Comparative Analysis of Spectroscopic Studies of Tungsten and Carbon Deposits on Plasma-Facing Components in Thermonuclear Fusion Reactors

Abstract

Studies on the erosion products of tungsten plasma-facing components (films, surfaces, and dust) for thermonuclear fusion reactors by spectroscopic methods are considered and compared with those of carbon deposits. The latter includes: carbon–deuterium CDx (x ~ 0.5) smooth films deposited at the vacuum chamber during the erosion of the graphite limiters in the T-10 tokamak and mixed CHx-Me films (Me = W, Fe, etc.) formed by irradiating a tungsten target with an intense H-plasma flux in a QSPA-T plasma accelerator. It is shown that the formerly developed technique for studying CDx films with 15 methods, including spectroscopic methods, such as XPS, TDS, EPR, Raman, and FT-IR, is universal and can be supplemented by a number of new methods for tungsten materials, including in situ analysis of the MAPP type using XPS, SEM, TEM, and probe methods, and nuclear reaction method. In addition, the analysis of the fractality of the CDx films using SAXS + WAXS is compared with the analysis of the fractal structures formed on tungsten and carbon surfaces under the action of high-intensity plasma fluxes. A comparative analysis of spectroscopic studies on carbon and tungsten deposits makes it possible to identify the problems of the safe operation of thermonuclear fusion reactors.

Raman microscopy to characterize plasma-wall interaction materials: from carbon era to metallic walls

“…Raman spectroscopy allows chemical bonds to be identified and, in particular, the presence of defects [41] and surface oxides, that will modify D and T behavior in tokamaks [42], to be detected. Other spectroscopic techniques could be used and are presented in a recent article [43]. The present review discusses the advances made in the field of Raman microscopy of PFCs materials since our 2017 book chapter [44].…”

“…The present review discusses the advances made in the field of Raman microscopy of PFCs materials since our 2017 book chapter [44]. It is presented in a way complementary to [43], in order to give a direct access to people not familiar with spectroscopy to see what could be learnt from Raman spectra, and how. We illustrate how powerful Raman microscopy technique could be to convince researchers in fusion related materials to use this technique.…”