavy elements such as gold, platinum and uranium during supernovae and neutron star mergers.

ATLAS continued to add detectors and systems for a broader range of experiments, including:

These projects also gave ATLAS engineers opportunities to innovate. HELIOS, for example, incorporates a solenoid magnet from a hospital’s decommissioned MRI scanner.

“Never underestimate what a top‑rate engineering team can do,” said Kay.

Another major addition was the Gamma‑Ray Energy Tracking In‑beam Nuclear Array (GRETINA), a precision gamma‑ray detector for high‑resolution studies of nuclear structure. Built by the U.S. nuclear physics community, GRETINA arrived at Argonne in 2013 for the first of what would ultimately be four experimental campaigns, the last of which ended in 2025. In between campaigns at ATLAS, it was installed at other accelerator facilities. GRETINA collected detailed data on gamma rays emitted during nuclear reactions, providing insights into nuclear forces and structure. Argonne scientists were instrumental in developing GRETA (Gamma‑Ray Energy Tracking Array), a next‑generation detector that will eventually replace GRETINA at ATLAS. GRETA will provide 3D tracking of gamma‑ray paths and energies for even more precise studies.

“Throughout its recent history, ATLAS has remained at the forefront of nuclear physics research, enabling studies of rare isotopes, nuclear reactions and fundamental symmetries,” said Wittmer. ​“The facility’s research programs continue to address key questions in nuclear astrophysics, nuclear structure and the properties of exotic nuclei.”

ATLAS further expanded its capabilities in 2023 with the installation of the ATLAS Material Irradiation Station (AMIS), which is used to emulate material damage in nuclear reactors. AMIS uses some of the accelerator’s lowest energies to deliver heavy ions that quickly degrade the material properties — without the radioactivity associated with irradiation in a reactor — making the development of new reactor materials safer and more efficient.

Today, ATLAS hosts researchers from across the U.S. and around the world, providing more than 6,000 hours of beam time annually.

“ATLAS has maintained strong engagement with its user community, hosting workshops, meetings and collaborative research projects to ensure that its capabilities align with the needs of scientists worldwide,” said Savard. ​“We move in the directions that will allow our users to deepen the scientific questions they can answer using ATLAS.”

Innovating for the future

Forty years after commissioning, ATLAS continues its tradition of continuous improvement to stay at the forefront of rare‑isotope research.

The team is installing and commissioning nuCARIBU, an upgraded version of the original CARIBU system, that will provide a reliable, on‑demand supply of radioactive isotopes for experiments while simplifying maintenance and improving operational efficiency. nuCARIBU will rely on neutron‑induced fission of uranium to produce isotopes and, for the first time, will allow the source to be turned off when not needed.

ATLAS is also preparing for the next generation of nuclear physics research through the N=126 Factory, an experimental system designed to provide beams of rare, neutron‑rich radioactive isotopes of very heavy elements. These isotopes are difficult to generate by other means and are important for understanding how the heaviest elements in the universe are made.

And to make the most efficient use of these new capabilities, ATLAS is pursuing a multi‑user upgrade that will enable the facility to deliver beams to two experimental stations simultaneously — one stable beam and one rare-isotope.

ATLAS’ beginning may be hard to pin down, and its history is one of continuous change. But its culture of improvement, expansion and excellence has put it on secure footing for tomorrow.

“The history of ATLAS is a story of growth, adaptation and scientific excellence. That will also be its future,” said Savard. ​“This facility’s ability to innovate and grow from its ambitious origins has allowed ATLAS to remain a vital resource for nuclear physics research, even as the field has evolved. As ATLAS looks to the future, it is well‑positioned to tackle the next generation of scientific challenges, continuing its legacy of discovery and its mission to unlock the secrets of the universe.”

Argonne Tandem Linac Accelerator System

This material is based upon work supported by the U.S. Department of Energy (DOE), Office of Science, Office of Nuclear Physics, under contract number DE‐AC02‐06CH11357. This research used resources of the Argonne Tandem Linac Accelerator System (ATLAS), a DOE Office of Science User Facility.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology by conducting leading-edge basic and applied research in virtually every scientific discipline. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s 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, visit https://​ener​gy​.gov/​s​c​ience.

Newswise — MINNEAPOLIS / ST. PAUL (03/18/2026) — University of Minnesota Twin Cities researchers working on the Super Cryogenic Dark Matter Search (SuperCDMS) experiment are part of a team who successfully cooled the experiment to its base temperature—the temperature required for the superconducting detectors to become operational, which is hundreds of times colder than outer space.

Reaching base temperature marks a major transition for SuperCDMS, from construction and installation to commissioning and science operations. For SuperCDMS, that temperature is thousandths of a degree above absolute zero, where atomic and molecular motion ceases.

