Fusion Engineering and Design最新文献

{"title":"Corroborating VNA and thermal measurements of transmission loss on the DIII-D ECH waveguide system","authors":"M.P. Ross ,&nbsp;K.A. Thackston ,&nbsp;A. Dupuy ,&nbsp;Y. Gorelov ,&nbsp;N. de Boucaud ,&nbsp;P. Nesbet ,&nbsp;A. Torrezan ,&nbsp;Z. Bayler ,&nbsp;N. Watson ,&nbsp;J. Anderson ,&nbsp;J.P. Squire","doi":"10.1016/j.fusengdes.2026.115626","DOIUrl":"10.1016/j.fusengdes.2026.115626","url":null,"abstract":"<div><div>Electron cyclotron heating (ECH) and current drive (ECCD) will play a large role in tokamak-based fusion reactors. At the DIII-D tokamak, 110 GHz microwaves injected into the plasma can provide core heating and current drive as well as impurity control, neoclassical tearing mode mitigation, and breakdown assistance. Understanding the physics of these processes relies on accurate estimates of injected ECH power. DIII-D’s ECH system consists of six MW-class Microwave Power Products (MPP) gyrotron microwave sources. Operating the gyrotrons far from the tokamak removes them from magnetic field interference, so 31.75 mm inner-diameter corrugated waveguides transmit the microwave power the 80 m from the gyrotrons to steerable launchers in the tokamak chamber. Estimates of injected power rely on knowing the generated power at the source and then subtracting transmission loss. Conventional transmission loss measurements based on calorimetric dummy loads are onerous and only possible during extended maintenance periods. This work examines two tools that provide more flexibility for the transmission loss measurements. A resistive temperature detector (RTD) array installed along a waveguide measures heat lost to the transmission line, and low power time domain reflectometry (TDR) measurements with a vector network analyzer (VNA) allows loss measurements without burdensome hardware modifications.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115626"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025282","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":"Mechanical analysis of tail structures in the next-generation fully superconducting tokamak CS HTS","authors":"Yi Yu ,&nbsp;HouXiang Han","doi":"10.1016/j.fusengdes.2026.115632","DOIUrl":"10.1016/j.fusengdes.2026.115632","url":null,"abstract":"<div><div>The Tail structure is a crucial component of high-temperature superconducting coils, providing both mechanical load transfer and reliable electrical connectivity between conductor leads. In this study, we designed and analyzed a Tail structure for a next-generation fully superconducting tokamak. We performed a coupled multi-physics analysis using finite element software to evaluate the mechanical performance of the proposed system under operational loads. The simulation revealed a maximum stress intensity of 1065.9 MPa, while linearized stress amplitudes remained within the allowable design limits, confirming adequate structural safety, and the minimum fatigue life of the structural components exceeds 127,000 cycles. We also developed and validated specialized welding fixtures through a series of welding experiments. All the welds successfully passed the quality inspections and met the technical specifications required for the procedure qualification, offering essential technical support for the construction of superconducting fusion devices.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115632"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025383","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":"Design and performance analysis of a high-current pulse inductor for fusion magnet quench protection","authors":"Wei Tong ,&nbsp;Meng Xu ,&nbsp;Hua Li ,&nbsp;Zhenhan Li ,&nbsp;Zhiquan Song ,&nbsp;Peng Fu","doi":"10.1016/j.fusengdes.2026.115641","DOIUrl":"10.1016/j.fusengdes.2026.115641","url":null,"abstract":"<div><div>Superconducting magnets in fusion devices are at the risk of quench during operation. Once quench occurs, the stored electromagnetic energy rapidly turns to Joule heat, potentially damaging the magnets severely. To protect these magnets, the Quench Protection System (QPS) employs high-power DC breaker to quickly interrupt the magnet current and transfer the quench energy, which relies on the LC circuit resonance to generate reverse pulsed current for creating a current zero-crossing point. This paper introduces the design and performance analysis of a high-current pulse inductor with toroidal helical structure. Its unique structure confines the magnetic field inside the coil, reducing interference and ensuring stability under pulse current. Targeting 20 μH inductance and 80 kA rated pulse current, the structural design of the inductor is performed firstly. Further, the Finite Element Method (FEM) is used to conduct a systematic simulation analysis of its electromagnetic, structural, and thermal performance. Finally, a prototype is also manufactured and subjected to LR parameter measurement and pulse high-current testing. Both simulation and test results show that the inductor has excellent magnetic confinement capability, outstanding structural stability, and reasonable temperature rise control ability.