arXiv - PHYS - Plasma Physics最新文献

Oscillation damper for misaligned witness in plasma wakefield accelerator 等离子体汪场加速器中错位证人的振荡阻尼器

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-18 DOI: arxiv-2409.12041

K. V. Lotov, I. Yu. Kargapolov, P. V. Tuev

引用次数: 0

Semantic Information Management in Low-Temperature Plasma Science and Technology with VIVO 利用 VIVO 实现低温等离子体科学与技术中的语义信息管理

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11065

Ihda Chaerony Siffa, Robert Wagner, Laura Vilardell Scholten, Markus M. Becker

{"title":"Semantic Information Management in Low-Temperature Plasma Science and Technology with VIVO","authors":"Ihda Chaerony Siffa, Robert Wagner, Laura Vilardell Scholten, Markus M. Becker","doi":"arxiv-2409.11065","DOIUrl":"https://doi.org/arxiv-2409.11065","url":null,"abstract":"Digital research data management is increasingly integrated across\u0000universities and research institutions, addressing the handling of research\u0000data throughout its lifecycle according to the FAIR data principles (Findable,\u0000Accessible, Interoperable, Reusable). Recent emphasis on the semantic and\u0000interlinking aspects of research data, e.g., by using ontologies and knowledge\u0000graphs further enhances findability and reusability. This work presents a\u0000framework for creating and maintaining a knowledge graph specifically for\u0000low-temperature plasma (LTP) science and technology. The framework leverages a\u0000domain-specific ontology called Plasma-O, along with the VIVO software as a\u0000platform for semantic information management in LTP research. While some\u0000research fields are already prepared to use ontologies and knowledge graphs for\u0000information management, their application in LTP research is nascent. This work\u0000aims to bridge this gap by providing a framework that not only improves\u0000research data management but also fosters community participation in building\u0000the domain-specific ontology and knowledge graph based on the published\u0000materials. The results may also support other research fields in the practical\u0000use of knowledge graphs for semantic information management.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Extended Variational Method for the Resistive Wall Mode in Toroidal Plasma Confinement Devices 环形等离子体约束装置中电阻壁模式的扩展变量法

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11298

R. Fitzpatrick

{"title":"An Extended Variational Method for the Resistive Wall Mode in Toroidal Plasma Confinement Devices","authors":"R. Fitzpatrick","doi":"arxiv-2409.11298","DOIUrl":"https://doi.org/arxiv-2409.11298","url":null,"abstract":"The external-kink stability of a toroidal plasma surrounded by a rigid\u0000resistive wall is investigated. The well-known analysis of Haney & Freidberg is\u0000rigorously extended to allow for a wall that is sufficiently thick that the\u0000thin-shell approximation does not necessarily hold. A generalized\u0000Haney-Freidberg formula for the growth-rate of the resistive wall mode is\u0000obtained. Thick-wall effects do not change the marginal stability point of the\u0000mode, but introduce an interesting asymmetry between growing and decaying\u0000modes. Growing modes have growth-rates that exceed those predicted by the\u0000original Haney-Freidberg formula. On the other hand, decaying modes have\u0000decay-rates that are less than those predicted by the original formula. The well-known Hu-Betti formula for the rotational stabilization of the\u0000resistive wall mode is also generalized to take thick-wall effects into\u0000account. Increasing wall thickness facilitates the rotational stabilization of\u0000the mode, because it decreases the critical toroidal electromagnetic torque\u0000that the wall must exert on the plasma. On the other hand, the real frequency\u0000of the mode at the marginal stability point increases with increasing wall\u0000thickness.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Limitations from charge quantization on the parallel temperature diagnostic of nonneutral plasmas 电荷量子化对非中性等离子体平行温度诊断的限制

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11610

Adrianne Zhong, Joel Fajans, Jonathan S. Wurtele

引用次数: 0

Turbulence and transport in mirror geometries in the Large Plasma Device 大型等离子体装置中镜面几何形状的湍流和传输

