Nuclear Fusion最新文献_第9页

Overview of damage to beryllium limiters by unmitigated disruptions and runaway electrons in the JET tokamak with metal walls 带金属壁的 JET 托卡马克中未缓解的干扰和失控电子对铍限幅器的损害概述

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-22 DOI: 10.1088/1741-4326/ad6614

I. Jepu, A. Widdowson, Guy Matthews, J. Coad, J. Likonen, S. Brezinsek, M. Rubel, G. Pintsuk, Per Petersson, E. Fortuna-Zalesna, Justyna Grzonka, C. Porosnicu, P. Dinca, O. Pompilian, B. Butoi, Sorin Georgian Moga, S. Silburn, Slava Kuksenko, Eduardo Alves, N. Catarino, R. Pitts, Lei Chen, S. Ratynskaia

{"title":"Overview of damage to beryllium limiters by unmitigated disruptions and runaway electrons in the JET tokamak with metal walls","authors":"I. Jepu, A. Widdowson, Guy Matthews, J. Coad, J. Likonen, S. Brezinsek, M. Rubel, G. Pintsuk, Per Petersson, E. Fortuna-Zalesna, Justyna Grzonka, C. Porosnicu, P. Dinca, O. Pompilian, B. Butoi, Sorin Georgian Moga, S. Silburn, Slava Kuksenko, Eduardo Alves, N. Catarino, R. Pitts, Lei Chen, S. Ratynskaia","doi":"10.1088/1741-4326/ad6614","DOIUrl":"https://doi.org/10.1088/1741-4326/ad6614","url":null,"abstract":"\u0000 The Joint European Torus (JET) fusion reactor was upgraded to the metallic wall configuration in 2011 which consisted of bulk beryllium (Be) tiles in the main chamber and bulk tungsten (W) and W-coated CFC tiles in the divertor [1]. During each campaign, a series of wall damages were observed; on the upper dump plates (UDP) positioned to the top part of the vessel walls and on the inner wall - mainly affecting the inner wall guard limiters (IWGL). In both cases, it was concluded that the causes of these damages were unmitigated plasma disruptions. In the case of JET with the metallic wall configuration, most of these plasma disruptions were intentionally provoked. The overall objective was to study the behaviour of these phenomena, in order to assess their impact on the wall, improve understanding of morphological material changes, and – based on that - to develop, implement and test mitigation techniques for their prospective use on ITER. The current results bring additional information on the effects of the unmitigated plasma disruptions on the UDPs and are a significant extension of work presented in [2] where the scale of the damage after three operational campaigns on the Be top limiters of JET was highlighted. In addition, new data is presented on the damaging effect that the high energetic runaway electrons had on the Be IWGL in JET.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141816259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Demonstration of aneutronic p-11B reaction in a magnetic confinement device 磁约束装置中的非中子 p-11B 反应演示

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-22 DOI: 10.1088/1741-4326/ad6615

K. Ogawa, Richard Magee, Toshiki Tajima, H. Gota, P. McCarroll, I. Allfrey, H. Nuga, Mitsutaka Isobe, M. Osakabe

{"title":"Demonstration of aneutronic p-11B reaction in a magnetic confinement device","authors":"K. Ogawa, Richard Magee, Toshiki Tajima, H. Gota, P. McCarroll, I. Allfrey, H. Nuga, Mitsutaka Isobe, M. Osakabe","doi":"10.1088/1741-4326/ad6615","DOIUrl":"https://doi.org/10.1088/1741-4326/ad6615","url":null,"abstract":"\u0000 Aneutronic fusion using commonly available fuel such as hydrogen and boron 11 (11B) is one of the most attractive potential energy sources. On the other hand, it requires 30 times higher temperature than deuterium-tritium fusion in a thermonuclear fusion reactor condition. Development of techniques to realize its potential for the experimental capability to produce proton-boron 11 (p-11B) fusion in the magnetically confined fusion device using neutral beam injection is desired. Here we report clear experimental exploration and measurements of p-11B fusion reactions supported by intense hydrogen beams and impurity powder dropper installed in the magnetic confinement plasma Large Helical Device. We measured a significant amount of fusion alpha particle emission using a custom designed alpha particle detector based on a passivated implanted planar silicon detector. Intense negative-ion-based hydrogen beam injectors created a large population of up to 160 keV energetic protons to react with the boron-injected plasma. The p-11B alpha particles having MeV energy were measured with the alpha particle detector which gave a fusion rate in a good agreement with the global p-11B alpha emission rate calculated based on classical confinement of energetic proton, using experimentally obtained plasma parameters.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Divertor heat load estimates on NSTX and DIII-D using new and open-source 2D inversion analysis code 使用新的开源二维反演分析代码估算 NSTX 和 DIII-D 上的分流器热负荷

