Nuclear Materials and Energy最新文献

{"title":"Effect of yttrium addition on structural, mechanical and thermodynamic properties of tungsten-yttrium alloys","authors":"Sabahattin Akbas ,&nbsp;Mustafa Kemal Ozturk ,&nbsp;Fatih Aydogan","doi":"10.1016/j.nme.2024.101860","DOIUrl":"10.1016/j.nme.2024.101860","url":null,"abstract":"<div><div>Based on the supercell structures of bcc-W, the effect of yttrium on the structural, mechanical, and thermodynamic properties of tungsten-yttrium alloys is investigated using first-principles calculations. In this study, five new models of tungsten-yttrium alloys are constructed, namely W₁₅Y₁, W₁₄Y₂, W₁₂Y₄, W₁₀Y₆, and W₈Y₈. The obtained values of elastic constants and mechanical criteria show that these alloys are mechanically stable. The mechanical parameters, including elastic moduli (bulk modulus, shear modulus, and Young’s modulus), Poisson’s ratio, B/G ratio, Cauchy pressure, and Vickers hardness, indicate a decrease of the mechanical properties compared to pure tungsten, though significant improvements in plasticity and ductility are observed. According to the phonon spectrum, the calculated thermodynamic parameters, such as heat capacity, entropy, and enthalpy of the alloys increase with increasing yttrium content and temperature compared to those of pure tungsten. Despite a decrease in Debye temperature, thermal conductivity and melting point with rising yttrium content, the thermal expansion coefficient shows an increasing trend. These findings provide valuable insights into the potential of tungsten-yttrium alloys for advanced applications, particularly in the context of fusion materials.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101860"},"PeriodicalIF":2.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation of the impact of irradiation damages on the mechanical properties of tungsten","authors":"Robert Lürbke ,&nbsp;J. Riesch ,&nbsp;A. Feichtmayer ,&nbsp;B. Curzadd ,&nbsp;T. Höschen ,&nbsp;R. Neu","doi":"10.1016/j.nme.2024.101858","DOIUrl":"10.1016/j.nme.2024.101858","url":null,"abstract":"<div><div>Tungsten (W) is considered the preferred plasma-facing material (PFM) in future magnetic confinement fusion reactors. There it will be exposed to high heat fluxes and intense neutron radiation. Neutron irradiation could have an embrittling effect on is expected to cause irradiation hardening and embrittling of the material, which poses a significant threat for the structural integrity of tungsten components. High-energy self-ion irradiation can be used to simulate the displacement damage caused by neutrons irradiation in tungsten. Due to the low penetration depth of heavy ion radiation in W, thin W wires are used as a model system since they can be irradiated throughout their full entire volume. The very fine microstructure of such wires allows size effects to be reduced. To measure the effect of heavy self-ion irradiation, 16 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span> diameter W wires were thinned to 5 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span> and then irradiated with 20.3 MeV <span><math><msup><mrow><mi>W</mi></mrow><mrow><mn>6</mn><mo>+</mo></mrow></msup></math></span> ions. Mechanical properties were determined by tensile testing and scanning electron microscopy (SEM) imaging of the area reduction as a measurement for ductility. Ten wires each were irradiated at 0.2 dpa, 1 dpa, and 10 dpa and compared with the as-received material. In the as-fabricated state, these wires show a pronounced ductile behavior. The irradiation damage did not alter the mechanical properties or the area reduction of the samples.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101858"},"PeriodicalIF":2.3,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma-wall interaction impact of the ITER re-baseline","authors":"R.A. Pitts ,&nbsp;A. Loarte ,&nbsp;T. Wauters ,&nbsp;M. Dubrov ,&nbsp;Y. Gribov ,&nbsp;F. Köchl ,&nbsp;A. Pshenov ,&nbsp;Y. Zhang ,&nbsp;J. Artola ,&nbsp;X. Bonnin ,&nbsp;L. Chen ,&nbsp;M. Lehnen ,&nbsp;K. Schmid ,&nbsp;R. Ding ,&nbsp;H. Frerichs ,&nbsp;R. Futtersack ,&nbsp;X. Gong ,&nbsp;G. Hagelaar ,&nbsp;E. Hodille ,&nbsp;J. Hobirk ,&nbsp;W. Zhang","doi":"10.1016/j.nme.2024.101854","DOIUrl":"10.1016/j.nme.2024.101854","url":null,"abstract":"&lt;div&gt;&lt;div&gt;To mitigate the impact of technical delays, provide a more rationalized approach to the safety demonstration and move forward as rapidly as possible to a reactor relevant materials choice, the ITER Organization embarked in 2023 on a significant re-baselining exercise. Central to this strategy is the elimination of beryllium (Be) first wall (FW) armour in favour of tungsten (W), placing plasma-wall interaction (PWI) centre stage of this new proposal. The switch to W comes with a modified Research Plan in which a first “Start of Research Operation” (SRO) campaign will