The experiment is designed to detect dark matter particles—mysterious particles that make up 85 percent of all matter in the Universe—that are already passing through Earth. Dark matter remains strange and illusive but tremendously important to our understanding of nature, from the most fundamental particles to origins and evolution of the Universe.

“Getting to base temperature is a major milestone in a years-long campaign to build a low-background facility capable of housing our sensitive cryogenic solid state detectors,” said Priscilla Cushman, a professor in the University of Minnesota School of Physics and Astronomy and the Spokesperson of SuperCDMS. “At these extremely low temperatures, our installed detectors can now scan a whole new region of parameter space where the lightest dark matter particles may be lurking.”

The University of Minnesota team designed, procured, and assembled the low background shield that protects the detectors from trace radioactivity and neutrons produced by high-energy cosmic rays in the cavern walls. The four-meter tall, four-meter-diameter cylindrical enclosure is made of layers of ultra-pure lead to stop the gammas and high-density polyethylene to moderate the neutrons. 

In addition to major roles in the installation and cooldown of the experiment, University of Minnesota researchers have developed new reconstruction algorithms and analysis techniques designed to rapidly extract dark matter signals from the data that will be flowing in a few months. The group is at the forefront of the science effort, with the help of School of Physics and Astronomy Assistant Professor Yan Liu, who is the Analysis Working Group Chair for the experiment.

The SuperCDMS experiment is sited at SNOLAB, a research facility located roughly 6,800 feet underground in an active nickel mine near Sudbury, Ontario. Buried at this depth, the experiment is protected from cosmic rays and other background particles that could drown out the faint signals scientists are trying to observe.

With base temperature achieved, the collaboration will move into detector commissioning, a months-long process of turning on, calibrating and optimizing each detector channel. Beyond dark matter, SuperCDMS will allow scientists to study rare isotopes, probe energies no one has measured before and maybe uncover entirely new kinds of particle interactions.

The SuperCDMS experiment is a joint project of the U.S. Department of Energy Office of Science, the U.S. National Science Foundation, the Canada Foundation for Innovation and the Natural Sciences and Engineering Research Council of Canada.

In addition to Cushman and Liu, the University of Minnesota team includes postdoctoral researchers Shubham Pandey and Himangshu Neog, research scientist Scott Fallows, and graduate students, Zachary Williams, Elliott Tanner and Chi Cap—all from the School of Physics and Astronomy.

For more information about the SuperCDMS experiment and collaboration, visit the SLAC National Accelerator Laboratory website. Read the news release on the SLAC website.

BYLINE: Lauren Biron

Newswise — Although dark matter makes up most of the mass in our universe, it has never been directly observed. To hunt for lighter dark matter and other rare phenomena, researchers must solve a puzzle in their supersensitive detectors: an unexpected number of low-energy events, called the “low-energy excess” or LEE, that can obscure the rare signals they seek.

In a study published on Dec. 30, 2025, in Applied Physics Letters, researchers with the TESSERACT (Transition-Edge Sensors with Sub-EV Resolution And Cryogenic Targets) experiment identified one of the culprits behind the low-energy excess. They found that the noise comes not from the electronics or the surrounding environment, but from tiny bursts of vibrational energy within the silicon crystal of the detectors themselves. And the thicker the silicon, the more LEE events there are.

Since at least some LEE events come from tiny changes in the detector material itself, researchers estimate they also cause problems in superconducting qubits, the sensitive building blocks of quantum computers that are often made of silicon. The bursts of energy can create “quasiparticles” that disturb a qubit’s fragile quantum state, causing it to decohere or fail. So even in carefully shielded quantum systems, some errors could be coming from inside the house.

“Quantum computers could perform calculations our current systems can’t, but only if people can make qubits that are stable,” said Dan McKinsey, the director of TESSERACT and a scientist at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), which leads the experiment. “Because the detectors we use for our dark matter experiment have a similar backbone to what is in qubits, by understanding a problem in particle physics, we’re also getting information on how to improve the quantum computing side.”

To pinpoint where LEE events were coming from, TESSERACT collaborators fabricated superconducting phonon sensors (which pick up quantum vibrations, or phonons) on two nearly identical silicon chips that were 1 and 4 millimeters thick. In both detectors, the number of events decreased over time as they were cooled, and the thicker chip saw four times as many low-energy events — pointing to the volume of silicon itself as the source, rather than outside causes.

Now that the scientific community knows the number of LEE events relates to how thick the silicon is, some groups will be able to improve their sensors simply by scaling back how much silicon they use. But it’s still just the first step in understanding exactly what causes the bursts of energy and finding an engineering solution to get rid of the background noise completely.