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-22 DOI: 10.1088/1741-4326/ad60dd

P.O. Adebayo-Ige, K.F. Gan, C.J. Lasnier, R. Maingi and B.D. Wirth

{"title":"Divertor heat load estimates on NSTX and DIII-D using new and open-source 2D inversion analysis code","authors":"P.O. Adebayo-Ige, K.F. Gan, C.J. Lasnier, R. Maingi and B.D. Wirth","doi":"10.1088/1741-4326/ad60dd","DOIUrl":"https://doi.org/10.1088/1741-4326/ad60dd","url":null,"abstract":"A thermography inversion algorithm has been developed in the open-source Python-based computer code, HYPERION, to calculate the heat flux incident on plasma-facing components (PFCs) in axisymmetric tokamaks. The chosen mesh size at the surface significantly affects the calculated transient heat flux results. The calculated transient heat flux will exceed the real value when the mesh size tends to zero but will underestimate the real value when the mesh size is large. A criterion for determining the appropriate mesh size for the transient heat flux calculation will be discussed. The numerical scheme for HYPERION uses a 2D fully implicit finite-difference approach, allowing temperature-dependent thermal properties of PFC materials. The inversion algorithm is benchmarked against established heat flux calculation codes, TACO and THEODOR, based on thermography data from NSTX and DIII-D respectively. The primary benefits of HYPERION compared to TACO and THEODOR are that it is open-source and it allows for the optimization of mesh thickness along the substrate. The algorithm also accounts for the thermal properties of thin surface layers that characteristically form on PFCs due to plasma-material interactions. The agreement between HYPERION and THEODOR is excellent, as the percent difference between the codes is ∼5% on average in the case of the DIII-D data for moderate to high heat flux. Verification tests with TACO show slightly higher average percent differences of 8% and 12%. In using HYPERION to study filaments in heat flux, the initial results indicate that small ELMs filaments significantly broaden the divertor heat flux, and decrease divertor peak flux. Compared to the inter-ELM, the small ELM filaments decrease the divertor peak surface temperature. With intermittent divertor filaments, the divertor heat flux width is comparable with that found in L-mode.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141753916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Plasma performance and operational space with an RMP-ELM suppressed edge 具有 RMP-ELM 抑制边缘的等离子体性能和运行空间

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-22 DOI: 10.1088/1741-4326/ad6014

C. Paz-Soldan, S. Gu, N. Leuthold, P. Lunia, P. Xie, M.W. Kim, S.K. Kim, N.C. Logan, J.-K. Park, W. Suttrop, Y. Sun, D.B. Weisberg, M. Willensdorfer, the ASDEX Upgrade Team, the DIII-D Team, the EAST Team and the KSTAR Team