use an inertially cooled, temporary FW, allowing experience to be gained with disruption mitigation without risking damage to the complex water-cooled panels to be installed for later DT operation. Conservative assessments of the W wall source, coupled with integrated modelling of W pedestal and core transport, demonstrate that the elimination of Be presents only a low risk to the achievement of the principal ITER Q = 10 DT burning plasma target. Primarily to reduce oxygen contamination in the limiter start-up phase, known to be a potential issue for current ramp-up on W surfaces, a conventional diborane-based glow discharge boronization system is included in the re-baseline. First-of-a-kind modelling of the boronization glow is used to provide the physics specification for this system. Erosion simulations accounting for the 3D wall geometry provide estimates both of the lifetime of boron (B) wall coatings and the subsequent B migration to remote areas, providing support to a simple evaluation which concludes that boronization, if it were to be used frequently, would dominate fuel retention in an all-W ITER. Boundary plasma (SOLPS-ITER) and integrated core–edge (JINTRAC) simulations, including W erosion and transport, clearly indicate the tendency for a self-regulating W sputter source in limiter configurations and highlight the importance of on-axis electron cyclotron power deposition to prevent W core accumulation in the early current ramp phase. These predicted trends are found experimentally in dedicated W limiter start-up experiments on the EAST tokamak. The SOLPS-ITER runs are used to formulate W source boundary conditions for 1.5D DINA code scenario design simulations which demonstrate that flattop durations of ∼100 s should be possible in hydrogen L-modes at nominal field and current (I&lt;sub&gt;p&lt;/sub&gt; = 15 MA, B&lt;sub&gt;T&lt;/sub&gt; = 5.3 T) which are one of the principal SRO targets. Runaway electrons (RE) are considered to be a key threat to the integrity of the final, actively cooled FW panels. New simulations of RE deposition and subsequent thermal transport in W under conservative assumptions for the impact energy and spatial distribution, conclude that there is a strong argument to increase the W armour thickness in key FW areas to improve margins against cooling channel interface damage in the early DT operation phases when new RE seeds will be experienced for the first t","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101854"},"PeriodicalIF":2.3,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle control via cryopumping and its impact on the edge plasma profiles of Alcator C-Mod","authors":"M.A. Miller ,&nbsp;J.W. Hughes ,&nbsp;S. Mordijck ,&nbsp;M. Wigram ,&nbsp;J. Dunsmore ,&nbsp;R. Reksoatmodjo ,&nbsp;R.S. Wilcox","doi":"10.1016/j.nme.2024.101856","DOIUrl":"10.1016/j.nme.2024.101856","url":null,"abstract":"&lt;div&gt;&lt;div&gt;At the high &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; proposed for high-field fusion reactors, it is uncertain whether ionization, as opposed to plasma transport, will be most influential in determining &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; at the pedestal and separatrix. A database of Alcator C-Mod discharges is analyzed to evaluate the impact of source modification via cryopumping. The database contains similarly-shaped H-modes at fixed &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; MA and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; T, spanning a large range in &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;net&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and ionization. Measurements from an edge Thomson scattering system are combined with those from a midplane-viewing Ly&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; camera to evaluate changes to &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; in response to changes to ionization rates, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;ion&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;. &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;sep&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;ped&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; are found to be most sensitive to changes to &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;ion&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;sep&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;, as opposed to &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;ped&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;sep&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;. Dimensionless quantities, namely &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;MHD&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;ν&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, are found to regulate attainable pedestal