Nuclear Fusion最新文献_第7页

Cluster dynamics modeling of hydrogen retention and desorption in tungsten with saturation and multi-trapping effect of sinks 具有饱和和多捕集效应的钨中氢保留和解吸的簇动力学模型

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-08-11 DOI: 10.1088/1741-4326/ad6913

Xiaoru Chen, Yuanyuan Zhang, Liuming Wei, Qirong Zheng, Chuanguo Zhang and Yonggang Li

{"title":"Cluster dynamics modeling of hydrogen retention and desorption in tungsten with saturation and multi-trapping effect of sinks","authors":"Xiaoru Chen, Yuanyuan Zhang, Liuming Wei, Qirong Zheng, Chuanguo Zhang and Yonggang Li","doi":"10.1088/1741-4326/ad6913","DOIUrl":"https://doi.org/10.1088/1741-4326/ad6913","url":null,"abstract":"Hydrogen (H) retention and desorption in tungsten (W)-based plasma-facing materials are still not well understood, largely due to the limitations of ex-situ observations in experimental detection methods like thermal desorption spectroscopy (TDS). In order to reveal the fundamental mechanisms behind H retention and desorption, we developed a cluster dynamics model, IRadMat-TDS, for theoretical modeling of depth distribution and TDS of deuterium (D) in polycrystalline W. The model newly includes the saturated absorption and emission of D in inherent sinks like grain boundaries (GBs), as well as the multi-trapping effect of D in various types of GBs with different trapping energies. The simulated TDS spectra are in agreement with experimental ones. For polycrystalline W under D ion irradiation within keV-energy range, two typical thermal desorption peaks in TDS at around 490 and 550 K are explicitly attributed to D emission from GBs and vacancies, respectively. And GBs play a major role in D retention. Moreover, the broad peaks in TDS come from the convolution of multi-trapping of D in sinks with different types of trapping sites rather than a single-site approximation.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945545","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

Global gyrokinetic analysis of Wendelstein 7-X discharge: unveiling the importance of trapped-electron-mode and electron-temperature-gradient turbulence 温德斯坦 7-X 放电的全局陀螺动力学分析：揭示困电子模式和电子温度梯度湍流的重要性

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-08-11 DOI: 10.1088/1741-4326/ad6675

Felix Wilms, Alejandro Bañón Navarro, Thomas Windisch, Sergey Bozhenkov, Felix Warmer, Golo Fuchert, Oliver Ford, Daihong Zhang, Torsten Stange, Frank Jenko and the W7-X Team

引用次数: 0

Fast nonlinear scattering of runaway electron beams through resonant interactions with plasma waves 通过与等离子体波的共振相互作用实现失控电子束的快速非线性散射

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-08-08 DOI: 10.1088/1741-4326/ad6ce6

Hye Lin Kang, Young Dae Yoon, Myeonghun Cho, Gunsu S. Yun

引用次数: 0

Validation of a synthetic fast ion loss detector model for Wendelstein 7-X 温德斯坦 7-X 合成快速离子损耗探测器模型的验证

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-08-07 DOI: 10.1088/1741-4326/ad6885

A. LeViness, S.A. Lazerson, A. Jansen van Vuuren, J. Rueda-Rueda, M. Beurskens, S. Bozhenkov, K.J. Brunner, O.P. Ford, G. Fuchert, M. Garcìa-Muñoz, M. Isobe, C. Killer, J. Knauer, K. Ogawa, N. Pablant, E. Pasch, P. Poloskei, T. Romba and the W7-X Team

{"title":"Validation of a synthetic fast ion loss detector model for Wendelstein 7-X","authors":"A. LeViness, S.A. Lazerson, A. Jansen van Vuuren, J. Rueda-Rueda, M. Beurskens, S. Bozhenkov, K.J. Brunner, O.P. Ford, G. Fuchert, M. Garcìa-Muñoz, M. Isobe, C. Killer, J. Knauer, K. Ogawa, N. Pablant, E. Pasch, P. Poloskei, T. Romba and the W7-X Team","doi":"10.1088/1741-4326/ad6885","DOIUrl":"https://doi.org/10.1088/1741-4326/ad6885","url":null,"abstract":"We present the first validated synthetic diagnostic for fast ion loss detectors (FILDs) in the Wendelstein 7-X (W7-X) stellarator. This model has been developed on, and validated against experimental data from, a FILD provided by the National Institute for Fusion Science (NIFS-FILD), with potential future applicability to the existing Faraday Cup FILD (FC-FILD) on W7-X as well as the scintillating FILD (S-FILD) currently under development. A workflow combining Monte Carlo codes BEAMS3D and ASCOT5 is used to track fast ions produced by neutral beam injection from the moment of ionization until they are thermalized or lost from the last closed flux surface, and from there to a virtual plane which serves as a projection of the entrance aperture to the FILD. Simulations in ASCOT5 are analyzed via a geometric method to determine the probability of transmission through the FILD aperture and onto the detector as a function of normalized momentum, pitch angle, gyrophase, and position at the virtual plane. This probability is then applied to the simulated ions arriving from the plasma, producing a simulated signal from a computationally tractable number of simulated fast ions. Simulated signals are presented for two W7-X experiments with neutral beam injection and quantitatively compared with experimental measurements from the NIFS-FILD diagnostic. An estimate of the frequency of charge-exchange with neutral particles in the edge is performed, and it is found that this process may have a significant impact on the measured signals.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945548","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

