Nuclear fission has powered our world and medical progress for decades, but some of its mysteries remain elusive.
One of the biggest puzzles? What exactly happens when the nucleus of an atom splits apart in its “neck explosion” region.
Aurel Bulgac, a physics professor at the University of Washington, is exploring this very question. He and his team set out to simulate the complex dance of particles during this critical phase of fission.
A supercomputer deals with the quantum field
To address this challenge, Bulgac’s team collaborated with researchers at Los Alamos National Laboratory (LANL).
They used the enormous computing power of the Mainframe Computer at the Department of Energy’s Oak Ridge National Laboratory (ORNL).
This was the first full-scale, multi-body microscopic simulation of nuclear neck rupture.
“Perhaps this is the most accurate and most carefully obtained explanation of the theory of neck fractures, without any assumptions and simplifications,” said Bulgac. “We have a direct forecast, which until now did not exist.”
Laws and powers of nuclear fission
For more than 80 years, scientists have proposed different models to explain fission dynamics. The classic “fluid” concept likens the nucleus to a ring of molten liquid that breaks apart and ejects particles when agitated.
But Bulgac’s findings suggest a different story.
First, the team discovered that neck fractures are not random. Instead, the place where the nucleus ends up dividing is determined well before the actual scission.
Furthermore, they found that the proton neck breaks faster than the neutron neck, meaning that the neutrons hold the neck together before it breaks completely.
Perhaps surprisingly, they confirmed the existence of scission neutrons. These are the neutrons that are effectively produced when a nucleus splits.
“There are people who say they are there, others say they are not. We see them, we don’t see them, etc.,” said Bulgac.
Their simulation not only showed that scission neutrons are real but also explained in detail where they go and how much energy they carry.
Nuclear fission and scission neutron
A group comparison revealed that the scission neutrons are produced in two different ways. Some shoot sideways, in the direction of the fission particles.
Others come from the “noses” of the particles separated by the waves of material sent out during the neck explosion.
“After we put everything together and ran the simulation, we found some things that were completely unexpected: the neutrons are coming out of the sides and towards the particles moving,” said Bulgac.
“These kinds of unique spectra are something that none of the previous models predicted. In addition, they have very high energies, so they should have different properties especially thermal neutrons.”
A very “super” computer simulation
Making such a detailed comparison was not easy. The team used the entire Summit supercomputer for nearly 1 million node hours.
Each run lasted about 15 hours and covered nuclei such as uranium-238, plutonium-240, and californium-252 under different conditions.
“The most important tool was the use of Oak Ridge supercomputers, starting with Jaguar and Titan, then Summit,” Bulgac explained. Without them, all of this would not have been possible. Absolutely impossible. ”
The mathematical design behind the simulation is something that Bulgac has been refining since the early 2000s.
Instead of tracking each particle, his method focuses on the overall distribution of particles in space, making the complex problem more manageable.
What’s next for nuclear fission?
The next big step is to test these predictions in the real world. Bulgac has begun discussions with experimentalists eager to confirm the findings.
“We used the right values for the parameters that describe this phenomenon – and nothing else. And these are the results we got,” he said. “Well, if it’s not true, there is a very big question: What’s wrong with that idea?”
It is a momentous moment. If experiments confirm the analogy, it could change our understanding of nuclear fission. If not, it opens up new research avenues.
“Right now, it’s very difficult to see what the mistake will be, but we have to wait and see,” said Bulgac. “If you make a prediction, it’s confirmed or it’s not confirmed, and you have to look and see. This is how physics progresses.”
Why is any of this important?
Understanding the limitations of nuclear fission is not just an academic task. It has practical implications for nuclear power generation, medical applications, and even our understanding of fundamental physics.
By shedding light on the process of scission and the behavior of scission neutrons, Bulgac’s work could lead to more efficient nuclear reactors or new technologies that use fission.
Publication of a group paper in a journal Physical Examination Letters has already sparked interest. Scientists around the world are eager to see where this research leads.
For those of us outside the lab, it’s a reminder of how much there is still to learn about the forces that shape our universe.
A new chapter in nuclear physics
As experiments continue to test these findings, the scientific community watches with bated breath.
Whether confirming or challenging Bulgac’s simulation, the results will undoubtedly deepen our understanding of nuclear fission.
And perhaps, in the not-too-distant future, we will look back on this research as a turning point – the moment we took back another part of the atomic world and discovered something amazing.
Who would have thought that after all these years, the simple act of splitting an atom could hold so many wonders?
The full study is published in the journal Physical Examination Letters.
—–
Do you like what you read? Subscribe to our newsletter for interesting articles, exclusive content, and the latest updates.
Check us out at EarthSnap, a free app brought to you by Eric Ralls and Earth.com.
—–
#nucleus #atom #splits #Science