Fusion Engineering and Design最新文献

{"title":"Advancements of testing activities for development of in-bore welding tool for large feeding pipes of in-vessel components","authors":"Donato Sorgente ,&nbsp;Rocco Salvato ,&nbsp;Vincenzo Claps ,&nbsp;Christian Bachmann ,&nbsp;Günter Janeschitz ,&nbsp;Rocco Mozzillo","doi":"10.1016/j.fusengdes.2025.115367","DOIUrl":"10.1016/j.fusengdes.2025.115367","url":null,"abstract":"<div><div>This work presents the results of welding tests made on large pipes (DN200) in austenitic stainless steel AISI316L to be used in the nuclear fusion DEMOnstration power plant, DEMO. Samples were designed and manufactured to physically simulate the coupling and the alignment of the two pipes and their joining by an in-bore welding system. The trajectories describing the movement of the TIG torch during the operation were selected for the specific geometric configuration where the multi-pass operation has to start from the outer diameter of the pipe and to proceed inwards. The temperature in the material close to the welding zone was monitored before and after each welding pass. The shielding gas (argon) was used on the top of the weld seam and, in a specific ad-hoc set of tests, also on the back side (back shielding) in order to check the need to protect the rear (external) part of the weld seam during the first passes. Destructive tests were then carried out to preliminarily assess the quality of the joint. Several pieces of information were collected including suitable process parameters, the time required to complete the individual joint and wear of the tungsten electrode.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115367"},"PeriodicalIF":1.9,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704177","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":"Vertical instability active controlled power supply of HL-3 tokamak","authors":"Zheng Xue,&nbsp;Xiong Zhenming,&nbsp;Liu Panle,&nbsp;Wang Yingqiao,&nbsp;Xuan Weimin,&nbsp;Li bo,&nbsp;Chen Yihang","doi":"10.1016/j.fusengdes.2025.115311","DOIUrl":"10.1016/j.fusengdes.2025.115311","url":null,"abstract":"<div><div>To mitigate plasma vertical instability and ensure high-quality physical experiments as well as the safety of the machine, the vertical instability active controlled power supply (VS PS) must respond rapidly to bias plasma vertical displacement events within the vacuum vessel. This paper presents the design of a cascaded H-bridge structure based on IGBT technology, marking the first implementation of a VS PS in the HL-3 tokamak. Unlike traditional power sources supplied by the grid, the VS PS is powered by a 300 MVA double Y six-phase motor-generator, which necessitates careful consideration of its unique supplying conditions. The modular design of the H-bridge allows for scalability to meet future demands for higher operational parameters. The cascaded H-bridge configuration enhances output voltage and reduces total harmonic distortion (THD) at the output side. The system effectively meets the control requirements for plasma vertical instability in the HL-3 tokamak, achieving a control response time of approximately 200 μs and managing plasma conditions under 1.6 elongation and 500 kA plasma current.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115311"},"PeriodicalIF":1.9,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702396","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":"Tritium permeation experiments; design choices and appropriateness to fusion application research","authors":"Teuntje Tijssen","doi":"10.1016/j.fusengdes.2025.115351","DOIUrl":"10.1016/j.fusengdes.2025.115351","url":null,"abstract":"<div><div>Tritium permeation is expected to be a major challenge in many locations in the fuel cycle of future fusion reactors. Countless permeation experiments have been performed trying to address this issue, each with their own characteristics including experimental conditions created, materials used, and detection methods employed. This paper reports the main outcomes of these past investigations, categorising them by their mode of operation rather than by the materials studied. The limitations of scientific experiments in recreating future conditions in fusion fuel cycles, and efforts to decrease this discrepancy, are discussed. Factors to consider when designing a permeation experiment and how these decisions affect the measurements that can be obtained are considered.