Deconfinement of runaway electrons by local vertical magnetic field perturbation 局部垂直磁场扰动对失控电子的解约束作用

IF 3.3 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-08-01 DOI: 10.1088/1741-4326/ad5a1e

Someswar Dutta, Deepti Sharma, R.L. Tanna, J. Ghosh and D. Raju

{"title":"Deconfinement of runaway electrons by local vertical magnetic field perturbation","authors":"Someswar Dutta, Deepti Sharma, R.L. Tanna, J. Ghosh and D. Raju","doi":"10.1088/1741-4326/ad5a1e","DOIUrl":"https://doi.org/10.1088/1741-4326/ad5a1e","url":null,"abstract":"Runaway electron (RE) deconfinement and subsequent suppression is of prime importance for successful long-term operation of any tokamak. In this work, to deconfine and mitigate REs, the efficacy of local vertical field (LVF) perturbation has been explored numerically. LVF perturbation-assisted RE loss studies are carried out by simulating the drift orbits of the REs in magnetostatic perturbed fields and estimating the resulting orbit losses for different initial energies and magnitudes of LVF perturbation. To this end, the pre-existing PARTICLE code has been extended to the relativistic full-orbit-following code PARTICLE-3D (P3D) integrated with the magnetic field calculation code EFFI and plasma equilibrium field calculation code IPREQ to include the required fields for studying particle dynamics in general; this is then used to numerically model LVF perturbation-assisted RE deconfinement experiments conducted in the ADITYA tokamak. Simulation results show a significant (∼90%) deconfinement of REs with the application of LVF perturbation of a suitable amplitude (∼0.1% of the total magnetic field) in a preferred direction. The existence of a threshold magnitude of the applied field is also established, which is observed to be dependent on the energy of the REs. The simulation results reproduce all the experimental observations and reveal other interesting features of RE mitigation using LVF perturbation. The temporal map of orbiting time of REs shows that REs originating from the inboard side edge region ( N > 0.5) of the plasma are relatively more prone to be lost with the application of suitable LVF perturbation than those originating from the plasma core. Interestingly, the simulation results demonstrate the existence of strong correlation between the safety factor (q) profile in the plasma edge region ( N > 0.7) and the level of RE deconfinement using LVF perturbation.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885827","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

Automated shot-to-shot optimization of the plasma start-up scenario in the TCV tokamak TCV 托卡马克中等离子体启动方案的自动逐次优化

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-26 DOI: 10.1088/1741-4326/ad67ee

L. E. di Grazia, Federico Felici, M. Mattei, A. Merle, Pedro Molina Cabrera, C. Galperti, S. Coda, B. P. Duval, Antoine Maier, A. Mele, A. Perek, A. Pironti, T. Ravensbergen, Benjamin Vincent, C. Wüthrich

{"title":"Automated shot-to-shot optimization of the plasma start-up scenario in the TCV tokamak","authors":"L. E. di Grazia, Federico Felici, M. Mattei, A. Merle, Pedro Molina Cabrera, C. Galperti, S. Coda, B. P. Duval, Antoine Maier, A. Mele, A. Perek, A. Pironti, T. Ravensbergen, Benjamin Vincent, C. Wüthrich","doi":"10.1088/1741-4326/ad67ee","DOIUrl":"https://doi.org/10.1088/1741-4326/ad67ee","url":null,"abstract":"\u0000 Plasma start-up concerns the initial formation of a tokamak plasma by obtaining breakdown at a desired time and location, burnthrough of impurities until a fully ionized plasma is obtained, while ramping up the plasma current following a desired trajectory and maintaining the plasma at the desired location in the vacuum vessel. This is typically achieved manipulating poloidal magnetic fields, gas injection and possibly auxiliary heating. Model-based design techniques for plasma start-up have been gaining increasing attention in view of future large tokamaks which have more stringent constraints and less room for trial-and-error. In this paper, we formulate the tokamak start-up scenario design problem as a constrained optimization problem using a relatively simple electromagnetic model of the formation phase, neglecting details of the breakdown and burnthrough physics. We also introduce a novel shot-to-shot correction algorithm, based on the Iterative Learning Control concept, to compensate for unavoidable modeling errors based on experimental data. The effectiveness of the approach is demonstrated in experiments on the TCV tokamak showing that the target ramp-up scenario could be obtained in a small number of shots.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798695","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

