Researchers have discovered a new way to measure the fusion power in magnetic confinement fusion devices, using the branching ratio of gamma rays to neutrons in the deuterium-tritium reaction. This breakthrough could lead to more accurate and efficient fusion power measurements, paving the way for the development of sustainable fusion energy.
That Could Transform How Fusion Power Is Measured
Among various technologies investigated for sustainable energy production, magnetic confinement fusion devices are prominent. It harnesses the power of nuclear fusion, the process that powers stars and the sun, to produce electricity.
The main way to determine fusion power in these devices today is by using absolute neutron counting, which measures the total number of neutrons created during a plasma discharge. This is one of the techniques used in fusion experiments today, but it has its limitations.
Now, a new way to do so has been discovered by the team of researchers, who propose measuring the gamma-ray-to-neutron branching ratio in the Deuterium-tritium (D-T) reaction instead. The discovery could add even more value to the research of fusion power, allowing for more precise and repeatable measurement as a result.
Realizing the Promise of Gamma-Ray Counting
Led by Marco Tardocchi from Consiglio Nazionale delle Richerche (CNR-ISTP) and University of Milano-Bicocca, the researchers have been working on using gamma rays as a diagnostic to determine fusion power.
This shares a common theme with the D-T fusion reaction where some of the energy is lost as gamma rays instead of neutrons. Counting these gamma rays accurately—a task they believed they were capable of with cutting-edge technology—would let them gain valuable information about the fusion process and, possibly, provide an alternative to neutron counting.
Yet this was not without its own difficulties. The level of the gamma rays are much lower than that of neutrons, so the neutron flux background held it significantly harder to make a good measurement for them. These hurdles had to be circumvented, developed for this team new methods and possibilities in order to discriminate exactly energy as well as spectral intensities of the resulting gamma radiation.
Conclusion
This new ability for measuring the gamma-ray-to-neutron branching ratio in the D-T reaction represents a breakthrough for the continued progress of fusion power measurement. But that entirely new approach may not just confirm results of existing neutron-based techniques; it could offer a second way to measure fusion power, one that does not even depend on neutrons.
With the way forward now seemingly clear for fusion energy, the ability to accurately measure fusion power is going to be a critical component of future fusion energy technology as the world heads toward an alternative energy future. The results of this study provide a promising approach for the next-generation fusion experiments (e.g. ITER) and may lead us to hope that the realization of fusion power is a practicable, environmentally friendly energy source.
