Pub Date : 2025-12-01Epub Date: 2025-10-22DOI: 10.1016/j.nme.2025.102015
M. Mayer , S. An , T. Bräuer , D. Cipciar , C.P. Dhard , C. Killer , D. Naujoks , V. Rohde , R. Steinwehr , U. von Toussaint , L. Vano , H. Viebke , W7-X Team, ASDEX Upgrade Team
The surface loss probabilities of boron-hydride radicals on silicon surfaces have been measured during boronisations for wall conditioning in the stellarator W7-X and the tokamak ASDEX Upgrade using the cavity technique. The boronisations were performed using a glow-discharge plasma with a mixture of 10 % diborane (B2H6 in W7-X, B2D6 in ASDEX Upgrade) and 90 % Helium at voltages of 300–500 V. Molecular ion species and neutral radicals were distinguished by their incident distributions inside the cavities. In W7-X the incident particles were dominantly ions with 80–95 % contribution to the incident flux, while in ASDEX Upgrade the ion flux contribution was about 65 %. The surface loss probability of the ionic species was about 0.2. One neutral species with surface loss probability close to unity was deduced.
{"title":"Surface loss probabilities of boron-hydride radicals in W7-X and ASDEX Upgrade","authors":"M. Mayer , S. An , T. Bräuer , D. Cipciar , C.P. Dhard , C. Killer , D. Naujoks , V. Rohde , R. Steinwehr , U. von Toussaint , L. Vano , H. Viebke , W7-X Team, ASDEX Upgrade Team","doi":"10.1016/j.nme.2025.102015","DOIUrl":"10.1016/j.nme.2025.102015","url":null,"abstract":"<div><div>The surface loss probabilities of boron-hydride radicals on silicon surfaces have been measured during boronisations for wall conditioning in the stellarator W7-X and the tokamak ASDEX Upgrade using the cavity technique. The boronisations were performed using a glow-discharge plasma with a mixture of 10 % diborane (B<sub>2</sub>H<sub>6</sub> in W7-X, B<sub>2</sub>D<sub>6</sub> in ASDEX Upgrade) and 90 % Helium at voltages of 300–500 <!--> <!-->V. Molecular ion species and neutral radicals were distinguished by their incident distributions inside the cavities. In W7-X the incident particles were dominantly ions with 80–95 % contribution to the incident flux, while in ASDEX Upgrade the ion flux contribution was about 65 %. The surface loss probability of the ionic species was about 0.2. One neutral species with surface loss probability close to unity was deduced.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102015"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145417638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-17DOI: 10.1016/j.nme.2025.102011
Miguel Zavala-Arredondo , Arun Ramanathan Balachandramurthi , Lidija Stjepanic Peric , Nick Weston , Katy Rankin , Sebastian Rosini , Khurram Amjad , Jeong-Ha You
Pure tungsten is one of the promising candidate materials for plasma facing components (PFC) of future fusion reactors due to several favourable properties including its high melting point, high thermal conductivity, high strength, high sputtering resistivity and low coefficient of thermal expansion. Increasing geometric complexity and productivity of tungsten PFC is of interest to improve thermal performance and availability for new tokamaks with a view to future steady state plasma operation. Additive manufacturing (AM) by the electron beam powder-bed-fusion process (EB-PBF) is identified as a potential technology to address these requirements. In this paper we reviewed the literature in EB-PBF of unalloyed tungsten to understand the role that the manufacturing parameters have in the microstructure and mechanical performance of as-printed specimens. We present targeted key research in tungsten EB-PBF process development using a modulated point melting method, post-AM hot isostatic pressing (HIP) treatment, destructive and non-destructive evaluation, microstructure control, and in-process monitoring. It was found that the modulated point melting method reduces cleavage cracking and crack nucleation points while elevated temperature HIP treatment improves the repeatability of the tensile behaviour, while mechanically healing process induced defects like solid-state cracks and nanopores.
