Nuclear Materials and Energy最新文献

{"title":"Effect of Cs atoms adsorption on the work function of the LaB6 (100) surface","authors":"Huaqing Zheng ,&nbsp;Xin Zhang ,&nbsp;Jun Hu ,&nbsp;Yuhong Xu ,&nbsp;Guangjiu Lei ,&nbsp;Sanqiu Liu ,&nbsp;Heng Li ,&nbsp;Zilin Cui ,&nbsp;Yiqin Zhu ,&nbsp;Xiaolong Li ,&nbsp;Xiaoqiao Liu ,&nbsp;Shaofei Geng ,&nbsp;Xiaochang Chen ,&nbsp;Haifeng Liu ,&nbsp;Xianqu Wang ,&nbsp;Hai Liu ,&nbsp;Jun Cheng ,&nbsp;Changjian Tang","doi":"10.1016/j.nme.2025.101863","DOIUrl":"10.1016/j.nme.2025.101863","url":null,"abstract":"<div><div>This study used first-principles density functional theory with cp2k and VASP software to investigate the effects of Cs atoms adsorption on the work function of the LaB₆ (100) surface. The results indicate that the most stable adsorption site for Cs atoms is at the top of the B atoms. The adsorption energy of Cs atoms was decomposed into three parts. The binding energy of the Cs layer on the deformed substrate has the largest contribution to the total adsorption energy and plays a dominant role. Although LaB₆ is considered a potential Cs-free material, we found that Cs atom adsorption further lowers the surface work function compared to a clean LaB₆ (100) model, facilitating electron emission. The change in work function is influenced by the dipole moment and is linearly related to changes in the dipole moment. Additionally, in systems with Cs atom adsorption, the charge rearrangement effect (Δp) dominates changes in the total dipole moment. These results provide some reference for the selection of fusion plasma gird materials and the production of hydrogen negative ion sources for neutral beam injection.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101863"},"PeriodicalIF":2.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173555","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":"Preparation and characterization of marker graphite tiles for PWI research of HL-3","authors":"Jingyang Han ,&nbsp;Yaxiong He ,&nbsp;Dongye Zhao ,&nbsp;Laizhong Cai ,&nbsp;Yiqin Wang ,&nbsp;Wei Qian ,&nbsp;Wenyu Huang ,&nbsp;Yong Lu ,&nbsp;Lijun Cai ,&nbsp;Wulyu Zhong","doi":"10.1016/j.nme.2025.101861","DOIUrl":"10.1016/j.nme.2025.101861","url":null,"abstract":"<div><div>In tokamaks, to understand the erosion and deposition pattern of plasma facing components (PFCs) is crucial for the study of plasma wall interaction (PWI). In this study, a set of dedicated marker graphite tiles consisting of substrate material same as the PFCs of HL-3 tokamak, an interlayer of 0.5 μm Tungsten (W) with width of 50 mm employed as marker, and a 5 μm thick with width of 30 mm carbon (C) marker layer on top, were designed and prepared for the PWI research. The magnetron sputtering technique was employed to make the marker layers including W and C layers. The scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) were used to study the surface morphology, elemental composition and layer structure characterization of marker graphite tiles. The Laser-induced breakdown spectroscopy (LIBS) was employed to perform elemental analysis along the depth direction of the C-W-C structure and W-C structure on the marker graphite tiles. Moreover, during the manufacturing process of marker graphite tiles, glass slides were used to be coated simultaneously with graphite and then measured by profilometer in order to evaluate the thickness of the coating. The cross-section of the marker graphite tiles measured by SEM revealed an average W interlayer thickness of 0.71 μm and an average C layer thickness of 4.75 μm. The LIBS results indicate that the thickness information of the C-W-C structure and the W-C structure is consistent with the findings from SEM analysis. The marker graphite tiles have been installed in HL-3 to perform the PWI studies including the C and W erosion, impurity deposition and material migration via surface element analysis and layer structure analysis of the marker graphite tiles in the next experimental campaign.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101861"},"PeriodicalIF":2.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173489","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":"Effects of poloidal magnetic configurations on expansions of electron cyclotron wall conditioning plasma and hydrogen removal in the integrated commissioning phase of JT-60SA","authors":"M. Fukumoto,&nbsp;T. Nakano,&nbsp;T. Wakatsuki,&nbsp;S. Kojima,&nbsp;Y. Ohtani,&nbsp;R. Sano,&nbsp;S. Inoue,&nbsp;H. Urano,&nbsp;M. Yoshida","doi":"10.1016/j.nme.2024.101816","DOIUrl":"10.1016/j.nme.2024.101816","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Hydrogen (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) molecules were desorbed from the wall by tokamak discharges with helium (He) working gas. Particle balance analysis revealed that up to the same number of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; molecules as the injected He atoms were evacuated per He tokamak discharge. Four sequences of Electron Cyclotron Wall Conditioning with He working gas (He-ECWC) performed after the second series of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; tokamak discharges removed 16% of the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; molecules that had been retained by the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; tokamak discharges. The He-ECWC plasma produced by a fundamental ordinary mode (O1-mode) EC wave with a frequency of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;EC&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 82 GHz expanded along the poloidal magnetic field line. In the He-ECWC plasma produced by the O1-mode EC wave with &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;EC&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 82 GHz, the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; removal ratio relative to the residual &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; molecules was highest with the poloidal magnetic field in a Trapped Particle Configuration (TPC) with an &lt;span&gt;&lt;math&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-index of 0.7 at the toroidal magnetic field of &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;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 1.79 and 2.04 T. A comparable &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; removal ratio was observed with the poloidal magnetic field in a horizontal configuration at &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;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 1.79 T. On a second harmonic extraordinary mode (X2-mode) EC wave with &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;EC&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 110 GHz, the He-ECWC plasma was produced locally. For the He-ECWC with the X2-mode EC wave at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;EC&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 110 GHz, the number of removed &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; molecules did not change significantly between the different poloidal magnetic fields in the TPC at &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;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 1.79 and 2.04 T. No He-ECWC plasma was observed with the poloidal magnetic field in the horizontal magnetic configur","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101816"},"PeriodicalIF":2.3,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173096","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":"Trapping and release of deuterium in helium-induced tungsten fuzz at low temperature","authors":"K. Saito ,&nbsp;D. Hwangbo ,&nbsp;M. Miyamoto ,&nbsp;H. Yoshida ,&nbsp;R. Sasaki ,&nbsp;S. Murakami ,&nbsp;M. Sakamoto","doi":"10.1016/j.nme.2024.101859","DOIUrl":"10.1016/j.nme.2024.101859","url":null,"abstract":"<div><div>The release of deuterium (D) atoms from a nanostructure ‘fuzz’ tungsten (W) after a sequential plasma irradiation of helium (He) and D was explored. Thermal desorption spectroscopy revealed that more than 60% of total D amount was already released at <span><math><mo>&gt;</mo></math></span>423 K. A sophisticated measurement with an aberration-corrected scanning TEM combined with electron energy-loss spectrometer (STEM-EELS) directly showed the trapping of D atoms into He bubbles after the plasma irradiation and the release of D from the He bubbles at elevated temperature at 423 K. The He bubbles containing D were characterized by (i) relatively large volume and (ii) small He energy-loss shift below 2 eV. It is suggested that the shifts in the energy-loss peaks of He and D could be used as indicators of D absorption within He bubbles.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"42 ","pages":"Article 101859"},"PeriodicalIF":2.3,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173093","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":"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}