Fusion Engineering and Design最新文献

{"title":"A multi-classifier disruption predictor based on optimized support vector machine on EAST","authors":"Dongmei Liu ,&nbsp;Xinli Zhu ,&nbsp;Shuangbao Shu ,&nbsp;Shun Wang ,&nbsp;Biao Shen ,&nbsp;Bihao Guo","doi":"10.1016/j.fusengdes.2025.115092","DOIUrl":"10.1016/j.fusengdes.2025.115092","url":null,"abstract":"<div><div>Plasma disruption presents a significant risk to the operation of tokamaks. In this study, we propose a multi-classifier disruption predictor based on the support vector machine optimized using an improved particle swarm optimization algorithm. This approach is specifically designed for the EAST experiments conducted since 2020. A dataset comprising 194 disruption and 401 non-disruption shots was selected to evaluate the predictor's performance. Twelve representative diagnostic signals were selected by analyzing the statistical characteristics of the data in the plasma current flattop phase, with each signal corresponding to a sub-classifier. The performance of each signal's sub-classifier predictor was considered, leading to the development of a weighting scheme for the prediction results. The final prediction result was obtained from a linear combination of these results by their respective weights. With optimized weight schemes, the predictor effectively identified plasma diagnostic signal features, achieving a true positive rate of 93.9 % and a false positive rate of &lt;4.99 %, indicating its ability to trigger alarms promptly. Overall, the results demonstrate the feasibility of the proposed approach for disruption prediction on EAST.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115092"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective diffusivity and solubility of gaseous tritium in selected microporous thermal insulation materials","authors":"A.S. Teimane ,&nbsp;E. Pajuste ,&nbsp;A. Actins ,&nbsp;P. Kalnina ,&nbsp;A. Zekunde ,&nbsp;A. Kizilovs ,&nbsp;D. Demange ,&nbsp;J. Somvanshi ,&nbsp;J. van der Laan","doi":"10.1016/j.fusengdes.2025.115026","DOIUrl":"10.1016/j.fusengdes.2025.115026","url":null,"abstract":"<div><div>Permeation, effective diffusivity and solubility experiments of tritium in thermal insulation materials proposed for ITER is vital for assessing the conditions required for the operation of the Test Blanket System, including its maintenance. With these results, simulation models can be prepared to predict tritium migration behaviour and therefore, air in the estimation of tritium inventory within the concerned components, and the concerned outgassing rates.</div><div>This paper looks at three different grades of microporous thermal insulation material, which have been tested for the behaviour of tritium in the form of HT. Effective diffusion coefficients, activation energy and effective solubility has been assess together with characterization of the material.</div><div>An effective diffusion coefficient, which involves gas transport through structure defects, has been evaluated based on Fick's law. Effective diffusivity results are obtained in the range of 1 to 5 × 10^–1 cm²/s and the results show no significant difference between the three grades analysed. Effective diffusivity was found to be significantly larger than in other silica-based materials, which can be explained by structural defects observed using SEM. Calculations show that the material's solubility is mostly dominated by its porosity.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115026"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the plasma characteristics in the extraction region of hybrid negative ion source","authors":"Huaiyu Luo,&nbsp;Peixuan Yu,&nbsp;Yinxiang Wan,&nbsp;Bowen Zhou,&nbsp;Hongxia Zhou,&nbsp;Xianfu Yang,&nbsp;Peiqin Tang,&nbsp;Chunzhe Zhang,&nbsp;Mei Huang,&nbsp;Huiling Wei,&nbsp;Shaofei Geng","doi":"10.1016/j.fusengdes.2025.115094","DOIUrl":"10.1016/j.fusengdes.2025.115094","url":null,"abstract":"<div><div>To experimentally investigate the beam optics performance of negative hydrogen ion sources under filament-arc(FA) discharge and radio-frequency (RF) discharge, the NBI group at Southwestern Institute of Physics(SWIP) has designed a negative hydrogen ion source, on which the researchers can independently carry out filament-arc discharge, RF-driven discharge, as well as simultaneous FA-RF hybrid discharge. When the plasma diffuses through the extraction region, the electron energy distribution function(EEDF) and spatial characteristics of the plasma are of primary interest to