{"title":"Investigating the microstructure of additively manufactured tungsten parts produced by electron beam powder bed fusion process","authors":"Miguel Zavala-Arredondo , Arun Ramanathan Balachandramurthi , Lidija Stjepanic Peric , Nick Weston , Katy Rankin , Sebastian Rosini , Khurram Amjad , Jeong-Ha You","doi":"10.1016/j.nme.2025.102011","DOIUrl":"10.1016/j.nme.2025.102011","url":null,"abstract":"<div><div>Pure tungsten is one of the promising candidate materials for plasma facing components (PFC) of future fusion reactors due to several favourable properties including its high melting point, high thermal conductivity, high strength, high sputtering resistivity and low coefficient of thermal expansion. Increasing geometric complexity and productivity of tungsten PFC is of interest to improve thermal performance and availability for new tokamaks with a view to future steady state plasma operation. Additive manufacturing (AM) by the electron beam powder-bed-fusion process (EB-PBF) is identified as a potential technology to address these requirements. In this paper we reviewed the literature in EB-PBF of unalloyed tungsten to understand the role that the manufacturing parameters have in the microstructure and mechanical performance of as-printed specimens. We present targeted key research in tungsten EB-PBF process development using a modulated point melting method, post-AM hot isostatic pressing (HIP) treatment, destructive and non-destructive evaluation, microstructure control, and in-process monitoring. It was found that the modulated point melting method reduces cleavage cracking and crack nucleation points while elevated temperature HIP treatment improves the repeatability of the tensile behaviour, while mechanically healing process induced defects like solid-state cracks and nanopores.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102011"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-14DOI: 10.1016/j.nme.2025.101989
Haowen Deng , Shouxi Gu , Qiang Qi , Guang-nan Luo
In liquid Pb-Li tritium breeding blanket, the compatibility between liquid Pb-Li and Reduced-activation-ferritic-martensitic (RAFM) steel structure material is crucial for the successful application of the RAFM steel. Corrosion experiments on CLF-1 steel in static Pb-Li at 550 ℃ were conducted for up to 1200 h to figure out the corrosion behavior and mechanism. After exposure, a subset of specimens was cleaned by mixed acid dissolution, while the remaining samples were cold-mounted in resin for cross-sectional observation. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Electron Backscatter Diffraction (EBSD) measurements were employed to characterize the corrosion behavior and reveal the corrosion mechanism. With increasing exposure time, corrosion initiates at grain boundaries and spreads laterally, producing boundary ditches, hollows, protrusions, and ultimately pebble‑like grains. It is proposed that corrosion occurs through the dissolution of Fe and Cr, facilitated by the diffusion of Li into the grain boundaries and grains, as well as the penetration and adsorption of Pb.
{"title":"Study on the corrosion behavior of static liquid Pb-16.7Li on the structural material CLF-1 steel","authors":"Haowen Deng , Shouxi Gu , Qiang Qi , Guang-nan Luo","doi":"10.1016/j.nme.2025.101989","DOIUrl":"10.1016/j.nme.2025.101989","url":null,"abstract":"<div><div>In liquid Pb-Li tritium breeding blanket, the compatibility between liquid Pb-Li and Reduced-activation-ferritic-martensitic (RAFM) steel structure material is crucial for the successful application of the RAFM steel. Corrosion experiments on CLF-1 steel in static Pb-Li at 550 ℃ were conducted for up to 1200 h to figure out the corrosion behavior and mechanism. After exposure, a subset of specimens was cleaned by mixed acid dissolution, while the remaining samples were cold-mounted in resin for cross-sectional observation. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Electron Backscatter Diffraction (EBSD) measurements were employed to characterize the corrosion behavior and reveal the corrosion mechanism. With increasing exposure time, corrosion initiates at grain boundaries and spreads laterally, producing boundary ditches, hollows, protrusions, and ultimately pebble‑like grains. It is proposed that corrosion occurs through the dissolution of Fe and Cr, facilitated by the diffusion of Li into the grain boundaries and grains, as well as the penetration and adsorption of Pb.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 101989"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-26DOI: 10.1016/j.nme.2025.102035
Andris Antuzevics , Guna Krieke , Jekabs Cirulis , Magdalena Rzepna , Maria Gonzalez , Julia M. Leys , Regina Knitter , Arturs Zarins
