Journal ArticleDOI
Tungsten dust impact on ITER-like plasma edge
TLDR
In this paper, the impact of tungsten dust originating from divertor plates on the performance of edge plasma in ITER-like discharge is evaluated using computer modeling with the coupled dust-plasma transport code DUSTT-UEDGE.Abstract:
The impact of tungsten dust originating from divertor plates on the performance of edge plasma in ITER-like discharge is evaluated using computer modeling with the coupled dust-plasma transport code DUSTT-UEDGE. Different dust injection parameters, including dust size and mass injection rates, are surveyed. It is found that tungsten dust injection with rates as low as a few mg/s can lead to dangerously high tungsten impurity concentrations in the plasma core. Dust injections with rates of a few tens of mg/s are shown to have a significant effect on edge plasma parameters and dynamics in ITER scale tokamaks. The large impact of certain phenomena, such as dust shielding by an ablation cloud and the thermal force on tungsten ions, on dust/impurity transport in edge plasma and consequently on core tungsten contamination level is demonstrated. It is also found that high-Z impurities provided by dust can induce macroscopic self-sustained plasma oscillations in plasma edge leading to large temporal variations of edge plasma parameters and heat load to divertor target plates.read more
Citations
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Journal ArticleDOI
Physics of ultimate detachment of a tokamak divertor plasma
TL;DR: In this paper, the basic physics of the processes playing the most important role in divertor plasma detachment is reviewed, and the models used in the two-dimensional edge plasma transport codes that are widely used to address different issues of the edge plasma physics and to simulate the experimental data, as well as the numerical schemes and convergence issues, are described.
Journal ArticleDOI
Divertor plasma detachment
TL;DR: In this paper, the authors show that the increase of impurity radiation loss and volumetric plasma recombination causes the rollover of the plasma flux to the target when the density increases, which is the manifestation of detachment.
Journal ArticleDOI
Helium concentration measurement in tungsten fuzz-like nanostructures by means of thermal desorption spectroscopy
TL;DR: In this paper, the concentration of helium in tungsten fuzz-like nanostructures has been measured by means of thermal desorption spectroscopy, and the helium content was measured first in the as-irradiated sample, and then in a similar sample with the fuzz mechanically scraped from the sample surface.
Journal ArticleDOI
Interaction of adhered metallic dust with transient plasma heat loads
Svetlana V. Ratynskaia,Panagiotis Tolias,Igor Bykov,D.L. Rudakov,M. De Angeli,Ladislas Vignitchouk,D. Ripamonti,G. Riva,S. Bardin,H.J. van der Meiden,J.W.M. Vernimmen,K. Bystrov,G. De Temmerman +12 more
TL;DR: In this paper, the first study of the interaction of metallic dust (tungsten, aluminum) adhered on tungsten substrates with transient plasma heat loads is presented, and experiments are carried out in the Pilot-PSI linear device with transient heat fluxes up to 550 MW m −2 and in the DIII-D divertor tokamak.
Journal ArticleDOI
Doping of helium at Fe/W interfaces from first principles calculation
TL;DR: In this paper, it was shown that He atoms in the W lattice should have a tendency to diffuse into the Fe lattice of Fe/W interface, and that He energetically prefers the substitution of W or Fe atom, rather than the interstitial sites.
References
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Journal ArticleDOI
Steady-state radiative cooling rates for low-density, high-temperature plasmas
TL;DR: For 47 elements in the range 2 ≤ Z ≤ 92, steady-state radiative cooling rates, average charge states, and mean square charge states have been calculated for low-density, high-temperature plasmas (n e ≲ 10 16 electrons/cm 3 and T = 0.002-100 keV) as discussed by the authors.
Journal ArticleDOI
Recent analysis of key plasma wall interactions issues for ITER
J. Roth,E. Tsitrone,A. Loarte,Th. Loarer,G.F. Counsell,Rudolf Neu,V. Philipps,S. Brezinsek,Michael Lehnen,P. Coad,Ch. Grisolia,Klaus Schmid,K. Krieger,A. Kallenbach,Bruce Lipschultz,R.P. Doerner,Rion A. Causey,V.K. Alimov,W. M. Shu,O. V. Ogorodnikova,A. Kirschner,Gianfranco Federici,A.S. Kukushkin +22 more
TL;DR: In this paper, different aspects of the PWI are assessed in their importance for the initial wall materials choice: CFC for the strike point tiles, W in the divertor and baffle and Be on the first wall.
Journal ArticleDOI
A full tungsten divertor for ITER: Physics issues and design status
R.A. Pitts,S. Carpentier,Frederic Escourbiac,T. Hirai,V. Komarov,S.W. Lisgo,A.S. Kukushkin,A. Loarte,Mario Merola,A. Sashala Naik,R. Mitteau,Masayoshi Sugihara,B. Bazylev,P.C. Stangeby +13 more
TL;DR: In this article, the authors consider the risks engendered by the baseline divertor strategy with regard to known W plasma-material interaction issues and briefly present the current status of a possible full-tungsten (W) divertor design.
Journal ArticleDOI
Formation of Nanostructured Tungsten with Arborescent Shape due to Helium Plasma Irradiation
TL;DR: Deeply nanostructured tungsten with an arborescent shape was found for the first time to be formed on Tungsten-coated graphite by high-flux helium plasma irradiation at surface temperatures of 1250 and 1600 K, an incident ion energy of 12 eV (well below the physical sputtering threshold) and a helium ion fluence of 3.5 × 1027 m-2 as discussed by the authors.
Journal ArticleDOI
Key ITER plasma edge and plasma–material interaction issues
G. Federici,Philip Andrew,P. Barabaschi,Jeffrey N. Brooks,R.P. Doerner,A. Geier,A. Herrmann,G. Janeschitz,K. Krieger,A. B. Kukushkin,A. Loarte,Rudolf Neu,G. Saibene,Michiya Shimada,G. Strohmayer,Masayoshi Sugihara +15 more
TL;DR: Some of the remaining crucial plasma edge physics and plasma-material interaction issues of the ITER tokamak are discussed in this paper, using either modelling or projections of experimental results from existing TOKAMAK operation or relevant laboratory simulations.