values. Select discharges at different values of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;net&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and in different pumping configurations are analyzed further using SOLPS-ITER. It is determined that changes to plasma transport coefficients are required to self-consistently model both plasma and neutral edge dynamics. Pumping is found to modify the poloidal distribution of atomic neutral density, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, along the separatrix, increasing &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101856"},"PeriodicalIF":2.3,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deuterium retention behaviors of boronization films at DIII-D divertor surface","authors":"Shota Abe ,&nbsp;Michael J. Simmonds ,&nbsp;Alessandro Bortolon ,&nbsp;Florian Effenberg ,&nbsp;Igor Bykov ,&nbsp;Jun Ren ,&nbsp;Dmitry L. Rudakov ,&nbsp;Ryan Hood ,&nbsp;Alan W. Hyatt ,&nbsp;Zihan Lin ,&nbsp;Tyler Abrams","doi":"10.1016/j.nme.2024.101855","DOIUrl":"10.1016/j.nme.2024.101855","url":null,"abstract":"<div><div>Boron coating of plasma-facing components (PFCs) is widely used in fusion devices to form surface coatings and chemical compounds on the PFCs, thus suppressing plasma contamination by impurities such as oxygen, carbon, and tungsten. Understanding the processes of hydrogenic species retention is crucial to assessing the viability of boron coating techniques in ITER and beyond. In this work, we deposited boronization films on silicon crystal and ITER-grade tungsten samples using a glow discharge boronization plasma of helium (He, 85 %) and diborane (B₂D₆, 15 %) in the DIII-D tokamak at the heated vessel temperature of 600 K. We performed post-mortem analysis of DIII-D boronization films for thickness utilizing a focused ion beam, deuterium retention utilizing thermal desorption spectroscopy (TDS), and chemical characterization utilizing X-ray photoelectron spectroscopy and Raman spectroscopy. The DIII-D boronization films were exposed to DIII-D tokamak L-, H-mode, and/or PISCES-E linear device D plasmas. We observed a D uptake for B:D = 5:2 in the DIII-D boronization film before D plasma exposures. The observed D retention was mainly in the B<img>C<img>D bond with a desorption peak of 1000 K. No B-D bond with a desorption peak around 700 K was found in the TDS spectrum as the DIII-D vessel was heated to 600 K. Exposures to both DIII-D L- and H-mode D plasma, which includes 1–3 % of C ion contamination, on the DIII-D boronization film at ∼400 K gave a D uptake increase of ∼20 %. Contrarily, D removal by ∼30 % was observed after exposing the DIII-D boronization film to a carbon-free PISCES-E D plasma. This implies that future fusion devices should be careful to minimize C impurity contamination to reduce D retention.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101855"},"PeriodicalIF":2.3,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SOLPS-ITER modification for impurity transport modelling in the tokamak pedestal region","authors":"V. Korzueva ,&nbsp;E. Kaveeva ,&nbsp;V. Rozhansky ,&nbsp;X. Bonnin","doi":"10.1016/j.nme.2024.101847","DOIUrl":"10.1016/j.nme.2024.101847","url":null,"abstract":"<div><div>Kinetic corrections to SOLPS-ITER fluid equations are made to extend their applicability for description of the neoclassical part of impurity transport to collisionless regimes of the main ions. Analysis is performed of impurity transport for the H-mode transport edge barrier and pedestal for several tokamaks: ASDEX-Upgrade, JET and ITER based on SOLPS-ITER modelling. Poloidal distribution of impurities and their radial fluxes are studied in detail. Significant difference of impurity drift flows with respect to neoclassical theory predictions is obtained for JET and ASDEX-Upgrade, while for ITER the drift flows reproduce neoclassical transport.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101847"},"PeriodicalIF":2.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of high-field side plasma instabilities in tokamak edge","authors":"M.V. Umansky","doi":"10.1016/j.nme.2024.101820","DOIUrl":"10.1016/j.nme.2024.101820","url":null,"abstract":"<div><div>Balanced double-null configurations are of general interest for boundary plasma physics, and they have been proposed for some future designs. Experimental observations demonstrate absence of plasma fluctuations in tokamak high-field side scrape-off layer in a balanced double-null configuration (Smick et al., 2013), and it is commonly assumed that plasma instabilities are suppressed on high-field side in the edge plasma due to the stabilizing effect of magnetic curvature. At the same time, the experimental evidence points to extremely steep plasma density profiles on high-field side, which should provide a strong instability drive. In the present study, the drift-resistive-ballooning mode instability model is investigated analytically and numerically to determine the characteristics of plasma instabilities, turbulence, and transport in tokamak scrape-off layer on high-field side.