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115351"},"PeriodicalIF":1.9,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702395","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":"Electrostatic and structural design analysis of CRAFT NNBI high voltage deck","authors":"Wei Hu ,&nbsp;Caichao Jiang ,&nbsp;Zhimin Liu ,&nbsp;Shiyong Chen ,&nbsp;Junjun Pan ,&nbsp;Sheng Liu ,&nbsp;Wei wei ,&nbsp;Bo Liu ,&nbsp;Yuanlai Xie","doi":"10.1016/j.fusengdes.2025.115360","DOIUrl":"10.1016/j.fusengdes.2025.115360","url":null,"abstract":"<div><div>The neutral beam system of the CRAFT negative ion source (CRAFT NNBI) requires the design and installation of a large-scale air-insulated Faraday cage high-voltage deck (HVD). The HVD is intended to house power supply equipment, high-temperature and High-Voltage water treatment systems, and various diagnostic devices. It must maintain an insulation voltage to ground at a direct current (DC) level of -400 kV, satisfy mechanical support requirements, and effectively shield against electromagnetic interference.This paper presents the electrostatic simulation design for the HVD, conducts static structural and seismic analyses, and finally evaluates and validates the design based on the simulation results. The findings will provide guidance for the subsequent optimization of the HVD.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115360"},"PeriodicalIF":1.9,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694311","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":"Progress and results of the first high voltage vacuum insulation tests in MITICA","authors":"T. Patton ,&nbsp;G. Chitarin ,&nbsp;N. Pilan ,&nbsp;M. Agostini ,&nbsp;D. Aprile ,&nbsp;M. Boldrin ,&nbsp;V. Candeloro ,&nbsp;M. Dan ,&nbsp;S. Denizeau ,&nbsp;N. Marconato ,&nbsp;A. Rigoni ,&nbsp;G. Manduchi ,&nbsp;F. Santoro ,&nbsp;E. Spada ,&nbsp;C. Taliercio ,&nbsp;L. Trevisan ,&nbsp;M. Valente ,&nbsp;L. Zanotto ,&nbsp;P. Barbato ,&nbsp;M. Fincato ,&nbsp;M. Kashiwagi","doi":"10.1016/j.fusengdes.2025.115349","DOIUrl":"10.1016/j.fusengdes.2025.115349","url":null,"abstract":"<div><div>The Heating Neutral Beam injector (HNB) for ITER includes a Beam Source (BS) surrounded by a single vacuum gap, operating up to 1 MV total voltage. MITICA (Megavolt ITER Injector &amp; Concept Advancement) is a full-scale prototype of the ITER Heating Neutral Beams (HNBs), devoted to test and optimize the design, under construction in Padova at the Neutral Beam Test Facility (NBTF) hosted by the Consorzio RFX.</div><div>Recent experiments on HV bushing for MITICA and reduced-scale models at QST lab in Naka, Ibaraki, Japan, indicate that the breakdown probability of the HNB insulation might be critical.</div><div>As a risk-mitigation measure for the HNB operation, a specific high-voltage test campaign has been undertaken in the MITICA test bed at NBTF. Full-size \"mock-up electrodes\", reproducing the outer geometry of the MITICA/HNB accelerator are used, allowing swift implementation and test of different electrostatic configurations in realistic conditions.</div><div>The main objectives are: (1) to verify the performance of the vacuum electrode insulation in the present design and: (2) to assess the minimal set of necessary modifications, possibly including the introduction of an intermediate electrostatic shield. All tests are foreseen during the time window before the installation of the real beam source in the MITICA vacuum vessel.</div><div>The paper describes the test strategy and the ad-hoc development of diagnostics, including current sensors in vacuum, integrated video camera system and data acquisition network, devoted to identify the most critical regions where an insulation breakdown could occur inside the large vacuum vessel.</div><div>Then, the results of the first test campaigns are presented and discussed, in terms of maximum withstand voltage of the insulation, in relation to electrode geometry, applied voltage rise time and vacuum conditioning procedure.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115349"},"PeriodicalIF":1.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686902","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, commissioning, and first operation of the high-temperature superconducting tokamak Honghuang70","authors":"Z. Yang,&nbsp;Y.J. Cao,&nbsp;B. Chen,&nbsp;G.B. Chen,&nbsp;W.J. Chen,&nbsp;G. Dong,&nbsp;Y.Q. Du,&nbsp;H.Y. Guo,&nbsp;Y.X. Guo,&nbsp;Y. Hua,&nbsp;Y. Huang,&nbsp;Y.Y. Li,&nbsp;Z.Y. Li,&nbsp;J.H. Liu,&nbsp;J.Q. Ma,&nbsp;Z.C. Pan,&nbsp;H. Qiao,&nbsp;Y.Z. Wang,&nbsp;Q.Q. Wei,&nbsp;H.G. Yang,&nbsp;Y.J. Zhu","doi":"10.1016/j.fusengdes.2025.115341","DOIUrl":"10.1016/j.fusengdes.2025.115341","url":null,"abstract":"<div><div>Honghuang70 (HH70) is the world’s first fully high-temperature superconducting (HTS) tokamak. It is a medium-sized tokamak with modest aspect ratio, featuring a major radius of <em>R₀</em> = 0.7 m and a minor radius <em>a</em> = 0.25 - 0.3 m. At the designed