Interpretive modeling of tungsten divertor leakage during experiments with neon gas seeding 氖气种子实验中钨分流器泄漏的解释性建模

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-26 DOI: 10.1088/1741-4326/ad67f0

M. Parsons, G. Sinclair, T. Abrams, Patrick Byrne, C. Chrystal, F. Effenberg, J. Herfindal, T. Odstrcil, R. Wilcox

{"title":"Interpretive modeling of tungsten divertor leakage during experiments with neon gas seeding","authors":"M. Parsons, G. Sinclair, T. Abrams, Patrick Byrne, C. Chrystal, F. Effenberg, J. Herfindal, T. Odstrcil, R. Wilcox","doi":"10.1088/1741-4326/ad67f0","DOIUrl":"https://doi.org/10.1088/1741-4326/ad67f0","url":null,"abstract":"\u0000 Many existing and future tokamaks with tungsten divertors operate, or will operate, with low-Z impurity seeding, but the direct effect of these seeded impurities on tungsten Scrape-off-Layer (SOL) transport has not been explored in detail. This paper reports on a DIII-D experiment designed to test how tungsten divertor leakage from the Small- Angle Slot V-Shaped, tungsten-coated divertor is impacted by neon seeding at a variety of injection rates and poloidal injection locations. Measurements from the experiment show an inverse relationship between the neon injection rate and the tungsten core penetration factor. Interpretive modeling is performed with a combination of the SOLPS-ITER and DIVIMP codes to assess the underlying tungsten behavior. The modeling results show that the reduction in tungsten divertor leakage is driven by both an increase in the divertor collisionality as well as a reduction in the ion temperature gradient near the divertor target. Collisions between low-Z impurities and tungsten impurities are found to have a significant impact on the tungsten SOL transport, such that ignoring the low-Z impurity collisional effects on the tungsten transport can result in an overestimate of the divertor leakage by an order-of-magnitude. Given the importance of these localized interactions, neon seeding from the closed, slot-like divertor has a clear advantage in being able to reduce tungsten divertor leakage without the high levels of neon core contamination that occur when seeding from other poloidal locations.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800762","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

Exploring the suppression methods of helium-induced damages in tungsten by investigating the interaction between beryllium and helium 通过研究铍和氦之间的相互作用探索钨中氦诱发损伤的抑制方法

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-26 DOI: 10.1088/1741-4326/ad67f1

Hong-Bo Zhou, Jin-Liang Li, Chaoxiang Lin, Ya-Xin Zhai, Zhangcan Yang, Yu-Hao Li, Yudi Niu, Huilei Ma, Guang-Hong Lu

{"title":"Exploring the suppression methods of helium-induced damages in tungsten by investigating the interaction between beryllium and helium","authors":"Hong-Bo Zhou, Jin-Liang Li, Chaoxiang Lin, Ya-Xin Zhai, Zhangcan Yang, Yu-Hao Li, Yudi Niu, Huilei Ma, Guang-Hong Lu","doi":"10.1088/1741-4326/ad67f1","DOIUrl":"https://doi.org/10.1088/1741-4326/ad67f1","url":null,"abstract":"\u0000 Helium (He)-induced damages are sensitive concerns for the performance of tungsten plasma facing materials (W-PFMs). Recent experiments have revealed that trace impurities in He plasma can effectively prevent the formation of He bubbles and fuzz on W surfaces. To explore its plausibility and underlying mechanism, we performed a multiscale computational study that combines density functional theory calculations and object kinetic Monte Carlo simulations to investigate the effects of a small quantity of beryllium (Be) on the evolution of He bubbles. It is found that there is strong attractive interaction between He and Be, which can be attributed to the decrease of electron density and the lattice distortion induced by embedded Be atom. Therefore, the co-implantation of Be continuously introduces trapping centers for He. Due to low implantation depth and high migration energy of Be, the Be atoms are located close to the surface, leading to the trapping of the majority of He within the near-surface region and the development of a shielding layer for He permeation. The presence of Be facilitates the dispersion of the trapped He, skewing the He clusters into smaller size. More importantly, the Be trapping centers bring the He clusters closer to the surface, significantly increasing the probability of bubble bursting and the release of He back to the vacuum. These ultimately leads to a lower retention of He in the case of He+Be co-irradiation, compared with the case of He-only irradiation. Consequently, our findings elucidate the suppressive effect of a low flux of Be atoms on the growth of He bubbles, highlighting the need to focus on the synergetic effects between plasma species.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799471","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