the researchers. In the SWIP FA-RF hybrid negative hydrogen ion source, a Langmuir probe installed in the extraction region is used to measure the fundamental parameters of the plasma, and the calculation of EEDF follows the Druyvesteyn analysis. Furthermore, the evolution process of plasma parameters in the extraction region during cesium seeding has also been investigated. Experimental results indicate that stochastic heating is the main mechanism for electron heating in the FA-RF hybrid negative hydrogen ion source. Increasing RF power substantially enhances both electron density and electron temperature. However, electron temperature remains unchanged when increasing the arc power. It has been found that the electron density decreases gradually throughout the cesium seeding process, while electron temperature remains relatively stable.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115094"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of high gamma-irradiation on hydraulic oils","authors":"Daoan Kang ,&nbsp;Rongrong Luo ,&nbsp;Chao Huang ,&nbsp;Jindou Liu ,&nbsp;Zhiyuan Zhang ,&nbsp;Hongxi Ren ,&nbsp;Pengyuan Li","doi":"10.1016/j.fusengdes.2025.115095","DOIUrl":"10.1016/j.fusengdes.2025.115095","url":null,"abstract":"<div><div>The effects of irradiation are crucial for the application of robots in nuclear environments. A key factor influencing the performance of hydraulic robots in these settings is the radiation resistance of hydraulic oil. This study investigates the patterns and mechanisms of static gamma-ray irradiation effects on aviation hydraulic oils No 10 and No 15 under various irradiation doses. Property analyses of the hydraulic oil samples, conducted before and after irradiation, demonstrate that both oils remain largely unaffected by doses below 10 kGy. However, at irradiation doses ranging from 100 kGy to 1 MGy, significant reductions in kinematic viscosity and initial boiling point are observed, accompanied with a sharp increase in acid number and potential. Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) analyses reveal the decomposition of tertiary alcohols into primary alcohols, as well as the transformation of long-chain alkanes and cycloalkanes into unsaturated C = C hydrocarbons. This decomposition, which intensifies with increasing irradiation doses, is identified as the primary cause of the observed properties deterioration, occurring primarily between the onset of irradiation and 1MGy. This study provides valuable theoretical and experimental insights for the application of aviation hydraulic oils in nuclear environments.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115095"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of core plasma power and current balance models for tokamak systems code considering H-mode plasma profiles","authors":"Shota Sugiyama ,&nbsp;Takuya Goto ,&nbsp;Hiroyasu Utoh ,&nbsp;Yoshiteru Sakamoto","doi":"10.1016/j.fusengdes.2025.115022","DOIUrl":"10.1016/j.fusengdes.2025.115022","url":null,"abstract":"<div><div>We propose the models for the systems codes to calculate the bootstrap current fraction, neutral beam-driven current, and synchrotron radiation loss power, considering the plasma profiles with the H-mode pedestals. The scaling formulae of the bootstrap current fraction are developed for the parabolic and H-mode plasma profiles by fitting the data prepared using a magnetohydrodynamic equilibrium calculation code including a detailed model of the bootstrap current. The developed simple model of the neutral beam-driven current is applicable to arbitrary plasma profiles and shapes. We show the geometric approximation of the flux surface averaged magnetic field strength, plasma surface area, and plasma volume to calculate the synchrotron radiation loss power using the CYTRAN module with only the parameters used in the systems codes. The validity of these models is confirmed by comparing the results to those calculated by the detailed models. These models enable the systems codes to consistently consider the plasma profiles with the pedestals in the core plasma power and current balances because the other quantities in the balance equations can be evaluated by calculating the profiles of the quantities and integrating them numerically within computing time acceptable for the systems analysis.