coil operation temperature of 20 K, the maximum designed magnetic field on the magnet coils is <em>B_max</em> = 2.5 T, and the toroidal magnetic field at the plasma center <em>B₀</em> = 0.6 T. All of HH70’s coils including the central solenoid (CS), the poloidal field (PF) coils and the toroidal field (TF) coils are constructed with the rare-earth barium copper oxide (ReBCO) HTS tape as the main current-carrying component. The construction and assembly of HH70 were completed in 2024. The coil commissioning results show that the behavior of the HTS coils agrees with engineering simulation results. The integrated commissioning has verified the capability of the supporting subsystems. This paper reviews the design, assembly, commissioning and initial operation of the HH70 tokamak, including its HTS coils and main supporting systems. The successful operation of HH70 demonstrates the feasibility of full-HTS tokamaks and provides valuable engineering experience.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115341"},"PeriodicalIF":1.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679714","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":"Upgrade of the Diagnostic Neutral Beam Injector for the RFX-mod2 experiment","authors":"Marco Barbisan ,&nbsp;Marco Boldrin ,&nbsp;Luca Cinnirella ,&nbsp;Bruno Laterza ,&nbsp;Alberto Maistrello ,&nbsp;Lionello Marrelli ,&nbsp;Federico Molon ,&nbsp;Simone Peruzzo ,&nbsp;Cesare Taliercio ,&nbsp;Marco Valisa ,&nbsp;Enrico Zampiva","doi":"10.1016/j.fusengdes.2025.115320","DOIUrl":"10.1016/j.fusengdes.2025.115320","url":null,"abstract":"<div><div>Diagnostic Neutral Beam Injectors (DNBI), through the combined use of Charge Exchange Recombination Spectroscopy (CHERS) and Motional Stark effect diagnostics (MSE), are a well-known tool to access important information about magnetically confined plasmas, such as radial profiles of ion temperature, ion flow, impurity content and intensity and direction of the magnetic field. For this purpose, a DNBI was installed and operated in the RFX-mod experiment, which was designed to confine plasma mainly through the Reversed Field Pinch configuration. The DNBI, designed and built by the Budker Institute of Nuclear Physics (BINP), was based on a source of positive hydrogen ions, accelerated to 50 keV and for a maximum ion current of 5 A. The beam could be modulated and the maximum overall duration was 50 ms.</div><div>With the upgrade of RFX-mod to the present RFX-mod2 machine, the DNBI is being renovated to solve several power units faults and improve the overall reliability of the system. The 50 kV power supply is being improved, as well as the power supplies in the high voltage deck and its insulation transformer. Magnetic field survival tests were performed on the toroidal-core-based DC–DC converters that should power the electronic boards in a reliable way. The control system, originally based on CAMAC technology, was redesigned to be fully replaced. This contribution reviews the technical criticalities emerged in the DNBI check-up and the new solutions adopted to make the DNBI operative and more reliable.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115320"},"PeriodicalIF":1.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679713","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":"On the potential and limitations of Bayesian ensemble algorithms for the decomposition of time series generated by tokamak diagnostics","authors":"Michela Gelfusa ,&nbsp;Teddy Craciunescu ,&nbsp;Riccardo Rossi ,&nbsp;Andrea Murari ,&nbsp;JET Contributors ,&nbsp;the EUROfusion Tokamak Exploitation Team","doi":"10.1016/j.fusengdes.2025.115318","DOIUrl":"10.1016/j.fusengdes.2025.115318","url":null,"abstract":"<div><div>The vast majority of signals generated by tokamak diagnostics are in the form of time series. Consequently dealing with time-indexed data is a major task, to be tackled daily by both experimentalists and analysts. Decomposing a time series in terms of seasonal components, trends, change-points and noise is therefore a crucial activity, per se and as a preliminary step to further investigations. In the present work, the Bayesian ensemble approach to model decomposition of time series, originally developed for remote sensing of the earth, is applied to various global measurements routinely available in tokamak devices. Among the competitive advantages of the methodology, particularly relevant are its holistic view of the data and the independence from the details of the statistical algorithms and models. The potential of the technique, implemented by the BEAST code, has been assessed with both synthetic signals and experimental data. The approach proves to be very reliable in modelling trends and determining the time locations of abrupt changes even of strongly oscillatory components, such as ELMs and sawteeth. Deployment to assess small drifts confirms the lack of stationarity in tokamak high performance discharges. The difficulties of modelling the details of the sawteeth and irregular ELMs indicate the need to improve the method to deal with seasonal components of complex harmonic content and/or varying frequency. However, the available routines are already very effective in determining the times changes in the ELM regimes.