MIT researchers have developed a technique that enables real-time, 3D monitoring of corrosion, cracking, and other material failure processes inside a nuclear reactor environment.

This could allow engineers and scientists to design safer nuclear reactors that also deliver higher performance for applications like electricity generation and naval vessel propulsion.

During their experiments, the researchers utilized extremely powerful X-rays to mimic the behavior of neutrons interacting with a material inside a nuclear reactor.

They found that adding a buffer layer of silicon dioxide between the material and its substrate, and keeping the material under the X-ray beam for a longer period of time, improves the stability of the sample. This allows for real-time monitoring of material failure processes.

By reconstructing 3D image data on the structure of a material as it fails, researchers could design more resilient materials that can better withstand the stress caused by irradiation inside a nuclear reactor.

“If we can improve materials for a nuclear reactor, it means we can extend the life of that reactor. It also means the materials will take longer to fail, so we can get more use out of a nuclear reactor than we do now. The technique we’ve demonstrated here allows to push the boundary in understanding how materials fail in real-time,” says Ericmoore Jossou, who has shared appointments in the Department of Nuclear Science and Engineering (NSE), where he is the John Clark Hardwick Professor, and the Department of Electrical Engineering and Computer Science (EECS), and the MIT Schwarzman College of Computing.

Jossou, senior author of a study on this technique, is joined on the paper by lead author David Simonne, an NSE postdoc; Riley Hultquist, a graduate student in NSE; Jiangtao Zhao, of the European Synchrotron; and Andrea Resta, of Synchrotron SOLEIL. The research is published in the journal Scripta Materiala.

“Only with this technique can we measure strain with a nanoscale resolution during corrosion processes. Our goal is to bring such novel ideas to the nuclear science community while using synchrotrons both as an X-ray probe and radiation source,” adds Simonne.

Real-time imaging

Studying real-time failure of materials used in advanced nuclear reactors has long been a goal of Jossou’s research group.

Usually, researchers can only learn about such material failures after the fact, by removing the material from its environment and imaging it with a high-resolution instrument.

“We are interested in watching the process as it happens. If we can do that, we can follow the material from beginning to end and see when and how it fails. That helps us understand a material much better,” he says.

They simulate the process by firing an extremely focused X-ray beam at a sample to mimic the environment inside a nuclear reactor. The researchers must use a special type of high-intensity X-ray, which is only found in a handful of experimental facilities worldwide.

For these experiments they studied nickel, a material incorporated into alloys that are commonly used in advanced nuclear reactors. But before they could start the X-ray equipment, they had to prepare a sample.

To do this, the researchers used a process called solid state dewetting, which involves putting a thin film of the material onto a substrate and heating it to an extremely high temperature in a furnace until it transforms into single crystals.

“We thought making the samples was going to be a walk in the park, but it wasn’t,” Jossou says.

As the nickel heated up, it interacted with the silicon substrate and formed a new chemical compound, essentially derailing the entire experiment. After much trial-and-error, the researchers found that adding a thin layer of silicon dioxide between the nickel and substrate prevented this reaction.

But when crystals formed on top of the buffer layer, they were highly strained. This means the individual atoms had moved slightly to new positions, causing distortions in the crystal structure.

Phase retrieval algorithms can typically recover the 3D size and shape of a crystal in real-time, but if there is too much strain in the material, the algorithms will fail.

However, the team was surprised to find that keeping the X-ray beam trained on the sample for a longer period of time caused the strain to slowly relax, due to the silicon buffer layer. After a few extra minutes of X-rays, the sample was stable enough that they could utilize phase retrieval algorithms to accurately recover the 3D shape and size of the crystal.

“No one had been able to do that before. Now that we can make this crystal, we can image electrochemical processes like corrosion in real time, watching the crystal fail in 3D under conditions that are very similar to inside a nuclear reactor. This has far-reaching impacts,” he says.

They experimented with a different substrate, such as niobium doped strontium titanate, and found that only a silicon dioxide buffered silicon wafer created this unique effect.

An unexpected result

As they fine-tuned the experiment, the researchers discovered something else.

They could also use the X-ray beam to precisely control the amount of strain in the material, which could have implications for the development of microelectronics.

In the microelectronics community, engineers often introduce strain to deform a material’s crystal structure in a way that boosts its electrical or optical properties.

“With our technique, engineers can use X-rays to tune the strain in microelectronics while they are manufacturing them. While this was not our goal with these experiments, it is like getting two results for the price of one,” he adds.

In the future, the researchers want to apply this technique to more complex materials like steel and other metal alloys used in nuclear reactors and aerospace applications. They also want to see how changing the thickness of the silicon dioxide buffer layer impacts their ability to control the strain in a crystal sample.

