Investigation of boron distribution and material migration on the W7-X divertor by picosecond LIBS

2022 ◽  
Author(s):  
Dongye Zhao ◽  
Sebastijan Brezinsek ◽  
Rongxing Yi ◽  
Jannis Oelmann ◽  
Cai Laizhong ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Picosecond Laser ◽  
Depth Resolution ◽  
Deposition Pattern ◽  
Breakdown Spectroscopy ◽  
Fine Grain ◽  
Material Migration ◽  
Laser Induced Breakdown ◽  
Material Erosion

Abstract One set of horizontal target elements of the Test Divertor Units (TDU), retrieved from the Wendelstein 7-X (W7-X) vessel after the end of second divertor Operation Phase (OP1.2B) in Hydrogen (H), were investigated by picosecond Laser-Induced Breakdown Spectroscopy (ps-LIBS). The Boron (B) distribution, H pattern and the material erosion/deposition pattern on these target elements were analyzed with high depth resolution and mapped in the poloidal direction of W7-X. From the spectroscopic analysis, B, H, Carbon (C) and Molybdenum (Mo) were clearly identified. A non-uniformly distributed B pattern on these divertor target elements was determined by the combination of B layer deposition during the three boronizations and W7-X plasma operation with multiple erosion and deposition steps of B. Like the TDU, the analyzed target elements are made of fine grain graphite, but have two marker layers which allow us to determine the material migration via the ps-LIBS technique. Two net erosion zones including one main erosion zone with a peak erosion depth of 6.5 μm and one weak erosion with a peak erosion of 1.3 μm were determined. Between two net erosion zones, a net deposition zone with width of 135 mm and a thickness up to 3.5 μm at the peak deposition location was determined by the ps-LIBS technique. The B distributions are correlated with the erosion/deposition pattern and the operational time in standard magnetic configuration of W7-X in the phases after the boronizations. The thickness of the containing B layer on these target elements also correlates with the erosion/deposition depth, in which the thickness of the containing B layer varies spatially in poloidal direction between 0.1 μm and 6 μm. Complementary, Focused Ion Beam combined with Scanning Electron Microscopy (FIB-SEM) was employed also to verify and investigate the deposition layer thicknesses at typical net erosion and net deposition zones as well as to identify the three boronizations in depth.

Comparison of Focused Ion Beam and Conventional Techniques on Tem Specimen Preparation of Metal-Ceramic Interfaces

1998 ◽  
Vol 4 (S2) ◽  
pp. 860-861 ◽  
Author(s):  
A. Ramirez de Arellano López ◽  
W.-A. Chiou ◽  
K. T. Faber
Keyword(s):  
Focused Ion Beam ◽  
Ceramic Coating ◽  
Steel Substrate ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Inhomogeneous Materials ◽  
Cross Sectional ◽  
Fine Grain ◽  
Basic Industry ◽  
Coated Surface

The results of TEM analyses of materials are critically dependent on the quality of the sample prepared. Although numerous techniques have been developed in the last two decades, differential thinning of inhomogeneous materials remains a serious problem. Recently, focused ion beam (FIB) technique has been introduced for cross-sectional sample preparation for TEM and SEM.A novel system for depositing a fine-grain (∼ 200 nm) ceramic coating on a metal surface via a patent pending Small-Particle Plasma Spray (SPPS) technique has been developed at the Basic Industry Research Laboratory of Northwestern University. To understand the properties of the coated surface, the ceramic/metal interface and the microstructure of the ceramic coating must be investigated. This paper presents a comparison of the microstructure of an A12O3 coating on a mild steel substrate prepared using conventional and FEB techniques.

Highly depth-resolved characterization of fusion-related tungsten material based on picosecond laser-induced breakdown spectroscopy

2020 ◽  
Vol 35 (12) ◽  
pp. 2867-2879
Author(s):  
Dongye Zhao ◽  
Ding Wu ◽  
Jannis Oelmann ◽  
Sebastijan Brezinsek ◽  
Qingmei Xiao ◽  
...  
Keyword(s):  
Nuclear Fusion ◽  
Picosecond Laser ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Potential Applications ◽  
Tungsten Material

The objective of the present study has been to evaluate the potential applications of picosecond laser-induced breakdown spectroscopy (ps-LIBS) in nuclear fusion devices.

scholarly journals Application of picosecond laser-induced breakdown spectroscopy to quantitative analysis of boron in meatballs and other biological samples

2016 ◽  
Vol 55 (32) ◽  
pp. 8986 ◽  
Author(s):  
Rinda Hedwig ◽  
Kurnia Lahna ◽  
Zener Sukra Lie ◽  
Marincan Pardede ◽  
Koo Hendrik Kurniawan ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Biological Samples ◽  
Picosecond Laser ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

scholarly journals Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 853 ◽  
Author(s):  
Marco Sebastiani ◽  
Edoardo Rossi ◽  
Muhammad Zeeshan Mughal ◽  
Alessandro Benedetto ◽  
Paul Jacquet ◽  
...  
Keyword(s):  
Residual Stress ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Depth Profiling ◽  
Strain Analysis ◽  
Depth Resolution ◽  
Image Correlation ◽  
Nano Scale ◽  
Unique Method ◽  
The Individual

Silver-based low-emissivity (low-E) coatings are applied on architectural glazing to cost-effectively reduce heat losses, as they generally consist of dielectric/Ag/dielectric multilayer stacks, where the thin Ag layer reflects long- wavelength infrared (IR), while the dielectric layers both protect the Ag and act as an anti-reflective barrier. The architecture of the multilayer stack influences its mechanical properties and it is strongly dependent on the residual stress distribution in the stack. Residual stress evaluation by combining focused ion beam (FIB) milling and digital image correlation (DIC), using the micro-ring core configuration (FIB-DIC), offers micron-scale lateral resolution and provides information about the residual stress variation with depth, i.e., it allows depth profiling for both equibiaxial and non-equibiaxial stress distributions and hence can be effectively used to characterize low-E coatings. In this work, we propose an innovative approach to improve the depth resolution and surface sensitivity for residual stress depth profiling in the case of ultra-thin as-deposited and post-deposition annealed Si3N4/Ag/ZnO low-E coatings, by considering different fractions of area for DIC strain analysis and accordingly developing a unique influence function to maintain the sensitivity of the technique at is maximum during the calculation. Residual stress measurements performed using this novel FIB-DIC approach revealed that the individual Si3N4/ZnO layers in the multilayer stack are under different amounts of compressive stresses. The magnitude and orientation of these stresses changes significantly after heat treatment and provides a clear explanation for the observed differences in terms of scratch critical load. The results show that the proposed FIB-DIC combined-areas approach is a unique method for accurately probing non-equibiaxial residual stresses with nano-scale resolution in thin films, including multilayers.

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