Advanced ceramic breeder (ACB) pebbles, primarily composed of lithium orthosilicate (Li4SiO4) with lithium metatitanate (Li2TiO3) as a second phase, are currently under development and testing as the European Union’s reference material for tritium breeding in future thermonuclear fusion reactors. In the present work, the formation and accumulation of paramagnetic radiation-induced defect centres is investigated and compared for the first time in the untreated and thermally pre-treated ACB pebbles under exposure to different types of ionising radiation. Electron paramagnetic resonance (EPR) spectroscopy is employed, with particular focus on correlating the detected EPR signals with the optical properties of the irradiated pebbles. The stability of the radiation-induced optical absorption bands and the positions of the main peaks in the thermally stimulated luminescence (TSL) glow curves are correlated to the annealing of the EPR signals at g = 2.04 and g = 2.00. Within the same temperature range, transformations occur among various radiation-induced electron-type centres, originating from structurally related sites formed in the bulk of the material. The annealing of these electron-type centres proceeds in multiple stages up to 350 °C, involving recombination with hole-type centres that exhibit different stabilities. The obtained results highlight the important role of paramagnetic centres in determining the optical properties of the irradiated ACB pebbles.
{"title":"Paramagnetic radiation-induced defect centres and their correlation with the optical properties of irradiated advanced ceramic breeder pebbles","authors":"Andris Antuzevics , Guna Krieke , Jekabs Cirulis , Magdalena Rzepna , Maria Gonzalez , Julia M. Leys , Regina Knitter , Arturs Zarins","doi":"10.1016/j.nme.2025.102035","DOIUrl":"10.1016/j.nme.2025.102035","url":null,"abstract":"<div><div>Advanced ceramic breeder (ACB) pebbles, primarily composed of lithium orthosilicate (Li<sub>4</sub>SiO<sub>4</sub>) with lithium metatitanate (Li<sub>2</sub>TiO<sub>3</sub>) as a second phase, are currently under development and testing as the European Union’s reference material for tritium breeding in future thermonuclear fusion reactors. In the present work, the formation and accumulation of paramagnetic radiation-induced defect centres is investigated and compared for the first time in the untreated and thermally pre-treated ACB pebbles under exposure to different types of ionising radiation. Electron paramagnetic resonance (EPR) spectroscopy is employed, with particular focus on correlating the detected EPR signals with the optical properties of the irradiated pebbles. The stability of the radiation-induced optical absorption bands and the positions of the main peaks in the thermally stimulated luminescence (TSL) glow curves are correlated to the annealing of the EPR signals at <em>g</em> = 2.04 and <em>g</em> = 2.00. Within the same temperature range, transformations occur among various radiation-induced electron-type centres, originating from structurally related sites formed in the bulk of the material. The annealing of these electron-type centres proceeds in multiple stages up to 350 °C, involving recombination with hole-type centres that exhibit different stabilities. The obtained results highlight the important role of paramagnetic centres in determining the optical properties of the irradiated ACB pebbles.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102035"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-22DOI: 10.1016/j.nme.2025.102016
Rongxing Yi , Rahul Rayaprolu , Jari Likonen , Salvatore Almaviva , Ionut Jepu , Gennady Sergienko , Anna Widdowson , Nick Jones , Sahithya Atikukke , Timo Dittmar , Juuso Karhunen , Pawel Gasior , Marc Sackers , Shweta Soni , Erik Wüst , Jelena Butikova , Wojciech Gromelski , Antti Hakola , Indrek Jõgi , Peeter Paris , Sebastijan Brezinsek
The tokamak JET achieved a groundbreaking milestone in nuclear fusion during its final deuterium–tritium experimental campaign (DTE-3) by setting a new world energy record [1]. To investigate in-vessel the fuel retention and wall material migration in JET post DT operation and clean-up phase with baking and glow discharge cleaning, a laptop-sized laser-induced breakdown spectroscopy (LIBS) system was deployed and mounted on a remote handling arm inside JET. The 800 ps (10 mJ) laser (wavelength 1064 nm) achieved a spatial and depth resolution of 130 μm and 180 nm on tungsten plasma-facing components (1000 pulses), respectively. Over 800 positions including beryllium first wall and tungsten divertor were studied by LIBS and provided both the spatial distribution and depth profiles of retained hydrogen (H) isotopes. LIBS spectra from four spectrometer systems enabled both high-resolution, high-sensitivity measurements and a broad spectral range simultaneously. Among them, a high throughput and high spectral resolution spectrometer in Littrow-arrangement was applied to distinguish the hydrogen isotopes. This in-vessel analysis demonstration provides vital information about the applicability of the technique for retention studies in future fusion reactors.
