In the relentless pursuit of harnessing nuclear fusion as a viable energy source, scientists are continually refining their tools and techniques to understand and control the complex dynamics of fusion plasmas. A recent study published in ‘Atoms’ (Atoms) by Maxime Brasseur of the Université de Mons, Belgium, has shed new light on the spectral lines of osmium, a key element in the transmutation process of tungsten used in fusion reactors. This research could significantly enhance the diagnostic capabilities of fusion plasma, potentially revolutionizing the way we monitor and optimize these high-energy environments.
Tungsten, with its high melting point and resistance to neutron irradiation, is a critical material for the divertor of the International Thermonuclear Experimental Reactor (ITER). However, under the intense conditions of a fusion reactor, tungsten undergoes nuclear transmutation, forming elements like osmium. These transmutation products, when sprayed into the plasma, alter its composition and provide valuable diagnostic data about plasma conditions.
Brasseur’s work focuses on the spectral lines of five-times ionized osmium (Os VI), which are crucial for understanding plasma–wall interactions. “Monitoring osmium’s spectroscopic signals will help in understanding the dynamics of plasma–wall interactions, which are crucial for predicting material erosion and plasma contamination,” Brasseur explains. The high ionization potential of neutral osmium means its ionic species can survive in high-temperature plasmas, offering insights into plasma conditions.
The study employs two independent computational approaches: the pseudo-relativistic Hartree–Fock method including core polarization corrections (HFR+CPOL) and the fully relativistic Multiconfiguration Dirac–Hartree–Fock method (MCDHF). By comparing the results from these two methods, Brasseur and his team were able to estimate the accuracy of the new calculated radiative data. “The detailed comparison showing a good agreement between the two sets of results (within a few tens of percent for most transitions) allows us to conclude that the gAHFR+CPOL-values reported in this paper for Os VI lines can be considered to be of fairly good quality for their application in plasma diagnostics,” Brasseur states.
The implications of this research are far-reaching. Accurate transition probabilities for Os VI spectral lines will enable more precise measurements of plasma properties, such as electron temperature and density. These measurements are essential for optimizing fusion reactions and ensuring the longevity of reactor components. As Brasseur notes, “These new atomic data will thus be useful for the analysis of the spectra emitted by fusion plasmas produced in Tokamaks such as ITER.”
The commercial impact of this research is significant. Improved plasma diagnostics can lead to more efficient and cost-effective fusion reactors, bringing us one step closer to a sustainable and abundant energy source. As the energy sector continues to evolve, innovations like these will be pivotal in shaping the future of nuclear fusion and its role in the global energy landscape.
