Researchers from the Chinese Academy of Sciences have made a groundbreaking discovery about the intricate processes of material breakdown and deposition within the experimental advanced superconducting tokamak (EAST). This study sheds light on the critical challenges faced in maintaining the durability and efficiency of fusion reactors.
Unraveling the Erosion Enigma
The team, led by Prof. Luo Guangnan, reports the cause of material erosion in fusion reactors is due to high heat loads, particle fluxes and energetic ions during plasma exposure.
Through the use of a cutting-edge method known as laser-induced breakdown spectroscopy, these impurities — produced as erosion products from the walls and limiters of tokamak components which include tungsten, molybdenum, and carbon — were analyzed in more detail
The erosion of these materials occurs at rates that are determined by the interplay between the heat load, the energy of impinging ions, (= mass) and binding energy respectively. This information is vital for managing fusion reactor degradation and ensuring the lifetime of their components.
The Deposition Dilemma
The study also reveals the complex physics of how these eroded impurities then redeposit on tokamak surfaces. Skip to time lapse1 Skip to minutes (60 seconds)The deposition patterns are affected by various material properties like porosity, thermal expansion, structural compatibility and adhesion strength.
The researchers discovered a three micrometre thick layer of impurities had formed on the inside surfaces of EAST tokamak, meaning that all components substantially eroded as a result of high heat loads and energetic ions.
This finding underscores the difficulty of controlling erosion and deposition within fusion reactors to continue improving their longevity and performance. Understanding these processes will enable engineers and scientists to develop more effective strategies for counteracting the loss of material due to playing with tritium, one of the factors limiting the performance of fusion energy systems.
Conclusion
This recent work by the Chinese Academy of Sciences team represents a milestone as it reveals, for the first time, many details about how materials are eroded and deposited in fusion reactors. This is significant because of the potential to improve the longevity and performance of fusion power plants, which will help drive sustainable energy production forward in the future.