{"title":"In-vessel and depth-resolved semi-quantitative analysis on hydrogen isotopes and wall materials in JET by LIBS operated on a remote handling arm","authors":"Rongxing Yi , Rahul Rayaprolu , Jari Likonen , Salvatore Almaviva , Ionut Jepu , Gennady Sergienko , Anna Widdowson , Nick Jones , Sahithya Atikukke , Timo Dittmar , Juuso Karhunen , Pawel Gasior , Marc Sackers , Shweta Soni , Erik Wüst , Jelena Butikova , Wojciech Gromelski , Antti Hakola , Indrek Jõgi , Peeter Paris , Sebastijan Brezinsek","doi":"10.1016/j.nme.2025.102016","DOIUrl":"10.1016/j.nme.2025.102016","url":null,"abstract":"<div><div>The tokamak JET achieved a groundbreaking milestone in nuclear fusion during its final deuterium–tritium experimental campaign (DTE-3) by setting a new world energy record [<span><span>1</span></span>]. To investigate in-vessel the fuel retention and wall material migration in JET post DT operation and clean-up phase with baking and glow discharge cleaning, a laptop-sized laser-induced breakdown spectroscopy (LIBS) system was deployed and mounted on a remote handling arm inside JET. The 800 ps (10 mJ) laser (wavelength 1064 nm) achieved a spatial and depth resolution of 130 μm and 180 nm on tungsten plasma-facing components (1000 pulses), respectively. Over 800 positions including beryllium first wall and tungsten divertor were studied by LIBS and provided both the spatial distribution and depth profiles of retained hydrogen (H) isotopes. LIBS spectra from four spectrometer systems enabled both high-resolution, high-sensitivity measurements and a broad spectral range simultaneously. Among them, a high throughput and high spectral resolution spectrometer in Littrow-arrangement was applied to distinguish the hydrogen isotopes. This in-vessel analysis demonstration provides vital information about the applicability of the technique for retention studies in future fusion reactors.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102016"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-17DOI: 10.1016/j.nme.2025.102008
Zeyuan Sun , Xijie Wu , Ao Liu , Jie Pan , Zixie Wang , Mengli Li , Qiliang Mei , Jun Li , Xueshan Xiao
The phase transition behaviour and properties of Ti-Gd based alloys were investigated. The addition of Gd increases the α/β phase transition temperature of titanium alloys. The equiaxial α-phase in Ti-xGd alloys transforms into lamellar α-phase from 800 °C to 1000 °C. The addition of Fe element reduces the α/β phase transition temperature, and the α + β → β transition in Ti-7.5Fe-xGd alloys at temperatures between 600 °C and 800 °C. Gd elements precipitated as a second phase and alloys slip were impeded by the Gd phase during plastic deformation. The Ti-5.0Gd alloy exhibited good mechanical properties, with tensile strengths exceeding 500 MPa and elongation reaching up to 19.2 %. In addition, as the gadolinium content increases, there is a significant decrease in thermal neutron transmittance. When the alloy thickness is 0.07 cm, the shielding efficiency of the Ti-10.0Gd alloy for neutrons with an energy of 0.025 eV approaches 100 %. This indicates that the material exhibits excellent mechanical properties and effective thermal neutron shielding capabilities.
