Fusion Engineering and Design最新文献

{"title":"Analysis of SDDR calculation method in a large tokamak model","authors":"Ylenia Kogovšek Žiber ,&nbsp;Klemen Ambrožič ,&nbsp;Igor Lengar","doi":"10.1016/j.fusengdes.2025.115459","DOIUrl":"10.1016/j.fusengdes.2025.115459","url":null,"abstract":"<div><div>Understanding the shutdown dose rate (SDDR) plays a crucial role in the operation and maintenance of a fusion reactor. It is particularly important to ensure the safety of personnel and the environment during maintenance and decommissioning phases. In addition, both the prediction and management of SDDR are necessary precautions in the design and operation of fusion reactors.</div><div>In the present study, SDDR is investigated on a simplified model of a large tokamak to achieve a better understanding of the calculation method, the rigorous two-step method (R2S). The JSIR2S code system, based on the R2S method, is currently being developed at the Jožef Stefan Institute and combines calculations with the MCNP transport code and the FISPACT inventory code. It has been evaluated against measurements at the TRIGA fission research reactor for fission applications, and in this work it is assessed for fusion applications as well.</div><div>The aim of this study is to perform SDDR calculations at different cooling times in a model of a fusion reactor using the JSIR2S code. An isotopic analysis was also carried out to identify the parent isotopes that contribute the most to the SDDR near the horizontal ports.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115459"},"PeriodicalIF":2.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221035","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":"Structural optimization method of transport manipulator for the BEST tokamak","authors":"Fei Li,&nbsp;Wusheng Chou","doi":"10.1016/j.fusengdes.2025.115433","DOIUrl":"10.1016/j.fusengdes.2025.115433","url":null,"abstract":"<div><div>This study proposes a novel structural optimization framework integrating kinematic and static performance for the transport manipulator of China’s Burning Plasma Experimental Superconducting Tokamak (BEST), outperforming traditional single-objective approaches. A 1T3R (one translational, three rotational degrees of freedom) configuration is selected based on task requirements and geometric constraints. Link lengths are optimized using Sequential Quadratic Programming (SQP), achieving a 3.43% workspace increase compared to the Lagrange multiplier method. Cross-sectional parameters are optimized using Non-dominated Sorting Genetic Algorithm II (NSGA-II), with hollow rectangular sections reducing deformation and weight, improving the payload-to-weight ratio. This scalable framework enhances kinematic performance and payload-to-weight ratio, offering a robust solution for fusion reactor maintenance.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115433"},"PeriodicalIF":2.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158433","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":"Optical characterization of a full scale rhodium coated first mirror for ITER Wide Angle Viewing System (WAVS) diagnostic","authors":"E. León-Gutierrez ,&nbsp;R. López Heredero ,&nbsp;C. Rodriguez ,&nbsp;M.C. Torquemada ,&nbsp;R. García-López ,&nbsp;J.M. Fernandez Marin ,&nbsp;C.L. Barber Daza ,&nbsp;C. Pastor ,&nbsp;M. Medrano ,&nbsp;R. Vila ,&nbsp;J.J. Piqueras ,&nbsp;F. Le Guern ,&nbsp;A. Pereira","doi":"10.1016/j.fusengdes.2025.115463","DOIUrl":"10.1016/j.fusengdes.2025.115463","url":null,"abstract":"<div><div>Several first mirrors are located at the front of the equatorial visible and infrared Wide Angle Viewing System (WAVS) diagnostic in ITER. Optical characterization of a full-scale WAVS spherical first mirror prototype, manufactured from stainless steel (SS316L) and coated were conducted. Optical reflectance in the visible range (400–1100 nm) and wavefront error were measured. An ad-hoc experimental setup was specifically developed to enable accurate reflectance measurements of large and curved mirrors. The measured wavefront error was Peak to Valley (PV) of 1.695 times the wavelength (λ) and a Root Mean Square (RMS) of 125.3 nm met the specified tolerances, and reflectance inhomogeneity across the aperture was below 10%. To assess coating stability, the mirror was subjected to three thermal cycles between 100 °C and 240 °C under high vacuum (10⁻⁹ MPa). Optical reflectance measurements performed before and after thermal cycling showed no significant changes, confirming the thermomechanical stability of the rhodium coating. These results validate both the manufacturing process and the coating performance, demonstrating the suitability of this mirror design for the demanding operational conditions of ITER’s WAVS diagnostic system.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115463"},"PeriodicalIF":2.