“Superconducting qubits for computers are designed to ignore the environment so that their quantum state survives,” said Matt Pyle, a TESSERACT collaborator, associate professor at UC Berkeley, and researcher at Berkeley Lab. “In contrast, our photon and phonon sensors use similar technology, but they’re designed to be incredibly sensitive to their environment so that they can sense dark matter. That makes our detectors unique and powerful tools for diagnosing environmental sources that cause decoherence and limit quantum computers.”

During the experiment, TESSERACT’s thinner detector also achieved a world-leading energy resolution of 258.5 millielectronvolts. That means it could distinguish between two events with energies differing by only a few hundredths of an electronvolt, several times smaller than the amount of energy carried by a single particle of visible light. That precision will allow scientists to distinguish extremely faint signals from background noise, essential for tracking down dark matter.

TESSERACT is currently in the prototype and construction phase, and will eventually be installed in France’s Modane Underground Laboratory. The TESSERACT collaboration also includes researchers at Argonne National Laboratory, Caltech, Florida State University, IJCLab (Laboratoire de Physique des 2 Infinis Iréne Joliot-Curie), IP2I (Institut de Physique des 2 Infinis de Lyon), LPSC (Laboratoire de Physique Subatomique et de Cosmologie), Texas A&M University, UC Berkeley, the University of Massachusetts Amherst, the University of Zürich, and QUP (the International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles).

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Lawrence Berkeley National Laboratory (Berkeley Lab) is committed to groundbreaking research focused on discovery science and solutions for abundant and reliable energy supplies. The lab’s expertise spans materials, chemistry, physics, biology, earth and environmental science, mathematics, and computing. Researchers from around the world rely on the lab’s world-class scientific facilities for their own pioneering research. Founded in 1931 on the belief that the biggest problems are best addressed by teams, Berkeley Lab and its scientists have been recognized with 17 Nobel Prizes. Berkeley Lab is a multiprogram national laboratory managed by the University of California for the U.S. Department of Energy’s Office of Science.

DOE’s 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 energy.gov/science.

Newswise — NEWPORT NEWS, VA – The U.S. Department of Energy (DOE) Advanced Research Projects Agency-Energy (ARPA-E) has selected DOE’s Thomas Jefferson National Accelerator Facility to lead two research projects that will develop new technologies for better managing the waste from nuclear power plants. The $8.17 million total in grants come from the Nuclear Energy Waste Transmutation Optimized Now (NEWTON) program.

The goal of both projects is to improve existing particle accelerator technologies, one of Jefferson Lab’s key areas of expertise, and repurpose them for applications beyond fundamental research.

“Based on our own success in developing cutting-edge accelerator technologies to enable scientific discoveries, we believe that there is a contribution we can make with the experience we have gained over the last few decades,” said Rongli Geng, who is a principal investigator on both grants. Geng heads the SRF Science & Technology department in Jefferson Lab’s Accelerator Operations, Research and Development division.

Accelerator-Driven Systems Save the Day

According to ARPA-E, unprocessed used nuclear fuel “reaches the radiotoxicity of natural uranium ore after approximately 100,000 years of cooling. Partitioning and recycling of uranium, plutonium, and minor actinide content of used nuclear fuel can dramatically reduce this number to around 300 years.” The NEWTON program grants are aimed at enabling this recycling effort, so that it can be applied to “the entirety of the U.S. commercial used nuclear fuel stockpile within 30 years.”

This work is aimed at moving toward economic viability of transmutation of nuclear waste, a key priority of the NEWTON program. Specifically, the NEWTON grants will support the further development of accelerator-driven systems (ADS). ADS can transform highly radioactive and long-lived nuclear waste into less radioactive, shorter-lived materials, while also producing additional electricity.

An ADS is composed of a particle accelerator that propels a beam of high-energy protons at a target material such as liquid mercury. As the protons interact with the target, the material “spalls” or releases neutrons that are directed at containers of spent nuclear fuel.

“These neutrons will interact with these unwanted isotopes and convert them into more manageable isotopes that you can either try out for some beneficial use or bury underground. Instead of having a lifetime of 100,000 years in storage, for example, you can shorten the storage years down to 300,” Geng said.

Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) is a state-of-the-art particle accelerator that represented a huge leap forward in efficiency when it came online for its first experiment in 1995. It was the first large-scale installation of superconducting radiofrequency technology. Today, it supports the research for more than 1,700 nuclear physicists worldwide.

SRF technology powers many of the most advanced research accelerators in the world, including CEBAF and the accelerator that powers the Spallation Neutron Source at DOE’s Oak Ridge National Laboratory. Both accelerators are DOE Office of Science user facilities that enable research in the basic and applied sciences.