{"title":"Phase transition behaviour and properties of Ti-Gd based thermal neutron shielding alloys","authors":"Zeyuan Sun , Xijie Wu , Ao Liu , Jie Pan , Zixie Wang , Mengli Li , Qiliang Mei , Jun Li , Xueshan Xiao","doi":"10.1016/j.nme.2025.102008","DOIUrl":"10.1016/j.nme.2025.102008","url":null,"abstract":"<div><div>The phase transition behaviour and properties of Ti-Gd based alloys were investigated. The addition of Gd increases the α/β phase transition temperature of titanium alloys. The equiaxial α-phase in Ti-<em>x</em>Gd alloys transforms into lamellar α-phase from 800 °C to 1000 °C. The addition of Fe element reduces the α/β phase transition temperature, and the α + β → β transition in Ti-7.5Fe-<em>x</em>Gd alloys at temperatures between 600 °C and 800 °C. Gd elements precipitated as a second phase and alloys slip were impeded by the Gd phase during plastic deformation. The Ti-5.0Gd alloy exhibited good mechanical properties, with tensile strengths exceeding 500 MPa and elongation reaching up to 19.2 %. In addition, as the gadolinium content increases, there is a significant decrease in thermal neutron transmittance. When the alloy thickness is 0.07 cm, the shielding efficiency of the Ti-10.0Gd alloy for neutrons with an energy of 0.025 eV approaches 100 %. This indicates that the material exhibits excellent mechanical properties and effective thermal neutron shielding capabilities.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102008"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-19DOI: 10.1016/j.nme.2025.102031
A. Kirschner , C. Baumann , S. Brezinsek , Ch. Linsmeier , R.A. Pitts , A.A. Pshenov , J. Romazanov
The prompt redeposition of sputtered tungsten at the inner wall of ITER during current ramp-up has been simulated with the ERO code. Plasma parameters from SOLPS-ITER for a medium-density (with a peak electron density of 4E12 cm−3 at the inner wall) and a high-density (1E13 cm−3) case have been used as input for ERO. Simulations without anomalous cross-field diffusion for sputtered tungsten ions reveal peaked prompt redeposition profiles in poloidal direction. At the tangency point with largest electron temperature and density, maximum prompt redeposition fractions of about 60 % for the medium density and 80 % for the high density case occur. At a distance of 50 cm away from the tangency point, prompt redeposition decreases to 10 % (medium-density) and 20 % (high-density case). The simulations without anomalous cross-field diffusion show that the overall redeposition is the same as the prompt redeposition thus the overall redeposition is only due to prompt redeposition. An anomalous cross-field diffusion of 1 m2/s leads to slightly increased prompt redeposition, however, for both medium and high-density case there is now also a significant amount of non-prompt redeposition. The modelled profiles of prompt redeposition can be used as input for plasma simulation codes like SOLPS-ITER to improve the assumptions of net tungsten wall sources.