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158954","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":"Microstructural analysis and mechanical implications of neutron-irradiated ITER-grade tungsten","authors":"Koray Iroc ,&nbsp;Dmitry Terentyev ,&nbsp;Wouter Van Renterghem ,&nbsp;Dominique Schryvers","doi":"10.1016/j.fusengdes.2025.115466","DOIUrl":"10.1016/j.fusengdes.2025.115466","url":null,"abstract":"<div><div>This study examines the microstructural and hardening response of two ITER-grade pure tungsten materials, which were exposed to neutron irradiation at 600 °C and 1000 °C up to a dose of ∼1 dpa. Two major types of defects, dislocation loops and nanovoids, are observed for both grades and analyzed with transmission electron microscopy. While the general morphology and subgrain structure remained stable under irradiation, the number density of defects decreased, and average defect size increased at the higher irradiation temperature. Nanovoids exhibited greater thermal stability than dislocation loops, which led to their predominance in the radiation-induced hardening, particularly at 1000 °C. Hardening contributions were assessed using the dispersed barrier model, which showed that voids contributed more significantly to hardening than loops at any irradiation temperature. Various superposition rules are applied for the total hardening effect and the best fit is provided by squared summation with the size-dependent coefficient of barrier strength. The findings highlight the importance of void control and defect sink engineering in optimizing tungsten for fusion applications. This research aims to provide insights for designing radiation-resistant tungsten microstructure for advanced fusion reactor applications by linking defect behavior with mechanical properties under neutron irradiation.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115466"},"PeriodicalIF":2.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221036","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":"Multiphase modelling of 1D and 2D pressure wave propagation in a liquid metal using compressibleInterFoam","authors":"Lorenzo Melchiorri,&nbsp;Amanda Piselli,&nbsp;Simone Siriano,&nbsp;Alessandro Tassone","doi":"10.1016/j.fusengdes.2025.115448","DOIUrl":"10.1016/j.fusengdes.2025.115448","url":null,"abstract":"<div><div>This study explores the use of OpenFOAM <span>compressibleInterFoam</span> solver to model pressure transients during loss-of-coolant accidents (LOCAs) in liquid metal breeding blankets (LM-BBs) of fusion reactors. In LM-BBs that adopt the separately-cooled architecture, the lead-lithium eutectic alloy (PbLi) serves as a tritium breeder and carrier and neutron multiplier, while the coolant is a secondary fluid such as helium or water. Under LOCA conditions, high-pressure coolant injection into PbLi can trigger complex two-phase flows and pressure shocks, posing significant risks to blanket integrity. The presence of reactive coolants, such as water, further complicates this scenario through exothermic reactions that amplify transient pressures and produce hydrogen, challenging current modelling tools ability to capture these coupled phenomena accurately. Given these constraints, we assess OpenFOAM capability to simulate representative LOCA transients in two-dimensional (2D) geometries. Validating against analytical benchmarks, we simulate helium or steam jets entering a stagnant, low-pressure PbLi pool, examining configurations with both a gas plenum and a fully liquid metal setup. A mesh sensitivity analysis highlights the significant effect of grid resolution on wave propagation, with coarser meshes dampening wave amplitude and delaying shock transmission. The results indicate that OpenFOAM can capture the primary dynamics of two-phase interactions and pressure transients within these prototypical setups. The findings underscore OpenFOAM potential as a flexible, extensible framework for fusion safety studies, though further development is necessary to incorporate critical LOCA phenomena like phase change, solid–fluid interactions, and magnetohydrodynamic effects. This work thus lays the foundation for advancing OpenFOAM-based tools capable of informing future experimental designs and enhancing safety assessments for fusion reactor LM-BBs.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115448"},"PeriodicalIF":2.0,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158956","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":"SOPHIA: A tokamak simulator","authors":"F. Janky ,&nbsp;A. Dnestrovskii ,&nbsp;S.Y. Medvedev ,&nbsp;V. Nemytov ,&nbsp;B. Vincent ,&nbsp;P.F. Buxton ,&nbsp;T. Erskine ,&nbsp;J. Sinha ,&nbsp;O. Asunta ,&nbsp;ST40 team","doi":"10.1016/j.fusengdes.2025.115447","DOIUrl":"10.1016/j.fusengdes.2025.115447","url":null,"abstract":"<div><div>SOPHIA is a tokamak simulator developed at Tokamak Energy Ltd. SOPHIA combines a transport code ASTRA coupled with an equilibrium solver SPIDER, a plasma control system and models of the actuators and synthetic diagnostics. The main goal of SOPHIA is to help session leaders and physicists in charge prepare for the experiment by predicting experimental outcome in a simulation given their experiment-defining reference waveforms and settings for the