Development of plasma cleaning techniques for in-vessel optical components in ITER

Arkhipov, Ievgen I.; Gorodetsky, А.Е.; Залавутдинов, Р. Х.; Bukhovets, V. L.; Захаров, А.П.; Mukhin, E. E.; Razdobarin, A. G.; Семенов, В. В.; Vukolov, K.Yu.; Mukhammedzyanov, T.R.; Gott, Y.-U.; Taranchenko, A.; Zvonkov, S.N.

doi:10.1016/j.jnucmat.2010.09.038

Cited by 15 publications

(16 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…5a) is due to the imperfection of upper interface of oxide film and should be neglected. According to [10], the current density as low as 0.1 mA/cm 2 on the mirror surface and the accelerating voltage of 50 V are sufficient to provide effective cleaning the first mirror of the divertor TS diagnostics system from a-C:H deposits. As follows from Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The mirrors of this type combine high stability of optical characteristics under deposition-dominated conditions and resistance to the mechanical and thermal stresses. The experimental results on sputtering of ZrO 2 protective film with deuterium ion flux appear to be promising: ZrO 2 film on the surface of the first mirror of the divertor TS system was shown to lose less than 10% of the total thickness during the entire period of ITER operation in the case it is subjected to cleaning discharge with the parameters given in [10]. As was shown earlier [6], the ZrO 2 also provides a good protection from deuterium in-diffusion, thus preventing blisters on the mirror surface.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Diagnostic mirrors with transparent protection layer for ITER

Razdobarin

Mukhin

Семенов

et al. 2011

Fusion Engineering and Design

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Diagnostic mirrors with transparent protection layer for ITER

Razdobarin

Mukhin

Семенов

et al. 2011

Fusion Engineering and Design

View full text Add to dashboard Cite

“…A similar procedure with exploitation of a low temperature ECR plasma was successfully used to remove a carbon layer that appeared during exposition of mirrors in the LHD heliotron [66], the TRIAM-1 tokamak [67], in the test stand DSM-2, and similarly, of mirrors exposed in DIII-D and TEXTOR in the toroidal stand TOMAS [68]. A high efficiency of chemical cleaning of hydrocarbon films was demonstrated in ref [69].…”

Section: Removal Of Deposited Filmmentioning

confidence: 99%

Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

Voitsenya¹,

Bardamid²,

Donné³

2016

PHY

View full text Add to dashboard Cite

In the experimental fusion reactor ITER, the plasma-facing component of each optical and/or laser diagnostic needs to be based on reflective optics with at least one mirror (first mirror) facing the thermonuclear plasma. The different kinds of radiation emanating from the burning plasma (neutrons, neutral atoms, electromagnetic radiation) create hostile operating conditions for the first mirrors. Therefore, a special program has been set up under the ITER framework aimed at solving the first mirror problem. This paper will review the main results in this field that have been obtained in the Institute of Plasma Physics, National Science Center “Kharkov Institute of Physics and Technology” (in many cases in cooperation with groups of other countries, as indicated in corresponding parts of the manuscript) during long-term investigations directed to find a solution of this problem,i.e., to find a material and accompanying precautions in order to satisfy the requirements for first mirrors. The main efforts were devoted to finding solutions to overcome the impact of the most severe deteriorating factors resulting in degradation of the optical properties of mirrors: sputtering by charge exchange atoms and deposition of contaminants. The obtained results are focused on: the effects of long term sputtering on mirror specimens fabricated from different metals with different structures (polycrystals, single crystals, metal film on metal substrates, amorphous), the effects of contaminating film and the possible protection to avoid of its appearance, the role of chemical processes for some metal mirrors, and the choice of material of laser mirrors.

show abstract

“…TEXTOR did not experience any long term adverse consequences after the use of oxygen to remove deuterium, and high performance plasma operation was recovered shortly after the treatment. 3 In-vessel components of International Thermonuclear Experimental Reactor (ITER) 4,5 are subject to plasmainduced erosion and subsequent deposition of eroded material, which has to be removed during maintenance. An out-of-vessel technique was proposed to clean the elements, whereby a contaminated component is dismounted from the vessel and placed in an auxiliary cleaning reactor, where a d.c. glow discharge was applied.…”

Section: Introductionmentioning

confidence: 99%

“…An out-of-vessel technique was proposed to clean the elements, whereby a contaminated component is dismounted from the vessel and placed in an auxiliary cleaning reactor, where a d.c. glow discharge was applied. 4 Ongoing research has been active on treatment of walls of a plasma reactor. 6 Dylla 7 has acknowledged the beneficial role of glow discharge conditioning as in situ procedure and proposed this application to magnetic fusion devices and to particle accelerator systems.…”

Section: Introductionmentioning

confidence: 99%

Resonant-frequency discharge in a multi-cell radio frequency cavity

Popović

Upadhyay

Mammosser

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

We are reporting experimental results on a microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency cryo-module. This discharge offers a mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the issues related to resonant detuning due to sustained multi-cell cavity plasma. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal. V

show abstract

Development of plasma cleaning techniques for in-vessel optical components in ITER

Cited by 15 publications

References 10 publications

Diagnostic mirrors with transparent protection layer for ITER

Diagnostic mirrors with transparent protection layer for ITER

Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

Resonant-frequency discharge in a multi-cell radio frequency cavity

Contact Info

Product

Resources

About