Counteracting sawtooth crash effects via fluctuation-induced inward transport in HL-2A NBI plasma 通过 HL-2A NBI 血浆中波动诱导的内向转运抵消锯齿碰撞效应

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-26 DOI: 10.1088/1741-4326/ad67f2

Jie Wu, Tao Lan, Weixing Ding, Jiaren Wu, Min Xu, Lin Nie, Wei Chen, Min Jiang, Zhihui Huang, K. Yi, Na Wu, Weice Wang, Q. Zou, T. Long, B. Yuan, Liming Yu, Yi Yu, R. Ke, Hangqi Xu, Pengcheng Lu, Tianxiong Wang, Qi Dong, Yongkang Zhou, Hu Cai, Peng Deng, Xingkang Wang, Zeqi Bai, Yuhua Huang, Chen Chen, W. Mao, Chu Zhou, Ah Di Liu, Zhengwei Wu, Jinlin Xie, Wulyu Zhong, Xuru Duan, Wandong Liu, Zhuang Ge

{"title":"Counteracting sawtooth crash effects via fluctuation-induced inward transport in HL-2A NBI plasma","authors":"Jie Wu, Tao Lan, Weixing Ding, Jiaren Wu, Min Xu, Lin Nie, Wei Chen, Min Jiang, Zhihui Huang, K. Yi, Na Wu, Weice Wang, Q. Zou, T. Long, B. Yuan, Liming Yu, Yi Yu, R. Ke, Hangqi Xu, Pengcheng Lu, Tianxiong Wang, Qi Dong, Yongkang Zhou, Hu Cai, Peng Deng, Xingkang Wang, Zeqi Bai, Yuhua Huang, Chen Chen, W. Mao, Chu Zhou, Ah Di Liu, Zhengwei Wu, Jinlin Xie, Wulyu Zhong, Xuru Duan, Wandong Liu, Zhuang Ge","doi":"10.1088/1741-4326/ad67f2","DOIUrl":"https://doi.org/10.1088/1741-4326/ad67f2","url":null,"abstract":"\u0000 The Langmuir probe observed an increase in density and floating potential fluctuations after the sawtooth crash at the edge of HL-2A neutral beam injection heated plasma. This process initiates fluctuating-induced radial inward particle transport once the plasma enters a period with strong sawtooth crash. The inward transport comprises broad-band fluctuations with varying scales, which occur uniquely in the immediate aftermath of the sawtooth crash-driven outflow, signifying a transient phenomenon confined to that specific interval. These results demonstrate that the sawtooth crash can significantly impact edge turbulence by modifying electrostatic fluctuations. This modification changes the direction of electric fluctuation-induced particle transport, thereby reducing the influence of the intense sawtooth crash-driven outflow. Furthermore, the observations support the existence of a damping mechanism for the outflow during the formation of inward flux after the sawtooth crash, which may be associated with the recovery process of sawtooth cycle.","PeriodicalId":19379,"journal":{"name":"Nuclear Fusion","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800117","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

Density profiles in stellarators: An overview of particle transport, fueling and profile shaping studies at TJ-II 恒星器中的密度曲线：TJ-II粒子传输、燃料和剖面塑造研究综述

IF 3.5 1区物理与天体物理

Nuclear Fusion Pub Date : 2024-07-26 DOI: 10.1088/1741-4326/ad67ef

Arturo Alonso, Daniel Alegre, Javier Alonso, R. Anton, Ana Arias-Camisón, E. Ascasíbar, A. Baciero, J. Barcala, M. Barnes, Emilio Blanco, Luis Alberto Bueno, Andrés Bustos, Santiago Cabrera, E. de la Cal, Ivan Calvo, A. Cappa, D. Carralero, Ricardo Carrasco, Benjamin A Carreras, Rodrigo Castro, Alfonso de Castro, Luis Alfonso Cebrián, Manuel Chamorro, A. Chmyga, Pablo Colino, Javier Duque

引用次数: 1