Experimental studies of the interactions between a hydrogen plasma and a carbon or tungsten wall

Ouaras, Karim; Delacqua, L. Colina; Quirós, C.; Lombardi, G.; Rédolfi, M.; Vrel, D.; Hassouni, K.; Bonnin, X.

doi:10.1088/1742-6596/591/1/012029

Cited by 4 publications

(4 citation statements)

References 6 publications

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“…An aspect of fundamental importance is the interaction between W and plasma, which has been investigated either in fusion devices such as TEXTOR [20], ASDEX-U [21], and PF-1000 facility [22] or through laboratory simulations [23][24][25][26][27][28][29][30][31][32]. Particular attention has been paid to steady thermal loads, while some studies have focused on transient high heat loads, which may induce serious damage and degradation of W.…”

Section: Introductionmentioning

confidence: 99%

Laser Pulse Effects on Plasma-Sprayed and Bulk Tungsten

Montanari

Pakhomova

Pizzoferrato

et al. 2017

Metals

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Tungsten (W) is considered a promising plasma-facing material for protecting the divertor of the ITER (International Thermonuclear Experimental Reactor). The effects on W of transient thermal loads of high energy occurring in a tokamak under operative conditions have been simulated through a single laser pulse delivered by an Nd:YAG laser. Bulk and plasma-sprayed (PS) samples have been submitted to tests and successively examined via SEM (scanning electron microscopy) observations. In both types of materials, the laser pulse induces similar effects: (i) a crater forms in the spot central area; (ii) all around the area, the ejection and the movement of molten metal give rise to a ridge; (iii) in a more external area, the surface shows plates with jagged boundaries and cracks induced by thermal stresses; (iv) the pores present in the original material become preferred ablation sites. However, the affected surface area in PS samples is larger and asymmetric if compared to that of bulk material. Such a difference has been explained by considering how microstructural characteristics influence heat propagation from the irradiated spot, and it was found that grain size and shape play a decisive role.

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Section: Introductionmentioning

confidence: 99%

Laser Pulse Effects on Plasma-Sprayed and Bulk Tungsten

Montanari

Pakhomova

Pizzoferrato

et al. 2017

Metals

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“…Extensive research campaigns aimed at studying the PFM interaction with the plasma have been held by different facilities [36][37][38] and by many laboratory experiments [39][40][41][42][43][44][45][46][47][48]. In such context, it is worth to recall the occurrence of the melting failure event during the plasma campaign in 2019 on the EAST tokamak [49][50][51][52].…”

Section: Overview Of the Issuementioning

confidence: 99%

New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing

2023

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The construction and operation of the first generation of magnetically controlled nuclear fusion power plants require the development of proper physics and the engineering bases. The analysis of data, recently collected by the actual largest and most important tokamak in the world JET, that has successfully completed his second deuterium and tritium campaign in 2021 (DTE2) with a full ITER like wall main chamber, has provided an important consolidation of the ITER physics basis. Thermonuclear plasmas are highly nonlinear systems characterized by the need of numerous diagnostics to measure physical quantities to guide, through proper control schemes, external actuators. Both modelling and machine learning approaches are required to maximize the physical understanding of plasma dynamics and at the same time, engineering challenges have to be faced. Fusion experiments are indeed extremely hostile environments for plasma facing materials (PFM) and plasma-facing components (PFC), both in terms of neutron, thermal loads and mechanical stresses that the components have to face during either steady operation or off-normal events. Efforts are therefore spent by the community to reach the ultimate goal ahead: turning on the first nuclear fusion power plant, DEMO, by 2050. This editorial is dedicated at reviewing some aspects touched in recent studies developed in this dynamic, challenging project, collected by the special issue titled “New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing”.

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“…[8][9][10][11] Such laboratory "PSI simulators" have already been used for carbon and tungsten material studies. [4][5][6]8,9,12 Several research groups attempted to develop and characterize large area and/or volume microwave sources, [13][14][15][16][17] many of which made use of electron cyclotron resonance (ECR) coupling. Ono et al 13 investigated high density large area argon plasmas, i.e., up to 10 13 cm À3 density and 45 cm diameter, generated in plane-slotted antennas with permanent magnets.…”

Section: Introductionmentioning

confidence: 99%

Qualification of uniform large area multidipolar ECR hydrogen plasma

Colina-Delacqua¹,

Rédolfi²,

Ouaras

et al. 2022

Physics of Plasmas

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The design and characterization of a multi-dipolar microwave electron cyclotron resonance (ECR) hydrogen plasma reactor are presented. In this configuration, 16 ECR sources are disposed uniformly along the azimuthal direction at a constant distance from the center of a cylindrical reactor. Several plasma diagnostics have been used to determine key parameters such as neutral species temperature; electron density and temperature; and H+, H2+, and H3+ ion energy distributions. The experimental characterization is supported by electromagnetic and magnetostatic field simulations as well as Particle In-Cell Monte Carlo Collisions simulations to analyze the observed ion energy distribution functions. Especially, we show that both electron density and temperature are spatially uniform, i.e., 1011 cm−3 and 3 eV, respectively. This plasma enables generating ion flux and energy in the ranges 1019–1022 ions m−2 s−1 and few keVs, respectively. The H2+ ion distribution function shows two populations which were attributed to surface effects. These features make this reactor particularly suitable for studying hydrogen plasma surface interaction under controlled conditions.

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Experimental studies of the interactions between a hydrogen plasma and a carbon or tungsten wall

Cited by 4 publications

References 6 publications

Laser Pulse Effects on Plasma-Sprayed and Bulk Tungsten

Laser Pulse Effects on Plasma-Sprayed and Bulk Tungsten

New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing

Qualification of uniform large area multidipolar ECR hydrogen plasma

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