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115022"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance study and comparison of vacuum RF circuits developed for first mirror plasma cleaning systems in ITER optical diagnostics","authors":"Andrey Ushakov ,&nbsp;Cederik Meekes ,&nbsp;Ulf Stephan ,&nbsp;Olaff Steinke ,&nbsp;Frank Stahr ,&nbsp;Corné Rijnsent ,&nbsp;Shriparna Mukherjee ,&nbsp;Peter Giesen ,&nbsp;André Rijfers ,&nbsp;Ad Verlaan ,&nbsp;Maarten de Bock ,&nbsp;Eiichi Yatsuka ,&nbsp;Michele Bassan ,&nbsp;Lucas Moser ,&nbsp;Erik van Beekum ,&nbsp;Shobhit Yadav","doi":"10.1016/j.fusengdes.2025.115073","DOIUrl":"10.1016/j.fusengdes.2025.115073","url":null,"abstract":"<div><div>In collection optics of many ITER optical diagnostics, first mirrors play a critical role for a robust optical system operation. To maintain the mirrors’ stable life-time performance, periodic in-situ plasma cleaning is developed using ion fluxes from a locally produced radio-frequency discharge. To enable efficient power transmission to the vacuum-plasma load, new impedance matching circuits were developed for installation behind the first mirror. Two new impedance matching prototypes were realized for two ITER large diagnostic systems (the Visible Spectroscopy Reference System and the Edge Thomson Scattering system). The prototype matching circuits comprising ceramic boards with metal layers were tested at the powers of 100–800 W at 40 MHz in the breadboards representing first mirror units of both systems to clean tungsten model contaminants. Frequency tuning was proposed as a lifetime measure to reduce the reflected power. Sputtering results in argon and helium plasma produced in the prototypes help to formulate possible cleaning recipes.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115073"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced magnetic diagnostic coils based on TPC technology for COMPASS-U and EU-DEMO","authors":"Pavel Turjanica ,&nbsp;Jan Reboun ,&nbsp;Ivan Duran ,&nbsp;Slavomir Entler ,&nbsp;Ladislav Viererbl ,&nbsp;Marek Simonovsky","doi":"10.1016/j.fusengdes.2025.115070","DOIUrl":"10.1016/j.fusengdes.2025.115070","url":null,"abstract":"<div><div>Magnetic diagnostic coils based on Thick Printed Copper (TPC) technology for COMPASS-U and EU-DEMO fusion reactors are introduced in this paper. Special emphasis is placed on the aspects of design and technology qualification. Firstly, the results of the tests carried out to qualify the TPC technology for the Tokamak environment are presented. Dedicated test samples were designed and temperature cycling irradiation and adhesion tests including electrical parameters measurements were executed. The aim of the TPC coil design was to achieve a high effective sensor area (up to 0.25 m²) and small dimensions compared to conventional coils. The coils can be composed from materials as Cu and Al₂O₃, AlN, or spinel (Al₂MgO₄) which ensures compatibility with elevated temperatures (at least 500 °C) and intense neutron radiation. Two coil variants, 1st with low winding density and 2nd with high winding density are proposed. Advanced layout of high-density coil winding achieving high suppression factor of cross-field sensitivity is presented. In parallel, the winding layout is also optimized to reduce parasitic radiation and temperature gradient induced side effects. Preliminary results of irradiation tests and temperature cycling test of TPC low winding density coil are presented.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115070"},"PeriodicalIF":1.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced Multi-Step Brazing (AMSB) for fabrication of new type of W/stainless steel first-wall component with ODS-Cu intermediate layer","authors":"Masayuki Tokitani ,&nbsp;Toyo Yamashita ,&nbsp;Yukinori Hamaji ,&nbsp;Suguru Masuzaki ,&nbsp;Shun Shimabukuro ,&nbsp;Kaori Kono ,&nbsp;Naoaki Yoshida ,&nbsp;Makoto Oya ,&nbsp;Takumi Onchi ,&nbsp;Ryuya Ikezoe ,&nbsp;Hiroshi Idei ,&nbsp;Kazuaki Hanada","doi":"10.1016/j.fusengdes.2025.115066","DOIUrl":"10.1016/j.fusengdes.2025.115066","url":null,"abstract":"<div><div>The novel method “Advanced Multi-Step Brazing (AMSB)” has been developed to fabricate a new type of “divertor” and “first-wall” heat removal component in a fusion reactor. This study is focused on the latter component, in which a tungsten (W) sheet is jointed through AMSB to a stainless steel (SUS) substrate via an oxide dispersion strengthened copper (ODS-Cu) intermediate layer. The principle of AMSB is a repetitive application of the advanced brazing technique (ABT). The initial purpose of the ABT was to braze W to ODS-Cu (GlidCop®) with the Ni-11 %P filler material. Later, we confirmed that the ABT is able to