“This discovery is significant for two reasons. First, it provides fundamental insight into how nanoscale materials respond to radiation—a question of growing importance for energy technologies, microelectronics, and quantum materials. Second, it highlights the critical role of the substrate in strain relaxation, showing that the supporting surface can determine whether particles retain or release strain when exposed to focused X-ray beams,” says Edwin Fohtung, an associate professor at the Rensselaer Polytechnic Institute, who was not involved with this work.

This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

Looking to upgrade your wireless earbuds without reaching deep into your wallet? Our favorite earbuds for most people, the Nothing Ear (a) (8/10, WIRED Recommends) are currently marked down to just $79 when you buy them from Nothing directly. They may be cheap when it comes to dollars spent, but they have it where it counts, with great audio quality, an excellent feature set, and awesome battery life.

While the first-party offerings from both Apple and Google make for compelling options, the Nothing Ear (a) are great for both sides of the aisle. They feature painless pairing with either iOS or Android devices and have great touch controls for managing your music or volume. They’re also among the best for battery life, especially for the price, reaching 5.5 hours of play time even with noise-canceling.

The sound quality is really impressive, with custom-made 11-mm drivers that have a sound profile our reviewer described as “crip, clear, and dynamic,” so they’re perfect for listening to more open and delicate music. Jazz, classical, and acoustic songs all shine on the Nothing Ear (a), but you can use them for pop and rock and be just as happy.

They also feature impressive noise-canceling tech, with a full 45 decibels of sound reduction, which is great if you often find yourself trying to catch up on your podcasts on a busy subway. Our reviewer even appreciated them for traveling, noting that they do a good job of reducing the hum of an airplane engine.

There’s a slightly more expensive option as well, the Nothing Ear, which is currently on sale for just $99 and adds wireless charging to the case, plus a ceramic driver. That may sound appealing, but in practice, WIRED writer Parker Hall didn’t necessarily note a huge difference in performance, and the battery life is a little bit worse as a result, so we think the Nothing Ear (a) are a better value.

For under $100, the Nothing Ear (a) provide a remarkable amount of value, with great audio quality for music, excellent noise-canceling, and a platform-agnostic outlook that’s sure to appeal to anyone with lots of different devices. They easily compete with wireless earbuds at twice the price, earning them the top spot on our favorite wireless earbuds roundup.

A self-proclaimed leader of an online group linked to the violent extremist network The Com tells WIRED he is responsible for the flurry of hoax active-shooter alerts at universities across the US in recent days as students return to school.

Known online as Gores, the person says he coleads a group called Purgatory, which is offering its followers a menu of services, including hoax threats against schools—known as swatting—for just $20, while faked threats against hospitals, businesses, and airports can cost up to $50. The group also offered “slashings” and “brickings” for as little as $10, according to a review of the group’s Telegram channel by WIRED, apparently referencing real-world violence.

In recent days, however, as the incidents were reported in the media, the prices have skyrocketed, with a school swatting now costing $95 and brickings costing $35.

The group has been linked to 764, a nihilistic subgroup of The Com that conducts targeted campaigns against children using extortion, doxing, swatting, and harassment. Members of 764 have been accused of everything from robbery to sexual abuse of minors, kidnapping, and murder.

Since the swatting spree kicked off on August 21, around a dozen different universities have been targeted with 911 emergency calls, some having to issue alerts on multiple occasions after receiving multiple hoax calls. Gores tells WIRED that the group had earned around $100,000 since the swatting spree began. WIRED has not independently confirmed that figure.

As well as the confirmation from Gores, two researchers who spoke to WIRED confirmed that they had both listened to the group conducting swatting calls on audio livestreams as they happened in recent days. In at least one case, a researcher was able to intercede and call the targeted institution to inform them that the call was a hoax.

WIRED reviewed recordings of the swatting calls provided by the researchers and has been reviewing the Telegram channel run by Purgatory, where members of the group have been celebrating media coverage of their calls in recent days, including the swatting attempt on the University of Colorado Boulder on Monday afternoon.

Nicole Mueksch, a spokesperson for the University of Colorado Boulder, tells WIRED that the incident remains under investigation, adding that university police are working with “state and federal partners, including the FBI, to explore any potential leads or patterns that may be connected to other recent swatting cases across the country.”

The FBI told The Washington Post that it’s investigating and, in a statement to The New York Times, said it is “seeing an increase in swatting events across the country, and we take potential hoax threats very seriously because it puts innocent people at risk.” The agency did not immediately respond to WIRED’s request for comment.

“Knowingly providing false information to emergency service agencies about a possible threat to life drains law enforcement resources, costs thousands of dollars and, most importantly, puts innocent people at risk,” the FBI added.

The recent swatting spree began on August 21, the same day the current Purgatory Telegram channel was launched. At around 12:30 pm local time that day, the University of Tennessee at Chattanooga received a call claiming an active shooter was on campus. The school was locked down for over an hour before campus police issued an all-clear at 1:51 pm after no threat was found. Hours later, at Villanova University in Pennsylvania, a hoax call forced the school into lockdown as students and faculty took part in the university’s orientation mass to welcome new students.