tokamak systems as well as the plasma control system. SOPHIA reads these waveforms and settings directly from the application used by session leaders to prepare real experiments, the Pulse Schedule Editor (PSE). Complimentary to its experimental input interface, SOPHIA simulation outcome is stored using a format and MDSplus data structure identical to that of real experimental results, enabling the use of the same TE applications as for real experimental data analysis – MDSplus Shot Viewer and ST40 Physics Viewer. Thus, SOPHIA is fully integrated with the ST40 experiment and SOPHIA simulation can simply be triggered with a click of a button, and in fact should generally be run prior to every discharge. Currently, SOPHIA can be used in several modes. On the plasma simulation side, one can use the predictive transport calculations in ASTRA code or else fix the pressure profile based on experimental data from a selected discharge, measured by Thomson scattering system. On the plasma control system (PCS) side, there is an option to use PCS internal plasma position estimator module, PFIT, just as in real experiments, and generate its magnetic sensor input from synthetic diagnostics inside SPIDER such as Rogowski coil currents, loop voltages or local magnetic sensors. Alternatively, one can pass on to the controllers the exact plasma parameters that SPIDER computes directly, such as plasma radial and vertical position, X-point locations, gaps to last closed flux surface and plasma current, bypassing the PCS internal PFIT code. SOPHIA’s simulator framework is developed in Simulink and MATLAB environment with effective memory coupling with C and Fortran codes: it can be run directly in MATLAB or as an executable compiled from C. Plasma control system, which includes controllers, supervision and actuator models (actuator models are part of SOPHIA, not part of PCS) is exactly the same as used in the experiments. This extends SOPHIA application to tackle complex control problems where the multi-physics and multiple input/output nature of the system is inherent to the plasma dynamics. Even more, SOPHIA’s integration with PSE manager and other applications used in operations, makes SOPHIA particularly well suited for training new session leaders and the ST40 operators. It speeds up learning curve and increases confidence in preparation for new experiments.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115447"},"PeriodicalIF":2.0,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158434","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":"Characteristics of a repetitive ELM-like pulsed plasma source and its damage effects on tungsten target","authors":"Liangwen Qi ,&nbsp;Shuai Liu ,&nbsp;Xiaodong Wen ,&nbsp;Manqiang Du ,&nbsp;Delong Guo ,&nbsp;Chenxi Ren","doi":"10.1016/j.fusengdes.2025.115456","DOIUrl":"10.1016/j.fusengdes.2025.115456","url":null,"abstract":"<div><div>Transient thermal load events have great effects on the service life of plasma-facing materials (PFCs) in tokamak steady-state operation. A compact-sized repetitive discharge coaxial gun plasma source is developed in order to simulate transient heat loads such as type I edge-localized modes (ELMs-I) in ITER. In this paper, the plasma characteristics of repeated coaxial gun and the damage effects of different frequencies on tungsten target are studied. At a constant initial condition (charging voltage, gas-flow), the voltage and current data reflects the discharge characteristics of the repeating plasma source. The gun produces helium plasma with an electron density of 1.6–2.0 × 10¹⁵ cm⁻³, an energy density of 0.2 MJ/m², and a pulse width of 0.6 ms. The local surface heating evolution of W is clearly observed with the camera during repeated pulsed plasma exposure. By changing the discharge frequency of coaxial gun, it is found that the heat accumulation effect and thermal stress on the surface of tungsten target are intensified with the increase of shock frequency. High-frequency thermal shocks led to enhanced melting and accelerated crack propagation, with residual stresses on the target surface being released through crack formation. The simulation experiment results provide valuable insights into the interaction mechanisms between plasma and the first wall material at different frequencies in tokamaks.