{"title":"Plasma performance and operational space with an RMP-ELM suppressed edge","authors":"C. Paz-Soldan, S. Gu, N. Leuthold, P. Lunia, P. Xie, M.W. Kim, S.K. Kim, N.C. Logan, J.-K. Park, W. Suttrop, Y. Sun, D.B. Weisberg, M. Willensdorfer, the ASDEX Upgrade Team, the DIII-D Team, the EAST Team and the KSTAR Team","doi":"10.1088/1741-4326/ad6014","DOIUrl":"https://doi.org/10.1088/1741-4326/ad6014","url":null,"abstract":"The operational space and global performance of plasmas with edge-localized modes (ELMs) suppressed by resonant magnetic perturbations (RMPs) are surveyed by comparing AUG, DIII-D, EAST, and KSTAR stationary operating points. RMP-ELM suppression is achieved over a range of plasma currents, toroidal fields, and RMP toroidal mode numbers. Consistent operational windows in edge safety factor are found across devices, while windows in plasma shaping parameters are distinct. Accessed pedestal parameters reveal a quantitatively similar pedestal-top density limit for RMP-ELM suppression in all devices of just over m−3. This is surprising given the wide variance of many engineering parameters and edge collisionalities, and poses a challenge to extrapolation of the regime. Wide ranges in input power, confinement time, and stored energy are observed, with the achieved triple product found to scale like the product of current, field, and radius. Observed energy confinement scaling with engineering parameters for RMP-ELM suppressed plasmas are presented and compared with expectations from established H and L-mode scalings, including treatment of uncertainty analysis. Different scaling exponents for individual engineering parameters are found as compared to the established scalings. However, extrapolation to next-step tokamaks ITER and SPARC find overall consistency within uncertainties with the established scalings, finding no obvious performance penalty when extrapolating from the assembled multi-device RMP-ELM suppressed database. Overall this work identifies common physics for RMP-ELM suppression and highlights the need to pursue this no-ELM regime at higher magnetic field and different plasma physical size.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141753993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

WEST full tungsten operation with an ITER grade divertor 使用国际热核聚变实验堆级分流器进行 WEST 全钨操作

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-18 DOI: 10.1088/1741-4326/ad64e5

J. Bucalossi, Annika Ekedahl

{"title":"WEST full tungsten operation with an ITER grade divertor","authors":"J. Bucalossi, Annika Ekedahl","doi":"10.1088/1741-4326/ad64e5","DOIUrl":"https://doi.org/10.1088/1741-4326/ad64e5","url":null,"abstract":"\u0000 The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation in a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with a focus on testing the ITER actively cooled W divertor in tokamak conditions. Following the successful completion of phase 1 (2016-2021), phase 2 started in December 2022 with the lower divertor made entirely of actively cooled ITER-grade tungsten mono-blocks. A boronization prior the first plasma attempt allowed for a smooth startup with the new divertor. Despite the reduced operating window due to tungsten, rapid progress has been made in long pulse operation, resulting in discharges with a pulse length of 100 s and an injected energy of around 300 MJ per discharge. Plasma startup studies were carried out with equatorial boron nitride limiters to compare them with tungsten limiters, while ICRH assisted startup was attempted. High fluence operation in attached regime, which was the main thrust of the first campaigns, already showed the progressive build up of deposits and appearance of dust, impacting the plasma operation as the plasma fluence increased. In total, the cumulated injected energy during the first campaigns reached 43 GJ and the cumulated plasma time exceeded 5 hours. Demonstration of controlled X-Point Radiator regime is also reported, opening a promising route for investigating plasma exhaust and plasma-wall interaction issues in more detached regime. This paper summarises the lessons learned from the manufacturing and the first operation of the ITER-grade divertor, describing the progress achieved in optimising operation in a full W environment with a focus on long pulse operation and plasma wall interaction.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141827373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Corrigendum: Tritium burn efficiency in deuterium–tritium magnetic fusion (2023 Nucl. Fusion 63 126019) 更正：氘氚磁聚变中的氚燃烧效率（2023 Nucl.）

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-18 DOI: 10.1088/1741-4326/ad6337

D.G. Whyte, R. Delaporte-Mathurin, S.E. Ferry and S. Meschini

引用次数: 0

Horizontal homing laser for high repetitive inertial fusion 用于高重复惯性聚变的水平寻的激光器

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-18 DOI: 10.1088/1741-4326/ad64e8

Kazuhiro Agatsuma, Kohei Suzuki, Takuya Sugimoto, Kazuki Matsuo, Kenjiro Takahashi, Eiji Sato, Neisei Hayashi, Katsuhiro Ishii, Yoshitaka Mori

引用次数: 0

Initial testing of Alfvén Eigenmode feedback control with machine-learning observers on DIII-D 在 DIII-D 上利用机器学习观测器对阿尔芬特征模式反馈控制进行初步测试

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-18 DOI: 10.1088/1741-4326/ad64e6