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115318"},"PeriodicalIF":1.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679770","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":"New progress on a compact deuterium-deuterium neutron generator based on RF ion source","authors":"Zhenqing Zhu ,&nbsp;Yuzhong Qian ,&nbsp;Mengmeng Li ,&nbsp;Xin Tao ,&nbsp;Zhi Dou ,&nbsp;Bing Hong ,&nbsp;Renli Zhu ,&nbsp;Wei Xu ,&nbsp;Lizhen Liang ,&nbsp;Chundong Hu","doi":"10.1016/j.fusengdes.2025.115353","DOIUrl":"10.1016/j.fusengdes.2025.115353","url":null,"abstract":"<div><div>This article presents a systematic optimization of a compact deuterium-deuterium neutron generator based on a RF ion source, significantly increasing the neutron yield by 6 times to 6.46 × 10⁹ n/s. The designed device employs a concave high-voltage vacuum feedthrough, increasing the overall breakdown strength of the device to 150 kV. Additionally, to improve the ion current extracted, an innovative ‘diffusion-type’ plasma chamber has been adopted, achieving an increase of over 20 % in beam extraction. Furthermore, it has been verified that under high thermal load conditions, the performance of the scandium target is superior to that of the titanium target, primarily due to the higher desorption temperature of deuterium from scandium compared to titanium. Finally, a stable neutron yield of over 5 × 10⁹ n/s was achieved, with an effective operating time exceeding 98 %. This result provides a solid technical foundation for further improving neutron imaging quality.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115353"},"PeriodicalIF":1.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679771","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":"Exploring the stability of blanket pebble bed with plasma events","authors":"Qigang Wu ,&nbsp;Mingzhun Lei ,&nbsp;Pinghui Zhao ,&nbsp;Zhao Liu ,&nbsp;Weibin Xi","doi":"10.1016/j.fusengdes.2025.115354","DOIUrl":"10.1016/j.fusengdes.2025.115354","url":null,"abstract":"<div><div>Plasma control instability is one of the inherent challenges in fusion reactors. Pebble beds, composed of assembled particles, are employed in blanket models to achieve neutron multiplication and tritium breeding using different materials. However, electromagnetic (EM) forces induced by plasma events can disturb the pebble bed, potentially altering its internal structure and the initial packing characteristics. These structural changes can significantly affect the physical properties and stability of the pebble beds. Despite its importance, studies investigating the structural behavior of pebble beds under the influence of EM force disturbances remain limited. This paper investigates the structural evolution of the Be pebble beds under the EM force perturbations in the fusion reactors. Using a coupled approach of Finite Element Analysis (FEA) and Discrete Element Method (DEM), the multiscale characteristics of the pebble bed are analyzed at mesoscopic and microscopic levels. Key factors, including the local packing factor, particle slip, force transmission, force chains, fabric anisotropy, wall forces, and energy dissipation, are systematically evaluated. The results indicate that EM force generated during plasma instability events significantly influence the pebble bed structure. EM force perturbations notably affect particle slip, fabric anisotropy, wall forces, and local packing factors, while the changes for the force chains are minimal. The force transmission within the pebble bed primarily aligns with the direction of the applied EM force. Additionally, the perturbation energy is mainly dissipated as frictional and strain energy. These findings provide valuable insights into the structural evolution of pebble beds under EM disturbances, offering guidance for improving the design and structural stability of pebble beds in fusion reactors.</div></div>","PeriodicalId":55133,"journal":{"name":"Fusion Engineering and Design","volume":"220 ","pages":"Article 115354"},"PeriodicalIF":1.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679772","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}