{"title":"Modelling of tungsten prompt redeposition at the inner wall of ITER during ramp-up","authors":"A. Kirschner , C. Baumann , S. Brezinsek , Ch. Linsmeier , R.A. Pitts , A.A. Pshenov , J. Romazanov","doi":"10.1016/j.nme.2025.102031","DOIUrl":"10.1016/j.nme.2025.102031","url":null,"abstract":"<div><div>The prompt redeposition of sputtered tungsten at the inner wall of ITER during current ramp-up has been simulated with the ERO code. Plasma parameters from SOLPS-ITER for a medium-density (with a peak electron density of 4E12 cm<sup>−3</sup> at the inner wall) and a high-density (1E13 cm<sup>−3</sup>) case have been used as input for ERO. Simulations without anomalous cross-field diffusion for sputtered tungsten ions reveal peaked prompt redeposition profiles in poloidal direction. At the tangency point with largest electron temperature and density, maximum prompt redeposition fractions of about 60 % for the medium density and 80 % for the high density case occur. At a distance of 50 cm away from the tangency point, prompt redeposition decreases to 10 % (medium-density) and 20 % (high-density case). The simulations without anomalous cross-field diffusion show that the overall redeposition is the same as the prompt redeposition thus the overall redeposition is only due to prompt redeposition. An anomalous cross-field diffusion of 1 m<sup>2</sup>/s leads to slightly increased prompt redeposition, however, for both medium and high-density case there is now also a significant amount of non-prompt redeposition. The modelled profiles of prompt redeposition can be used as input for plasma simulation codes like SOLPS-ITER to improve the assumptions of net tungsten wall sources.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102031"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-31DOI: 10.1016/j.nme.2025.102018
Huace Wu , Rongxing Yi , Sebastijan Brezinsek , Anne Houben , Marcin Rasinski , Rui Ding , Matej Mayer , Gennady Sergienko , Timo Dittmar , Hongbin Ding
The impact of the thickness and uniformity of boron (B) layer deposited by the boronization process, as well as the understanding of the layer’s lifetime and oxygen gettering effectivity, remains uncertain and real time diagnosis is required in future. Building upon our previous work, the picosecond laser-induced breakdown spectroscopy (ps-LIBS) technology with spatial resolution capability was further employed to detect B elements in B films deposited on tungsten (W)-substrates samples. By adjusting experimental parameters such as laser energy and spot size, and studying the spatiotemporal evolution of W and B elements, the optimal experimental parameters were determined. Under a laser spot diameter of 488 μm, a laser fluence of 9.6 J/cm2, a delay time of 30 ns, and a gate width of 600 ns were used to improve the limit of detection (LOD) of B by ps-LIBS. A set of samples with different B layer thicknesses on W-substrates from 5.6 to 151.5 nm was obtained through exposure of samples by magnetron sputtering in a laboratory arrangement and exposure of samples on a manipulator during two boronizations in the stellarator W7-X. The thickness of the B layers was measured by Focused Ion Beam combined with Scanning Electron Microscopy (FIB-SEM) and Nuclear Reaction Analysis (NRA). After extracting the net B signal from the LIBS spectra, a quantitative calibration curve and LOD of the B II-703.2 nm for the B layers on W-substrates were established for the first time. These results confirm that ps-LIBS technology holds promise for in situ diagnostics of ultrathin B layers, ranging from a few nm to 100 nm, on W-substrates in fusion devices after boronization.
{"title":"Ultrathin boron layer (a few nm to 100 nm) diagnostics on tungsten substrates via spatiotemporally resolved picosecond LIBS in a vacuum","authors":"Huace Wu , Rongxing Yi , Sebastijan Brezinsek , Anne Houben , Marcin Rasinski , Rui Ding , Matej Mayer , Gennady Sergienko , Timo Dittmar , Hongbin Ding","doi":"10.1016/j.nme.2025.102018","DOIUrl":"10.1016/j.nme.2025.102018","url":null,"abstract":"<div><div>The impact of the thickness and uniformity of boron (B) layer deposited by the boronization process, as well as the understanding of the layer’s lifetime and oxygen gettering effectivity, remains uncertain and real time diagnosis is required in future. Building upon our previous work, the picosecond laser-induced breakdown spectroscopy (ps-LIBS) technology with spatial resolution capability was further employed to detect B elements in B films deposited on tungsten (W)-substrates samples. By adjusting