NEW YORK — Scientists from IBM and Oak Ridge National Laboratory utilized hybrid quantum computing and artificial intelligence to model the physics within a fusion reactor. Their research, which has not yet undergone peer review, was published on the preprint server arXiv on June 29, 2024.

The work focused on the behavior of tritium within a liquid salt (FLiBe) blanket during neutron bombardment. IBM researchers stated that this blanket, composed of molten salt, surrounds the nuclear reaction inside a fusion reactor, serving as both a fuel source and a thermal shield. The team simulated nine molecular configurations of FLiBe, a material considered for tritium extraction.

During the simulations, neutron bombardment continuously altered the blanket's chemistry. The researchers conducted calculations to understand these changes. The researchers stated that if tritium bonds with fluorine in the salt, it produces corrosive tritium fluoride, which is difficult to remove. Conversely, if it binds to another tritium atom to form a gas, it naturally bubbles out.

Predicting the reaction's direction requires precise modeling of how tritium interacts with the salt, a task challenging for classical methods, according to the researchers. They further stated that this is the first time different computing elements have converged to propose the most effective method for generating tritium.

The team employed artificial intelligence on the Frontier supercomputer located at Oak Ridge National Laboratory. They also utilized quantum computing algorithms, which ran on an IBM Quantum Heron quantum processing unit in New York.

Why It Matters

Fusion reactors generate energy by fusing atomic nuclei, a process that does not produce carbon byproducts or long-lived radioactive waste. Projections indicate a single fusion reactor could generate approximately 4 million times the energy of a coal-burning facility and about four times that of a modern nuclear fission reactor. Magnetic confinement reactors, such as tokamaks, are considered a leading design for viable fusion reactors.

Tritium is a critical component for these reactors. While 44 pounds of tritium are produced globally each year, scientists typically create it in nuclear reactors by bombarding lithium atoms with neutrons. Deuterium, a hydrogen isotope found in seawater, is also used; there are an estimated 33 grams of deuterium in every cubic meter of seawater. The energy released from 1 gram of deuterium-tritium fuel is equivalent to the energy from about 2,400 gallons of oil.