<i>In situ</i> diagnosis of Li-wall conditioning and H/D co-deposition on the first wall of EAST using laser-induced breakdown spectroscopy

Liu, P; De-you, Zhao; Sun, Liying; Fu, Cailong; Liu, J M; Li, C; Hai, Ran; Sang, Chaofeng; Hu, Z.; Sun, Zhuo; Hu, Jiansheng; Wang, L; Chen, J L; Liang, Yong; Luo, Guang–Nan; Ding, Hongbin; Team, East

doi:10.1088/1361-6587/aace83

Cited by 17 publications

(4 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is well known that fuel retention in nuclear fusion devices is mainly derived from ion implantation and co-deposition. It has been reported that the thickness of D co-deposition is of the orders of ∼μm [15,29,30] and the depth of the D implanted in W is also mostly located in the subsurface (∼10 μm) [4,15,18,25,26]. However, for deeper D retention, such as that induced by neutron irradiation [31][32][33], the depth of D retention may reach several hundred μm or even mm, the number of laser pulses and the time required also need to be considered, the application of LID could be limited.…”

Section: Qms Ion Currents and Quantification Of D 2 And Hdmentioning

confidence: 99%

Characterization on deuterium retention in tungsten target using spatially resolved laser induced desorption-quadrupole mass spectroscopy

Lyu

Liu

et al. 2021

Phys. Scr.

View full text Add to dashboard Cite

It is still challenging to achieve the quantitative analysis with a spatially resolved measurement for a non-uniform fuel retention in Plasma Facing Materials (PFMs). In this work, a long-pulse (τ p ≈750 μs) Laser Induced Desorption-Quadrupole Mass Spectroscopy (LID-QMS) has been developed as a diagnostic approach for characterizing inhomogeneous deuterium (D) retention in tungsten (W) target exposed to D plasma for ∼1 h with the total ion flux of 4.0×10 21 D/(m 2 s) at the substrate temperature of 400 K. The behavior of desorption of trapped D during LID was analyzed. 2D-distribution features of D retention in the exposed and shadowed areas of the W-target were investigated with a lateral resolution of about 650 μm and depth resolution of approximately 175 μm. The results show that the D retention is almost uniform along lateral dimension in the D plasma exposure area with an average fluence of (2.51±0.40)×10 20 D m −2 , while the value in the shadow area is only (0.25±0.04)×10 20 D m −2 which is one order of magnitude smaller than that in the exposure region. In the depth dimension, about 86.5% of the retained D is desorbed by the first laser pulse, which indicates that the D-retention is mainly distributed in the region less than 6.6 μm based on the diffusion length. The micro-structures of W target exposed to D plasma after the long-pulse laser irradiation present swelling, blistering as well as bubble-bursting, which might be attributed to the thermodynamic interaction due to the rapid release of D particles from bulk to surface of W target during LID.

show abstract

Section: Qms Ion Currents and Quantification Of D 2 And Hdmentioning

confidence: 99%

Characterization on deuterium retention in tungsten target using spatially resolved laser induced desorption-quadrupole mass spectroscopy

Lyu

Liu

et al. 2021

Phys. Scr.

View full text Add to dashboard Cite

show abstract

“…LIBS has been successfully applied for ex situ and in situ first wall composition analysis of various tokamaks e.g., JET, ASDEX Upgrade, TEXTOR, EAST, KSTAR, Compass and FTU [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. It was demonstrated that the method is able to determine the depth distribution of the main constituents of the plasma facing components (PFC) and sometimes also the trace elements [14,17,18].…”

Section: Introductionmentioning

confidence: 99%

Ex Situ LIBS Analysis of WEST Divertor Wall Tiles after C3 Campaign

Jõgi

Paris²,

Bernard³

et al. 2023

JNE

View full text Add to dashboard Cite

Fuel retention monitoring in tokamak walls requires the development of remote composition analysis methods such as laser-induced breakdown spectroscopy (LIBS). The present study investigates the feasibility of the LIBS method to analyse the composition and fuel retention in three samples from WEST divertor erosion marker tiles after the experimental campaign C3. The investigated samples originated from tile regions outside of strong erosion and deposition regions, where the variation of thin deposit layers is relatively small and facilitates cross-comparison between different analysis methods. The depth profiles of main constituents W, Mo and C were consistent with depth profiles determined by other composition analysis methods, such as glow-discharge optical emission spectroscopy (GDOES) and secondary ion mass spectrometry (SIMS). The average LIBS depth resolution determined from depth profiles was 100 nm/shot. The averaging of the spectra collected from multiple spots of a same sample allowed us to improve the signal-to-noise ratio, investigate the presence of fuel D and trace impurities such as O and B. In the investigated tile regions with negligible erosion and deposition, these impurities were clearly detectable during the first laser shot, while the signal decreased to noise level after a few subsequent laser shots at the same spot. LIBS investigation of samples originating from the deposition regions of tiles may further clarify LIBS’ ability to investigate trace impurities.

show abstract

“…The technique is efficient for monitoring a reactor wall but has a problem of scaling on big surfaces about of 1 m 2 . In [16], a laser-induced breakdown spectroscopy (LIBS) technique was applied to measure a thickness of Li film deposited on a wall of the EAST device [17]. A laser shot to the wall was covered by Li during the experiment.…”

Section: Introductionmentioning

confidence: 99%

Analysis of non-ionized substance losses in experiments on plasma mass separation

Usmanov¹,

Antonov²,

Gavrikov³

et al. 2022

Plasma Sci. Technol.

View full text Add to dashboard Cite

Plasma mass separation requires a lot of diagnostic techniques that not only demonstrate the separation effect but also show the efficiency of the process. During the test experiments plasma flux to be separated may contain neutral particles that avoid the separation process due to their insensitivity to electromagnetic field. We present the diagnostics of the lost substance that way in experiments on plasma mass separation. Obtained data of the diagnostics helped to determine the law of particle evaporation from the plasma source. We showed that neutral flux is unable to distort the result of separation diagnostics. Presented approach can be used in experiments aimed at enhancing the separation effect and at achieving target productivity for industry applications.

show abstract

In situ diagnosis of Li-wall conditioning and H/D co-deposition on the first wall of EAST using laser-induced breakdown spectroscopy

Cited by 17 publications

References 15 publications

Characterization on deuterium retention in tungsten target using spatially resolved laser induced desorption-quadrupole mass spectroscopy

Characterization on deuterium retention in tungsten target using spatially resolved laser induced desorption-quadrupole mass spectroscopy

Ex Situ LIBS Analysis of WEST Divertor Wall Tiles after C3 Campaign

Analysis of non-ionized substance losses in experiments on plasma mass separation

Contact Info

Product

Resources

About