experimental parameters such as laser energy and spot size, and studying the spatiotemporal evolution of W and B elements, the optimal experimental parameters were determined. Under a laser spot diameter of 488 μm, a laser fluence of 9.6 J/cm<sup>2</sup>, a delay time of 30 ns, and a gate width of 600 ns were used to improve the limit of detection (LOD) of B by ps-LIBS. A set of samples with different B layer thicknesses on W-substrates from 5.6 to 151.5 nm was obtained through exposure of samples by magnetron sputtering in a laboratory arrangement and exposure of samples on a manipulator during two boronizations in the stellarator W7-X. The thickness of the B layers was measured by Focused Ion Beam combined with Scanning Electron Microscopy (FIB-SEM) and Nuclear Reaction Analysis (NRA). After extracting the net B signal from the LIBS spectra, a quantitative calibration curve and LOD of the B II-703.2 nm for the B layers on W-substrates were established for the first time. These results confirm that ps-LIBS technology holds promise for <em>in situ</em> diagnostics of ultrathin B layers, ranging from a few nm to 100 nm, on W-substrates in fusion devices after boronization.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102018"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-08DOI: 10.1016/j.nme.2025.101999
E.A. Hodille , D. Piccinelli , M. Bertoglio , T. Loarer , J. Dufour , J. Denis , E. Lascar , G. Ciraolo , P. Tamain , Y. Ferro , E. Geulin , A. Gallo , P. Moreau , S. Vartanian , R. Bisson , B. Pégourié , Y. Anquetin , J. Gaspar , Y. Corre , K. Dunnell , T. Wauters
A fuelling changeover experiment from Deuterium (D) to Hydrogen (H), and back has been performed in WEST to study the retention and removal in metallic devices with actively cooled ITER-grade tungsten divertor. The present study reports trapping-diffusion modelling of H and D in the W divertor during this session. In this model approach, the divertor is represented by multiple (radially distributed) 1D simulations. The plasma exposure conditions are calculated with soledge3x-eirene, delivering the heat and particle flux for each of the divertor bins. The material model is parametrized by reproducing a thermal desorption spectrometry experiment and an isotope exchange experiment on polycristalline tungsten. The simulated outgassing flux during the post-pulse phase of the changeover pulses are converted to H, HD and D partial pressure in the WEST vacuum vessel. The calculated pressure is one order of magnitude below the experimental one as only the contribution from the divertor is taken into account in this analysis. An additional source of H outgassing should be taken into account to recover the dynamics of the H partial pressure, especially during D plasma phases. However, the dynamics of HD and D pressure drop is similar in the simulations and experiments. Finally, the analysis of the divertor H/D inventory shows that the isotope exchange is efficient near the plasma exposed surface but is limited by the D/H migration towards the bulk.
{"title":"Modelling fuel retention in the W divertor during the D/H/D changeover experiment in WEST","authors":"E.A. Hodille , D. Piccinelli , M. Bertoglio , T. Loarer , J. Dufour , J. Denis , E. Lascar , G. Ciraolo , P. Tamain , Y. Ferro , E. Geulin , A. Gallo , P. Moreau , S. Vartanian , R. Bisson , B. Pégourié , Y. Anquetin , J. Gaspar , Y. Corre , K. Dunnell , T. Wauters","doi":"10.1016/j.nme.2025.101999","DOIUrl":"10.1016/j.nme.2025.101999","url":null,"abstract":"<div><div>A fuelling changeover experiment from Deuterium (D) to Hydrogen (H), and back has been performed in WEST to study the retention and removal in metallic devices with actively cooled ITER-grade tungsten divertor. The present study reports trapping-diffusion modelling of H and D in the W divertor during this session. In this model approach, the divertor is represented by multiple (radially distributed) 1D simulations. The plasma exposure conditions are calculated with <span>soledge3x-eirene</span>, delivering the heat and particle flux for each of the divertor bins. The material model is parametrized by reproducing a thermal desorption spectrometry experiment and an isotope exchange experiment on polycristalline tungsten. The simulated outgassing flux during the post-pulse phase of the changeover pulses are converted to H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, HD and D<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> partial pressure in the WEST vacuum vessel. The calculated pressure is one order of magnitude below the experimental one as only the contribution from the divertor is taken into account in this analysis. An additional source of H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> outgassing should be taken into account to recover the dynamics of the H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> partial pressure, especially during D plasma phases. However, the dynamics of HD and D<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> pressure drop is similar in the simulations and experiments. Finally, the analysis of the divertor H/D inventory shows that the isotope exchange is efficient near the plasma exposed surface but is limited by the D/H migration towards the bulk.