Andrew Rothstein, A. Jalalvand, J. Abbate, K. Erickson, E. Kolemen

{"title":"Initial testing of Alfvén Eigenmode feedback control with machine-learning observers on DIII-D","authors":"Andrew Rothstein, A. Jalalvand, J. Abbate, K. Erickson, E. Kolemen","doi":"10.1088/1741-4326/ad64e6","DOIUrl":"https://doi.org/10.1088/1741-4326/ad64e6","url":null,"abstract":"\u0000 A first of its kind fully data-driven system has been developed and implemented into the DIII-D plasma control system to detect and control Alfvén Eigenmodes (AE) in real-time. Susceptibility to fast ion-induced AE is a challenge in fully non-inductive tokamak operation, which significantly reduces fast-particle confinement and results in degraded fusion gain. Controlling AEs in real-time to improve fast-ion confinement is, hence, important for future Advanced Tokamak fusion reactors. The models were implemented and tested in experiments which showed that neural networks (NN) are highly effective in detecting 5 types of AE (BAE, EAE, LFM, RSAE, TAE) using high resolution ECE. To estimate the neutron deficit, a neural network has been trained that outputs the classical neutron rate using similar inputs to NUBEAM. Also a preliminary ML-based proportional control has been designed and gone through initial testing in experiment to use feedback-control on the neutral beam power to achieve desired amplitude of AE modes and neutron deficits. The effect of AEs on fast-ion confinement is measured by analysing the gap in classical neutron rate from the proposed NN-based NUBEAM and the measured neutron rate.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141826358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temperature-dependent electron-phonon coupling changes the damage cascades in neutron-irradiation molecular dynamics simulation in W 温度依赖性电子-声子耦合改变了 W 中子辐照分子动力学模拟中的损伤级联

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-18 DOI: 10.1088/1741-4326/ad64e7

Younggak Shin, Keonwook Kang, Byeongchan Lee

引用次数: 0

Isotope effects and Alfvén eigenmode stability in JET H, D, T, DT, and He plasmas JET H、D、T、DT 和 He 等离子体中的同位素效应和阿尔芬特征模式稳定性

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-17 DOI: 10.1088/1741-4326/ad6013

R.A. Tinguely, P.G. Puglia, S. Dowson, M. Porkolab, D. Douai, A. Fasoli, L. Frassinetti, D. King, P. Schneider and JET Contributors

{"title":"Isotope effects and Alfvén eigenmode stability in JET H, D, T, DT, and He plasmas","authors":"R.A. Tinguely, P.G. Puglia, S. Dowson, M. Porkolab, D. Douai, A. Fasoli, L. Frassinetti, D. King, P. Schneider and JET Contributors","doi":"10.1088/1741-4326/ad6013","DOIUrl":"https://doi.org/10.1088/1741-4326/ad6013","url":null,"abstract":"While much about Alfvén eigenmode (AE) stability has been explored in previous and current tokamaks, open questions remain for future burning plasma experiments, especially regarding exact stability threshold conditions and related isotope effects; the latter, of course, requiring good knowledge of the plasma ion composition. In the JET tokamak, eight in-vessel antennas actively excite stable AEs, from which their frequencies, toroidal mode numbers, and net damping rates are assessed. The effective ion mass can also be inferred using measurements of the plasma density and magnetic geometry. Thousands of AE stability measurements have been collected by the Alfvén Eigenmode Active Diagnostic in hundreds of JET plasmas during the recent Hydrogen, Deuterium, Tritium, DT, and Helium-4 campaigns. In this novel AE stability database, spanning all four main ion species, damping is observed to decrease with increasing Hydrogenic mass, but increase for Helium, a trend consistent with radiative damping as the dominant damping mechanism. These data are important for confident predictions of AE stability in both non-nuclear (H/He) and nuclear (D/T) operations in future devices. In particular, if radiative damping plays a significant role in overall stability, some AEs could be more easily destabilized in D/T plasmas than their H/He reference pulses, even before considering fast ion and alpha particle drive. Active MHD spectroscopy is also employed on select HD, HT, and DT plasmas to infer the effective ion mass, thereby closing the loop on isotope analysis and demonstrating a complementary method to typical diagnosis of the isotope ratio.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0