Laser induced breakdown spectroscopy application in joint European torus

Abstract

The results on the first successful application of Laser Induced Breakdown Spectroscopy (LIBS) for remote in situ diagnostics of plasma facing components (a deposited layer on a divertor tile) in Joint European Torus (JET) are presented. The studies were performed with an available JET EDGE LIDAR laser system. For in-depth analysis of deposited layers on JET divertor tiles, a number of laser shots were applied onto the same divertor place without laser beam displacement. The spectral lines of D, CII and impurity elements (CrI, BeII, …) were identified in a wide spectral range (400-670 nm). With the increase in a number of laser shots applied onto the same divertor place, we observed consecutive changes in spectral line intensities of deuterium, carbon, and impurities with the appearance of spectral lines of tungsten substrate (WI). In-depth analysis of deposited layers on JET divertor tiles was made on the basis of the spectral line behaviour in reference to the applied laser shots. The possibility of surface cartography with laser beam displacement on the tile surface was demonstrated as well. Based on the results obtained, we may conclude that LIBS method is applicable for in situ remote analysis of deposited layers of JET plasma facing components.

LIBS study of ITER relevant tungsten–oxygen coatings exposed to deuterium plasma in Magnum-PSI

“…Laser induced breakdown spectroscopy (LIBS) has been shown to be a promising method for the in-situ fuel retention monitoring in tokamaks [20][21][22][23][24][25] and linear plasma devices [26][27][28][29]. However, the line intensities in LIBS spectra depend not only on the coating composition but also on morphology and crystalline phase content [30][31][32].…”

Laser-induced breakdown spectroscopy to monitor ion cyclotron range of frequency wall cleaning Li/D co-deposition in EAST tokamak

“…LIBS, due to the advantages of multi-element analyses and in-situ monitoring, can be used to analyze wall material qualitatively and monitor the changes of the wall surface condition in real time [26][27][28][29][30]. In the present paper, firstly we laboratorily simulated the special constraints of fusion environments, including high vacuum, presence of the magnetic field and different ambient gases, to investigate the effects of magnetic field and the ambient gases on laser-produced plasma with the purpose of providing some useful information for adopting LIBS technique to monitor the ICRF cleaning processes of the first wall in EAST tokamak.…”

In-situ LIBS and NRA deuterium retention study in porous W-O and compact W coatings loaded by Magnum-PSI

“…The spectrum of the light emitted from the plasma plume is used to determine the elemental composition of the ablated material. It has been demonstrated that LIBS can be used for remote in-situ determination of the hydrogen isotopes in the W based materials both in tokamaks [14][15][16][17] and linear plasma devices [18][19][20][21][22]. The determination of the absolute value of D content requires extensive calibration with different coatings.…”