Improving ADS Technology

The first project aims to amp up the SRF particle accelerator components in ADS. The focus in this grant is on boosting the components’ efficiency.

In today’s world-class research machines, SRF particle accelerator cavities are made of a pure, silver-colored metal called niobium. Niobium becomes superconducting at extremely low temperatures, a key requirement for their efficiency. The downside to that efficiency is that big research machines must be supported by separate and costly cryogenic refrigeration facilities.

Recently, Jefferson Lab and other research facilities have found that coating the inside surfaces of pure niobium accelerator cavities with tin can make these components even more efficient, allowing them to not only operate at higher temperatures but also with standard commercial cooling units. This work builds on the research and development work supported by DOE’s Nuclear Physics (NP) program and NP’s Early Career Award (ECA) program.

The $4,217,721 grant will allow collaborators from Jefferson Lab, RadiaBeam Technology and Oak Ridge National Lab to further improve the cavities. The researchers plan to test niobium-tin cavities that have specifically been designed to accelerate protons for spalling neutrons. 

“Those are based on the mature Spallation Neutron Source cavity design, but we will add the new tin material on this existing design,” explained Geng. “So that will be tested together with our partners at Oak Ridge National Lab.”

A second goal of the grant is to design new SRF cavities that feature a more complicated design but will drive the machine efficiency even higher with enhanced neutron spallation.

“We’re going to design, build and test a new class of cavities called the spoke cavities,” Geng said. “Very likely, the whole machine will be based on this SRF technology, so this is the kind of innovation that is going to be an additive value.”

The Driving Force for ADS

The second project will focus on powering up the SRF accelerator cavities inside the ADS particle accelerators. For that, the researchers will turn to a common component that also powers the pops that turn ordinary corn kernels into light and fluffy popcorn: the magnetron.

In particle accelerators, magnetrons would provide the power that the SRF cavities harness to propel particle beams. The tricky part here is that the frequency of the energy supplied by the magnetron must match the frequency of the particle accelerator cavity, which is 805 Megahertz.

“We need a lot of power – 10 Megawatts or more. That’s why the efficiency becomes very critical,” Geng said.

For the $3,957,203 grant, the team will be working with Stellant Systems, one of the major players in magnetron manufacturing, to produce advanced magnetrons that can be combined to boost performance at the design frequency. The project team also includes General Atomics Energy Group and Oak Ridge National Laboratory.

“Stellant is tasked to design and prototype this new magnetron, and we’re going to collaborate with General Atomics and Oak Ridge National Lab to do the power combining test,” Geng explained. “That’s the main objective: demonstrate the high power, high efficiency at 805 Megahertz.”

He added that this work builds on research and development work supported by DOE’s Accelerator R&D and Production (ARDAP) program. This program helps ensure that new and emerging accelerator technology will be available for future discovery science and societal applications. Its support was instrumental in developing the technologies that are now at a place where they are ready to be adapted to contribute to the goal of safely maintaining the waste materials produced in nuclear power generation.

Both projects are also already on the path to commercialization of these technologies. By including commercial entities in these initial phases, Jefferson Lab and its partners are helping to not only transfer the specialized knowledge and expertise that will make the resulting technologies successful, but they are also developing these technologies with considerations of the capabilities of companies who would be manufacturing ADS and supporting their operations.

According to Geng, “The challenge is to really translate the accelerator science from where we are right now in terms of technology readiness to where the technology needs to be for this application.”

Further Reading:
Jefferson Lab Research and Technology Partnerships Office
Jefferson Lab Dedicates Niobium-tin Particle Accelerator Prototype
Benchmarking CEBAF
Supercool Delivery: Final Section of Souped-Up Neutron Source Trucks Out of Jefferson Lab
Jefferson Lab technology, capabilities take center stage in construction of portion of DOE’s Spallation Neutron Source accelerator
Smoother Surfaces Make for Better Accelerators
Adapting Particle Accelerators for Industrial Work
Mixing Metals for Improved Performance
Conduction-cooled Accelerating Cavity Proves Feasible for Commercial Applications
Liquid Helium-Free SRF Cavities Could Make Industrial Applications Practical
Award enables research for more efficient accelerators
Microwave Popcorn to Particle Accelerators: Magnetrons Show Promise as Radiofrequency Source

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Jefferson Science Associates, LLC, manages and operates the Thomas Jefferson National Accelerator Facility, or Jefferson Lab, for the U.S. Department of Energy’s Office of Science. JSA is a wholly owned subsidiary of the Southeastern Universities Research Association, Inc. (SURA).

DOE’s 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, visit https://energy.gov/science