Neutron interference with superconducting magnet functionality in fusion plants has been a pressing concern, but recent research suggests that this issue may have been overstated. A team of researchers from MIT has conducted experiments to investigate the effects of neutron irradiation on high-temperature superconducting magnets, and their findings could have significant implications for the development of fusion power plants.
High-temperature superconducting magnets play a crucial role in nuclear fusion power plants. These powerful magnets are essential for confining the extremely hot plasma needed for fusion reactions, which combine two hydrogen atoms to form an atom of helium, releasing a neutron in the process.
However, early tests suggested that neutron irradiation inside a fusion plant might instantaneously suppress the superconducting magnets’ ability to carry current without resistance (critical current), potentially causing a reduction in the fusion power output. This concern led researchers to investigate further.
Addressing the Concern
A series of experiments conducted by MIT graduate student Alexis Devitre and professors Michael Short, Dennis Whyte, and Zachary Hartwig, along with six others, has clearly demonstrated that this instantaneous effect of neutron bombardment is not an issue during reactor operation. The findings were reported in the journal Superconducting Science and Technology.
The Massachusetts Institute of Technology (MIT) has a long history of fostering innovation and excellence in research.
With a strong focus on science, technology, engineering, and mathematics (STEM), 'MIT researchers have made significant contributions to various fields.'
According to the National Science Foundation, MIT ranks among the top universities globally for research expenditures, with over $1 billion allocated annually.
Notable breakthroughs include the discovery of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and advancements in artificial intelligence, biotechnology, and materials science.
The Experiments
In their initial tests, researchers had irradiated REBCO tapes (rare earth barium copper oxide) and then tested them afterward. However, they decided to measure the critical current while irradiating, simulating the conditions of a fusion plant. This is when they observed a significant drop in ‘critical current’.
After conducting carefully calibrated tests, it was discovered that the drop in critical current was not caused by the irradiation itself but rather by temperature changes brought on by the proton beam used for the experiments. These temperature fluctuations would not occur in an actual fusion plant.
Conclusion
The research team conducted multiple experiments, collecting over a thousand data points and performing detailed statistical analysis to confirm their findings. They concluded that the effects observed were identical under conditions where the material was heated as when it was both heated and irradiated.
This conclusive proof eliminates the possibility of instantaneous suppression of critical current due to neutron bombardment during reactor operation. The researchers believe this finding will be a significant relief for companies pursuing fusion plant designs, including ‘Commonwealth Fusion Systems’.
Fusion power plants utilize nuclear fusion, the process by which atomic nuclei combine to release vast amounts of energy.
This technology has the potential to provide clean and sustainable energy.
Currently, several countries are actively pursuing the development of commercial fusion reactors.
One notable example is the International Thermonuclear Experimental Reactor (ITER), a collaborative project between nations aiming to demonstrate the feasibility of fusion power.
If successful, fusion power plants could potentially replace fossil fuels as a primary source of energy.
Future Research
While this specific issue has been cleared, there remains the important concern of longer-term degradation of REBCO magnets that would occur over years or decades. The research team is currently investigating this aspect, and their findings will be crucial in designing more efficient and reliable fusion power plants.