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11557

Phil Travis, Troy Carter

{"title":"Turbulence and transport in mirror geometries in the Large Plasma Device","authors":"Phil Travis, Troy Carter","doi":"arxiv-2409.11557","DOIUrl":"https://doi.org/arxiv-2409.11557","url":null,"abstract":"Thanks to advances in plasma science and enabling technology, mirror machines\u0000are being reconsidered for fusion power plants and as possible fusion\u0000volumetric neutron sources. However cross-field transport and turbulence in\u0000mirrors remains relatively understudied compared to toroidal devices.\u0000Turbulence and transport in mirror configurations were studied utilizing the\u0000flexible magnetic geometry of the Large Plasma Device (LAPD). Multiple mirror\u0000ratios from $ M = 1 $ to $ M = 2.68 $ and three mirror-cell lengths from $L =\u00003.51 $m to $ L = 10.86 $m were examined. Langmuir and magnetic probes were used\u0000to measure profiles of density, temperature, potential, and magnetic field. The\u0000fluctuation-driven $ tilde{ E } times B $ particle flux was calculated from\u0000these quantities. Two probe correlation techniques were used to infer\u0000wavenumbers and two-dimensional structure. Cross-field particle flux and\u0000density fluctuation power decreased with increased mirror ratio. Core density\u0000and temperatures remain similar with mirror ratio, but radial line-integrated\u0000density increased. The physical expansion of the plasma in the mirror cell by\u0000using a higher field in the source region may have led to reduced density\u0000fluctuation power through the increased gradient scale length. This increased\u0000scale length reduced the growth rate and saturation level of rotational\u0000interchange and drift-like instabilities. Despite the introduction of magnetic\u0000curvature, no evidence of mirror driven instabilities -- interchange, velocity\u0000space, or otherwise -- were observed. For curvature-induced interchange, many\u0000possible stabilization mechanisms were present, suppressing the visibility of\u0000the instability.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wave Steepening and Shock Formation in Ultracold Neutral Plasmas 超冷中性等离子体中的波陡化和冲击形成

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11319

M. K. Warrens, N. P. Inman, G. M. Gorman, B. T. Husick, S. J. Bradshaw, T. C. Killian

引用次数: 0

Escape of fast radio bursts from magnetars 磁星快速射电暴的逃逸

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-16 DOI: arxiv-2409.10732

Emanuele Sobacchi, Masanori Iwamoto, Lorenzo Sironi, Tsvi Piran

{"title":"Escape of fast radio bursts from magnetars","authors":"Emanuele Sobacchi, Masanori Iwamoto, Lorenzo Sironi, Tsvi Piran","doi":"arxiv-2409.10732","DOIUrl":"https://doi.org/arxiv-2409.10732","url":null,"abstract":"Fast radio bursts (FRBs) are bright extragalactic transients likely produced\u0000by magnetars. We study the propagation of FRBs in magnetar winds, assuming that\u0000the wind is strongly magnetized and composed of electron-positron pairs. We\u0000focus on the regime where the strength parameter of the radio wave, $a_0$, is\u0000larger than unity, and the wave frequency, $omega_0$, is larger than the\u0000Larmor frequency in the background magnetic field, $omega_{rm L}$. We show\u0000that strong radio waves with $a_0>1$ are able to propagate when $omega_0 >\u0000a_0omega_{rm L}$, as the plasma current is a linear function of the wave\u0000electric field. The dispersion relation is independent of the wave strength\u0000parameter when $omega_0 > a_0omega_{rm L}$. Instead, radio waves could be\u0000damped when $omega_0 < a_0omega_{rm L}$, as a significant fraction of the\u0000wave energy is used to compress the plasma and amplify the background magnetic\u0000field. Our results suggest that FRBs should be produced at large distances from\u0000the magnetar (i.e., $R>10^{12}{rm; cm}$, where the condition $omega_0 >\u0000a_0omega_{rm L}$ is satisfied). Alternatively, the structure of the magnetar\u0000wind should be strongly modified during a flare to allow the escape of FRBs\u0000produced at radii $R<10^{12}{rm; cm}$.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Excess entropy of strongly coupled Yukawa fluids 强耦合汤川流体的过熵