produce a very tough GlidCop® and SUS (GlidCop®/SUS) joint. One of the major advantages of GlidCop®/SUS joints is physically strong tolerance against the repetitive brazing heat-cycle. Thus, a repetitive application of the ABT does not cause any negative effects against post-brazed GlidCop®/SUS joints, and hence AMSB can be applied for fabricating a single heat-removal component with multiple joint interfaces. A small-scale sample of the new type of first-wall component was fabricated through two-step brazing. At first, the GlidCop® plate was jointed to the SUS by the ABT, and then a thin W-sheet with the thickness of 0.254 mm was jointed to GlidCop®/SUS by the ABT. If a large area of the first-wall surface in the fusion reactor can be covered with such a thin W-sheet, the amount of hydrogen isotopes trapped on the first-wall surface could be significantly reduced, compared to other fabrication methods such as a vacuum plasma spray W (VPS-W). The VPS-W is theoretically less dense than a W-sheet and often contains pore structures, which could act as effective trapping sites for hydrogen isotopes. A small-scale sample of the new type of first-wall component with a W-sheet (W/GlidCop®/SUS) was successfully fabricated to overcome the above disadvantages. In addition, the W surface of the component showed low retention characteristics of hydrogen isotopes compared with other W surfaces, e.g., atmospheric plasma-sprayed W (APS-W).</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115066"},"PeriodicalIF":1.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy optimization of the EFCC power supply in DTT scenarios","authors":"Pasquale Zumbolo ,&nbsp;Raffaele Albanese ,&nbsp;Andrea G. Chiariello ,&nbsp;Antonio Iaiunese ,&nbsp;Alessandro Lampasi ,&nbsp;Marco Neri ,&nbsp;Raffaele Martone","doi":"10.1016/j.fusengdes.2025.115049","DOIUrl":"10.1016/j.fusengdes.2025.115049","url":null,"abstract":"<div><div>The Divertor Tokamak Test facility comprises a sophisticated system designed to counteract Error Fields. The actual field correction demand will depend on the final characteristics of the assembled machine and, during operations, on the specific scenario instant. In this work, a comprehensive approach for the optimal design of the Error Field Correction Coil currents during the scenario is presented; the model is based on a circuit model of magnetic sources, including the correction coils, as well as Poloidal Field coils, Central Solenoid, plasma current and eddy currents. The available degrees of freedom are exploited to minimize the energy demand from correction coils power supplies while ensuring effective reduction of Error Fields.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115049"},"PeriodicalIF":1.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of divertor on tritium breeding in HELIAS","authors":"Tommi Lyytinen ,&nbsp;Antti Snicker ,&nbsp;Timo Bogaarts ,&nbsp;Felix Warmer","doi":"10.1016/j.fusengdes.2025.115000","DOIUrl":"10.1016/j.fusengdes.2025.115000","url":null,"abstract":"<div><div>This study presents tritium breeding calculations for the five-period helical-axis advanced stellarator (HELIAS) using the Serpent2 code. To address the absence of a detailed divertor design, a simplified divertor model with a layered homogenized structure was integrated into the parametric geometry of the HELIAS. The impact of the divertor on the tritium breeding ratio (TBR) was assessed through a parametric study, varying divertor configurations, surface area, materials for both the divertor and breeding blanket, and the thickness of the breeding zone behind the divertor. Calculated TBR losses relative to full blanket coverage ranged from 4 % to 35 %, depending on the specified input parameters. The primary factors influencing TBR loss were the fraction of surface area occupied by the divertor and the volume of the breeding zone displaced by it. A linear relationship was observed between TBR loss and both the divertor area fraction and the reduction in breeding zone volume. Furthermore, water-cooled divertor configurations showed a more negative impact on TBR compared to helium-cooled, with effects comparable in significance to variations in area fraction. The difference in TBR loss between purely TBR-optimized divertor configuration and Wendelstein 7-X-like top-bottom configuration was less than 2 percentage points.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"216 ","pages":"Article 115000"},"PeriodicalIF":1.9,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}