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101820"},"PeriodicalIF":2.3,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dust collection after the high fluence campaign of the WEST tokamak","authors":"C. Arnas ,&nbsp;A. Campos ,&nbsp;M. Diez ,&nbsp;E. Bernard ,&nbsp;C. Brun ,&nbsp;C. Martin ,&nbsp;F. Gensdarmes ,&nbsp;S. Peillon ,&nbsp;E. Tsitrone ,&nbsp;the WEST team","doi":"10.1016/j.nme.2024.101848","DOIUrl":"10.1016/j.nme.2024.101848","url":null,"abstract":"<div><div>For Phase 2 of WEST, the lower divertor was entirely equipped with actively cooled ITER grade plasma-facing units made of chains of tungsten beveled monoblocks. In this configuration, dust particles were collected in 2023, after the first plasma campaign mainly dedicated to repetitive long pulses in the conditions of attached plasmas to the divertor. Due to a high particle fluence and a significant tungsten erosion, large quantities of dust were produced. In addition to those produced during off-normal events and the flaking of deposits which are typical of tokamak wall erosion, dust particles due to the flaking of pure tungsten thin layers deposited on the shadowed areas of beveled monoblocks were found. As specific characteristic, these thin layers may not adhere to the divertor and consequently, may be peeled off and mobilized during plasma operation.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101848"},"PeriodicalIF":2.3,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the 2H(3He, p0)4He nuclear reaction for deuterium depth profiling","authors":"Varvara Foteinou ,&nbsp;Fotios Maragkos ,&nbsp;Hans-Werner Becker ,&nbsp;Michael Kokkoris ,&nbsp;Matej Mayer ,&nbsp;Georgios Provatas ,&nbsp;Detlef Rogalla ,&nbsp;Thomas Schwarz-Selinger","doi":"10.1016/j.nme.2024.101853","DOIUrl":"10.1016/j.nme.2024.101853","url":null,"abstract":"<div><div>The differential cross sections of the ²H(³He,<!--> <!-->p₀)⁴He reaction have been determined at six detection angles (120°, 130°, 140°, 150°, 160° and 170°) in the energy range between 300 and 4000 <!--> <!-->keV, with steps of 30 to 100<!--> <!-->keV. The measurements were performed at the 4<!--> <!-->MV Dynamitron Tandem Laboratory of the Central Unit for Ion Beams and Radionuclides of the Ruhr University Bochum in Germany. A thin layer of amorphous deuterated hydrocarbon (a-C:D) plasma-deposited on a chromium substrate was used in all measurements. Overall, the results of the present study are in very good agreement with differential cross-section data available in the literature for similar detection angles, with an average deviation of less than 6 %.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101853"},"PeriodicalIF":2.3,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wall conditions on HL-2A and HL-3 tokamaks","authors":"Chengzhi Cao,&nbsp;Xiangmei Huang,&nbsp;Yi Hu,&nbsp;Yanfeng Xie,&nbsp;Jun Zhou,&nbsp;Tao Qiao,&nbsp;Jinming Gao,&nbsp;Laizhong Cai,&nbsp;Zeng Cao,&nbsp;HL-2A and HL-3 team","doi":"10.1016/j.nme.2024.101852","DOIUrl":"10.1016/j.nme.2024.101852","url":null,"abstract":"<div><div>This paper presents the wall conditioning of HL-2A and HL-3 tokamaks. It details the enhancement of plasma performance achieved through siliconization processes on the HL-2A tokamak, encompassing both offline and in-situ methodologies. A study on the impact of offline siliconization on impurity concentration within HL-2A is presented, and real-time siliconization results demonstrate that it has no effect on plasma discharge. The findings indicate that in-situ siliconization is equally effective as the offline process with regard to plasma performance. With appropriate 13.56 MHz radio frequency (RF) power and pressure, a uniform glow discharge was achieved under 0.1 T in HL-2A. The effectiveness of impurity removal on HL-3 at different baking temperatures has been investigated. Measurements of glow discharge plasma density and temperature reveal that the parameters farthest from the electrode are 6 eV and ∼ 8 × 10¹² m⁻³. Based on the breakdown tests, it was determined that the minimum breakdown voltage is approximate 430 V, and the lowest breakdown pressure is around 2.1 × 10^-2 Pa when using 2.1 MHz RF power. Furthermore, experiments were conducted to investigate the efficiency of radio frequency assisted glow discharge cleaning for impurity removal. The study also evaluated the effectiveness of various methods for removing impurities. Additionally, siliconization on HL-3 was implemented successfully with determination of all key control parameters.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101852"},"PeriodicalIF":2.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}