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115641"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079940","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":"Consideration of density measurement using toroidal interferometer and polarimeter on JA DEMO","authors":"K. Iwasaki ,&nbsp;S. Sugiyama ,&nbsp;Y. Ohtani ,&nbsp;Y. Sakamoto","doi":"10.1016/j.fusengdes.2026.115638","DOIUrl":"10.1016/j.fusengdes.2026.115638","url":null,"abstract":"<div><div>The toroidal interferometer and polarimeter (TIP) have been investigated as density diagnostics for JA DEMO. A model for the interferometer and polarimeter phase shifts incorporating the finite electron temperature effect has been implemented into a plasma control simulation code to generate the synthetic phase shift signals. The laser wavelength is set to <span><math><mrow><mn>10</mn><mo>.</mo><mn>6</mn><mspace></mspace><mi>μ</mi></mrow></math></span>m identical to that used in ITER. The finite temperature effect is significant. The deviation between the estimated line-averaged densities obtained with and without accounting for finite temperature effects reaches approximately 7% for the interferometer and 10% for the polarimeter along lines of sight near the magnetic axis, and decreases to a few percent near the outer edge. Density feedback control has been performed, and a comparison is made between the line-averaged densities with and without correction for the temperature effect. When the temperature effect is neglected, the density is underestimated, leading to an increase in the actual density. Consequently, the fusion output increases, resulting in an error of up to 11% when using the central viewing chords. Correction of the density error caused by the finite electron temperature has been carried out using TIP alone by taking the difference between the interferometer and polarimeter signals. The results show that it can reduce the density error to below 1%.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115638"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025233","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":"Investigation of the ultra-wideband polarizer for high power millimeter wave system","authors":"Feng Zhang,&nbsp;Mei Huang,&nbsp;Gangyu Chen,&nbsp;He Wang,&nbsp;Wanxin Zheng,&nbsp;Jieqiong Wang,&nbsp;Guoyao Fan,&nbsp;Cheng Chen","doi":"10.1016/j.fusengdes.2026.115630","DOIUrl":"10.1016/j.fusengdes.2026.115630","url":null,"abstract":"<div><div>As a crucial component of the electron cyclotron resonance heating (ECRH) system, the polarizer primarily serves to change the polarization characteristics of millimeter wave. In this study, an ultra-wideband polarization strategy based on two polarizers for the ECRH system is presented. By employing two identical sinusoidally grooved polarizers at a designated incident angle of 60°, it is possible to attain arbitrary polarization can be attained across an ultra-wideband frequency ranging from 99 GHz to 189 GHz. A ultra-wideband polarizer was devised and evaluated, and computational results indicate that the arbitrary polarization efficiency of the proposed method reaches at least 99.94%. According to this analysis, nearly every desired polarization state can be realized using the presented polarization strategy.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115630"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145963133","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":"Temperature-dependent ATR-FTIR calibration using a two-state spectral model for deuterium detection in water–manuscript draft-","authors":"Edouard Amadou,&nbsp;Jean Jules Fifen,&nbsp;Mama Nsangou,&nbsp;Pierre Doba","doi":"10.1016/j.fusengdes.2026.115656","DOIUrl":"10.1016/j.fusengdes.2026.115656","url":null,"abstract":"<div><div>Tritiated water will be present in many fusion demonstration facilities, in various forms and at highly heterogeneous concentrations. The implementation of fast and reliable measurement methods is therefore a critical requirement for process monitoring, radiological safety, and tritium traceability. This study evaluates the performance of attenuated total reflectance Fourier-transform infrared (ATR)-FTIR spectroscopy for the quantification of deuterium in aqueous solution, used here as a non-radioactive analogue of tritiated water (HTO). Measurements were conducted over a wide temperature range (0–74 °C) to replicate variable operational conditions. An excellent linear correlation (R² &gt; 0.99) was observed between infrared absorbance and D₂O concentration for the ν₁ and ν₃ vibrational modes, validating the applicability of the Beer-Lambert law under these conditions. Detection limits between 5.4 × 10⁻³ and 7.4 × 10⁻³ mol·mL⁻¹ were obtained, in accordance with IUPAC guidelines. While these values remain above the thresholds required for trace detection, they are compatible with the elevated concentrations expected in certain fusion subsystems. Lastly, the bending mode ν₂, although not calibrated in this work, exhibits promising thermal stability and may serve as a reference band in future applications. This study thus provides a realistic basis for the integration of ATR-FTIR spectroscopy into in situ tritium detection systems. p { margin-left: -0.01in; margin-right: -0.01in; text-indent: 0.32in; margin-bottom: 0.1in; direction: ltr; color: #000,000; line-height: 115%; text-align: justify; orphans: 2; widows: 2}p.western { font-family: \"Cambria\", serif; font-size: 12pt}p.cjk { font-family: \"Cambria\"; font-size: 12pt}p.ctl { font-family: \"Cambria\"</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115656"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173794","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":"Analysis and modelling of Inner Fuel Cycle performance using exhaust bypass and Direct Internal Recycling","authors":"Federico Hattab ,&nbsp;Yuri Igitkhanov ,&nbsp;Vincenzo Narcisi ,&nbsp;Alessia Santucci ,&nbsp;Fabio Giannetti ,&nbsp;Giulia Valeria Centomani ,&nbsp;Paul A. Staniec ,&nbsp;Richard Kembleton ,&nbsp;Thomas Giegerich","doi":"10.1016/j.fusengdes.2026.115668","DOIUrl":"10.1016/j.fusengdes.2026.115668","url":null,"abstract":"<div><div>Fusion power plants require robust fuel cycle (FC) architectures that minimize tritium inventories while managing impurity build-up and isotopic imbalances. This work investigates the performance of a Inner Fuel Cycle (IFC) architecture based on the Direct Internal Recycling (DIR) concept, with an additional bypass loop for recycling of exhaust gases utilized in gas puffing. Particular focus is given to fuel dilution due to impurity accumulation and deuterium–tritium (D–T) imbalance. A new Julia-based dynamic fuel cycle modeller, MINERVA (Modelling and Integration of Nuclear fusion Energy Reactor fuel cycle for Versatile Analysis), is introduces and used to evaluate the performances of the proposed architecture and for understanding the dynamics and criticalities of a DIR-based FC. Protium build-up is identified as a potential challenge, with accumulation becoming problematic at high separation efficiencies without dedicated removal systems. Two reactor case studies are analysed, EU DEMO 2018 and Gauss Fusion’s GIGA reactor. Results demonstrate that the proposed architecture effectively manages impurity concentrations below 1% for protium while maintaining optimal D–T ratios through active control systems. The proposed architecture achieves significant reductions in external fuel requirements, with effective conversion ratios growing exponentially with DIR separation efficiency. The bypass loop successfully provides the majority of gas puffing requirements without causing excessive impurity accumulation. This work establishes a foundation for advanced fuel cycle optimization studies essential for the development of commercial fusion power plants.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115668"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174230","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":"Particle and thermal transport in JET Helium and Hydrogen-Helium H-mode plasmas","authors":"I. Voitsekhovitch ,&nbsp;M. Poradzinski ,&nbsp;D. Taylor ,&nbsp;A. Chomiczewska ,&nbsp;H. Dudding ,&nbsp;I. Ivanova-Stanik ,&nbsp;D. King ,&nbsp;M. Maslov ,&nbsp;C. Roach ,&nbsp;JET contributors ,&nbsp;the EUROfusion Tokamak Exploitation Team","doi":"10.1016/j.fusengdes.2026.115664","DOIUrl":"10.1016/j.fusengdes.2026.115664","url":null,"abstract":"<div><div>Fusion performance in a tokamak-reactor strongly depends on the confinement of thermalised α-particles (Helium (He) ash) in the core plasma region. Consequently, the development of He particle transport models and their validation in present experiments is an important step towards a more accurate prediction of fusion power production in future devices. In the absence of a computationally fast well-validated theory-based transport models for He, the empirical Bohm-gyroBohm (BgB) model is tested here for the first time to our knowledge in the predictive self-consistent temperature and density simulations of JET H-mode He and Hydrogen (H) - He discharges. The thermal confinement in JET He plasmas is found to be well below the Deuterium (D) BgB model reference – this result is qualitatively consistent with the observation of reduced global thermal confinement in He discharges observed on ASDEX Upgrade, Cmod, DIII-D and EAST tokamaks compared to the confinement of D plasmas. The “Helium” version of the BgB model including the re-calibrated BgB thermal diffusivity and the He particle diffusion coefficient defined as a fixed fraction of the thermal electron diffusivity is proposed here. This model is validated in the JET discharges performed at different toroidal magnetic fields, plasma densities, wall materials (Carbon and ITER-like wall) and main ion compositions. Strong reduction of He particle transport with the increase of magnetic field has been found in JET discharges. However, the simulations of the He ash accumulation in the future high-field tokamak-reactor ARC with the model validated in JET predict a tolerable amount of He content in the burn phase in the investigated parameter space, with a weak impact on the fusion power production. Similar conclusion has been drawn for the H-mode EU-DEMO scenario by extrapolating the JET He particle transport model to this device.