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115456"},"PeriodicalIF":2.0,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158957","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":"Modeling and validation of a detritiation system with recombiner and wet scrubber for fusion fuel cycle: Steady-state analysis and dynamic control case study","authors":"Yoonjae Lee ,&nbsp;Wonho Lee ,&nbsp;Min Ho Chang ,&nbsp;Jae-Uk Lee ,&nbsp;Jeehoon Han","doi":"10.1016/j.fusengdes.2025.115452","DOIUrl":"10.1016/j.fusengdes.2025.115452","url":null,"abstract":"<div><div>Effective tritium management is essential for environmental safety and regulatory compliance in fusion fuel cycles. This study presents the development and validation of steady-state and dynamic models for a large-scale detritiation system (DS) that processes thousands of Nm³/h of tritium-contaminated air. The steady-state model was established by scaling up validated laboratory-scale models of a recombiner and a wet scrubber, achieving a detritiation factor exceeding 100. A dynamic model was subsequently developed to assess the transient response of the DS under accident scenarios involving sudden tritium releases. The simulation results revealed that without control, tritiated water emissions could exceed regulatory limits. To mitigate this, a proportional controller was implemented to regulate the liquid water flow rate in the wet scrubber based on real-time tritium concentration measurements. Rather than employing conventional tuning methods, a parametric study of the proportional gain (K_C) was conducted to evaluate the control performance across various scenarios and to ensure compliance under uncertain conditions. The analysis identified a threshold K_C for regulatory adherence and selected K_C = 14 as a practical compromise between emission reduction and water load. These models and control strategies support the safe and efficient design of DS operations under both steady-state and transient conditions.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115452"},"PeriodicalIF":2.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158955","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":"Screening of suitable and testable structural materials for a volumetric neutron source","authors":"G. Aiello ,&nbsp;C. Bachmann ,&nbsp;J. Henry ,&nbsp;G. Pintsuk ,&nbsp;M. Rieth ,&nbsp;D. Terentyev","doi":"10.1016/j.fusengdes.2025.115460","DOIUrl":"10.1016/j.fusengdes.2025.115460","url":null,"abstract":"<div><div>The construction of a dedicated Volumetric Neutron Source (VNS) has recently been proposed to de-risk the path towards the licensing of EU DEMO and to bring the required technologies, in particular the Breeding Blanket, to the required Technology Readiness Level. The programmatic goals, the operating conditions and the associated requirements of this machine are different from the fusion power machines (ITER, DEMO) considered until now in the European Research Roadmap. A critical analysis and a possible reassessment of the material choices for the Vacuum Vessel (VV) and In-Vessel Components established for ITER and DEMO is therefore a required preparatory step. Starting from the materials used in the ITER VV and Shielding Blanket, their limits w.r.t. maximum allowable dose are discussed and possible alternatives to maximize the lifetime of the facility are proposed. The materials currently considered for the EU-DEMO Breeding Blanket are recalled and an overview of their present development status is provided. Materials and joining issues for Divertor targets are also discussed. The gaps in materials properties and the needs for additional characterizations are identified. The purpose of this paper is to provide options and information for designers, exploring the operational space of the VNS, the final selection of materials depending on the strategic goals and design choices that will be set for the facility.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115460"},"PeriodicalIF":2.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158960","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":"Simulation and experimental study on dynamic characteristics of isolated contact for 100 kA pyrobreaker","authors":"Jifei Ye ,&nbsp;Hua Li ,&nbsp;Zhiquan Song ,&nbsp;Zhenhan Li ,&nbsp;Peng Fu","doi":"10.1016/j.fusengdes.2025.115462","DOIUrl":"10.1016/j.fusengdes.2025.115462","url":null,"abstract":"<div><div>The isolated contact of pyrobreaker is used to disconnect the electrical connection immediately upon pyrobreaker current contact opening and establish long-term insulation capability. The performance of isolated contact can directly affect the safety and reliability of the quench protection system. A combined research approach based on multi-physics simulation and experimental methods is proposed to study the explosive fracture process of the isolated contact in pyrobreaker. The dynamic propagation of the explosive shock wave is simulated using the Arbitrary Lagrangian-Eulerian (ALE) algorithm combined with fluid-solid coupling, allowing for a detailed analysis of the pressure distribution on the isolated contact under shock loading and the time-dependent response of their fracture velocity. To validate the numerical model, a shock wave-driven explosion experiment was designed and conducted. Then the high-speed camera was used to capture the displacement of insulation cylinder for cutting contact. The experimental results exhibited a high degree of consistency with the numerical simulation, and demonstrates that the design method of pyrobreaker is effective and reliable.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"222 ","pages":"Article 115462"},"PeriodicalIF":2.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158959","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}