</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 101999"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-09DOI: 10.1016/j.nme.2025.102000
D.N. Gautam , T.T. Tran , M. Fellinger , F. Aumayr , M. Rubel , D. Primetzhofer , E. Pitthan
Boronization in tokamak devices with tungsten (W) plasma facing components (PFC) may lead to the formation of mixed layers of W and boron (B) that can affect wall retention of plasma fuel species. In this study, deuterium (D) retention was investigated in W-B thin films with different stoichiometries as well as in pure W and B, grown on silicon (Si) substrates by means of magnetron sputter deposition. After pre-characterization, the layers were implanted with 1 keV D2+ ions to a fluence of 7 × 1017 D/cm2, followed by in-situ ion beam analysis. The samples were annealed to temperatures between 400–600 °C and in-situ ion beam analysis measurements were performed before, during and after the annealing process by simultaneous Elastic Recoil Detection Analysis and Rutherford Backscattering Spectrometry. The different B concentrations in the films led to significant differences in D retention, where higher boron concentrations resulted in higher deuterium retention immediately after implantation. After annealing, the lowest amount of retained D was observed for a W-to-B ratio of 2:1, with an areal density of 8 × 1013 D/cm2, about three times lower than for pure W. The highest retention of around 5 × 1016 D/cm2 after annealing to 600 °C was found for the pure B-film. Ex-situ electron microscopy techniques revealed significant morphological modifications due to implantation and/or annealing, including bubble formation (W film), W surface enrichment (B-rich film) and crack formation (W-rich film).
{"title":"Deuterium retention in sputter-deposited W-B layers: in-situ implantation and ion beam analysis during annealing","authors":"D.N. Gautam , T.T. Tran , M. Fellinger , F. Aumayr , M. Rubel , D. Primetzhofer , E. Pitthan","doi":"10.1016/j.nme.2025.102000","DOIUrl":"10.1016/j.nme.2025.102000","url":null,"abstract":"<div><div>Boronization in tokamak devices with tungsten (W) plasma facing components (PFC) may lead to the formation of mixed layers of W and boron (B) that can affect wall retention of plasma fuel species. In this study, deuterium (D) retention was investigated in W-B thin films with different stoichiometries as well as in pure W and B, grown on silicon (Si) substrates by means of magnetron sputter deposition. After pre-characterization, the layers were implanted with 1 keV D<sub>2</sub><sup>+</sup> ions to a fluence of 7 × 10<sup>17</sup> D/cm<sup>2</sup>, followed by in-situ ion beam analysis. The samples were annealed to temperatures between 400–600 °C and in-situ ion beam analysis measurements were performed before, during and after the annealing process by simultaneous Elastic Recoil Detection Analysis and Rutherford Backscattering Spectrometry. The different B concentrations in the films led to significant differences in D retention, where higher boron concentrations resulted in higher deuterium retention immediately after implantation. After annealing, the lowest amount of retained D was observed for a W-to-B ratio of 2:1, with an areal density of 8 × 10<sup>13</sup> D/cm<sup>2</sup>, about three times lower than for pure W. The highest retention of around 5 × 10<sup>16</sup> D/cm<sup>2</sup> after annealing to 600 °C was found for the pure B-film. Ex-situ electron microscopy techniques revealed significant morphological modifications due to implantation and/or annealing, including bubble formation (W film), W surface enrichment (B-rich film) and crack formation (W-rich film).</div></div>","PeriodicalId":56004,"journal":{"name":"Nuclear Materials and Energy","volume":"45 ","pages":"Article 102000"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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