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115664"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174233","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":"Novel divertor target structural design for extreme heat load: FEM Simulation and experimental validation","authors":"Yu-zhong Jin ,&nbsp;You-yun Lian ,&nbsp;Jian-bao Wang ,&nbsp;Fan Feng ,&nbsp;Cheng-ming Tu ,&nbsp;Dong zhao ,&nbsp;Hao Wang ,&nbsp;Zong-jian Chai ,&nbsp;Zi-jie Wang ,&nbsp;Xiang Liu","doi":"10.1016/j.fusengdes.2026.115653","DOIUrl":"10.1016/j.fusengdes.2026.115653","url":null,"abstract":"<div><div>Designed heat flux as 10 MW m⁻² during stationary operation can be foreseen for ITER divertor tungsten, while the heat flux would be increased to even 20 MW m⁻² for future fusion devices. Design of advanced divertor target structure with enhanced cooling ability and prolonged lifetime is a popular research direction at present. In this paper, a new divertor target structure that combines flat tile concept and monoblock concept has been proposed. Finite Element Method (FEM) has been used to compare the thermal response as well as the service lifetime between ITER-like divertor monoblock and the novel divertor structure. Low-cycle fatigue damage and thermal creep rupture has been considered during simulation. A linear rule criterion has been applied to roughly estimate the creep-fatigue interaction on the armor material. The results show the novel divertor structure owns better heat transfer capability and it is expected to own longer service lifetime than ITER-like monoblock. Furthermore, high heat flux experiments have been conducted to verify its heat removal ability and structural reliability.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115653"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173790","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":"A confinement ventilation system zoning mode of nuclear fusion facilities based on equilibration time","authors":"Junhao Rong,&nbsp;Bin Guo,&nbsp;Jiansheng Hu,&nbsp;Muhammad Salman Khan,&nbsp;Jinxuan Zhou,&nbsp;Yuqing Tang,&nbsp;Gang Wu","doi":"10.1016/j.fusengdes.2026.115643","DOIUrl":"10.1016/j.fusengdes.2026.115643","url":null,"abstract":"<div><div>In tritium-handling fusion facilities, the heating, ventilation, and air conditioning (HVAC) system must not only satisfy thermal comfort and indoor air quality requirements but also ensure dynamic confinement to prevent the spread of radioactive materials, which is also called confinement ventilation system (CVS). According to ISO 16646 and ISO 17873, negative-pressure zoning within the CVS is adopted to control the risk of unconfined tritium release. However, for auxiliary rooms located inside tritium-controlled areas without any radioactive source terms, there remains no clear zoning strategy. Improper zoning of auxiliary rooms may lead to difficulties in achieving equilibration or increase the risk of CVS instability. To address this issue, a three-layer nested dilution-ventilation model was established based on the dilution ventilation equation and mass conservation principles. Case analyses show that increasing the volume of auxiliary spaces within the nested negative-pressure system does not vary the final equilibration concentration or total radioactive quantity, but it extends the equilibration time. Besides, equilibration time shows the linear increasing variations with <em>V/q_v</em> in each zones. Conversely, setting an auxiliary space to positive or normal pressure reduces the total radioactive quantity. Breaking the nest negative pressure chain and significantly increasing the equilibration time in low concentration area will be the two main drawback. Finally, three different zoning recommendations for auxiliary rooms are evaluated, based on the indicators consideration of CVS system safety, flow-rate, and ventilation equilibration time. The findings offer practical guidance for ventilation zoning design and commissioning in tritium-bearing fusion buildings.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"225 ","pages":"Article 115643"},"PeriodicalIF":2.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173792","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}