In the quest for safer and more powerful nuclear fusion experiments, researchers at the CEA, Institute for Research on Fusion by Magnetic Confinement in France, have made significant strides in understanding the heat load deposited in the toroidal gaps between tungsten monoblocks. This work, led by Q. Tichit, is crucial for the development of the International Thermonuclear Experimental Reactor (ITER), a global collaboration aimed at harnessing fusion power for commercial energy production.
The study, conducted on the WEST tokamak, focused on the power deposition on toroidal surfaces using various monoblock and heat loading configurations. The WEST tokamak’s high-resolution infrared camera, capable of 0.1 mm per pixel, was instrumental in monitoring the temperature distribution on the blocks. The researchers deliberately misaligned a few actively cooled ITER-like plasma-facing units (PFUs) to maximize heat loading and temperature on specific block areas.
The results, published in Nuclear Materials and Energy, revealed complex patterns in the infrared images, with strong signals in the gaps and shifted hot spots on the poloidal chamfer of the downstream component. “The experimental IR images exhibit complex patterns with strong signals into the gap (greater than measured on the top surface) and shifted hot spot on the poloidal chamfer of the downstream component featuring poloidal misalignment (where optical hot spots are expected),” Tichit explained.
The research highlights the importance of specular reflection in understanding heat loading on the toroidal edge and optical hot spots. This finding is significant because it provides insights into the cavity effect, where reflective facets of the blocks facing each other can intensify heat loading. This understanding is vital for designing more robust and efficient PFUs for ITER and future fusion reactors.
The implications of this research are far-reaching. As fusion energy moves closer to commercial viability, ensuring the safety and efficiency of plasma-facing components is paramount. The detailed analysis of heat loading in toroidal gaps can inform the design of more resilient PFUs, reducing the risk of component failure and enhancing the overall performance of fusion reactors.
For the energy sector, this research paves the way for more reliable and efficient fusion power plants. By addressing the challenges posed by heat loading in toroidal gaps, researchers can develop components that withstand the extreme conditions of fusion reactions, bringing us one step closer to a future powered by clean, abundant fusion energy. The insights gained from this study will undoubtedly shape future developments in the field, driving innovation and progress toward commercial fusion power.