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-16 DOI: arxiv-2409.10645

Sergey Khrapak

{"title":"Excess entropy of strongly coupled Yukawa fluids","authors":"Sergey Khrapak","doi":"arxiv-2409.10645","DOIUrl":"https://doi.org/arxiv-2409.10645","url":null,"abstract":"The entropy of strongly coupled Yukawa fluids is discussed from several\u0000perspectives. First, it is demonstrated that a vibrational paradigm of atomic\u0000dynamics in dense fluids can be used to obtain a simple and accurate estimate\u0000of the entropy without any adjustable parameters. Second, it is explained why a\u0000quasiuniversal value of the excess entropy of simple fluids at the freezing\u0000point should be expected, and it is demonstrated that a remaining very weak\u0000dependence of the freezing point entropy on the screening parameter in the\u0000Yukawa fluid can be described by a simple linear function. Third, a scaling of\u0000the excess entropy with the freezing temperature is examined, a modified form\u0000of the Rosenfeld-Tarazona scaling is put forward, and some consequences are\u0000briefly discussed. Fourth, the location of the Frenkel line on the phase\u0000diagram of Yukawa systems is discussed in terms of the excess entropy and\u0000compared with some predictions made in the literature. Fifth, the excess\u0000entropy scaling of the transport coefficients (self-diffusion, viscosity, and\u0000thermal conductivity) is reexamined using the contemporary datasets for the\u0000transport properties of Yukawa fluids. The results could be of particular\u0000interest in the context of complex (dusty) plasmas, colloidal suspensions,\u0000electrolytes, and other related systems with soft pairwise interactions.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-Fidelity Data-Driven Dynamics Model for Reinforcement Learning-based Magnetic Control in HL-3 Tokamak 基于强化学习的 HL-3 托卡马克磁控制的高保真数据驱动动力学模型

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-14 DOI: arxiv-2409.09238

Niannian Wu, Zongyu Yang, Rongpeng Li, Ning Wei, Yihang Chen, Qianyun Dong, Jiyuan Li, Guohui Zheng, Xinwen Gong, Feng Gao, Bo Li, Min Xu, Zhifeng Zhao, Wulyu Zhong

{"title":"High-Fidelity Data-Driven Dynamics Model for Reinforcement Learning-based Magnetic Control in HL-3 Tokamak","authors":"Niannian Wu, Zongyu Yang, Rongpeng Li, Ning Wei, Yihang Chen, Qianyun Dong, Jiyuan Li, Guohui Zheng, Xinwen Gong, Feng Gao, Bo Li, Min Xu, Zhifeng Zhao, Wulyu Zhong","doi":"arxiv-2409.09238","DOIUrl":"https://doi.org/arxiv-2409.09238","url":null,"abstract":"The drive to control tokamaks, a prominent technology in nuclear fusion, is\u0000essential due to its potential to provide a virtually unlimited source of clean\u0000energy. Reinforcement learning (RL) promises improved flexibility to manage the\u0000intricate and non-linear dynamics of the plasma encapsulated in a tokamak.\u0000However, RL typically requires substantial interaction with a simulator capable\u0000of accurately evolving the high-dimensional plasma state. Compared to\u0000first-principle-based simulators, whose intense computations lead to sluggish\u0000RL training, we devise an effective method to acquire a fully data-driven\u0000simulator, by mitigating the arising compounding error issue due to the\u0000underlying autoregressive nature. With high accuracy and appealing\u0000extrapolation capability, this high-fidelity dynamics model subsequently\u0000enables the rapid training of a qualified RL agent to directly generate\u0000engineering-reasonable magnetic coil commands, aiming at the desired long-term\u0000targets of plasma current and last closed flux surface. Together with a\u0000surrogate magnetic equilibrium reconstruction model EFITNN, the RL agent\u0000successfully maintains a $100$-ms, $1$ kHz trajectory control with accurate\u0000waveform tracking on the HL-3 tokamak. Furthermore, it also demonstrates the\u0000feasibility of zero-shot adaptation to changed triangularity targets,\u0000confirming the robustness of the developed data-driven dynamics model. Our work\u0000underscores the advantage of fully data-driven dynamics models in yielding\u0000RL-based trajectory control policies at a sufficiently fast pace, an\u0000anticipated engineering requirement in daily discharge practices for the\u0000upcoming ITER device.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Real-time observation of frustrated ultrafast recovery from ionisation in nanostructured SiO2 using laser driven accelerators 利用激光驱动加速器实时观测纳米结构二氧化硅电离后的受挫超快恢复情况

arXiv - PHYS - Plasma Physics Pub Date : 2024-09-13 DOI: arxiv-2409.08689

J. P. Kennedy, M. Coughlan, C. R. J. Fitzpatrick, H. M. Huddleston, J. Smyth, N. Breslin, H. Donnelly, C. Arthur, B. Villagomez, O. N. Rosmej, F. Currell, L. Stella, D. Riley, M. Zepf, M. Yeung, C. L. S. Lewis, B. Dromey

{"title":"Real-time observation of frustrated ultrafast recovery from ionisation in nanostructured SiO2 using laser driven accelerators","authors":"J. P. Kennedy, M. Coughlan, C. R. J. Fitzpatrick, H. M. Huddleston, J. Smyth, N. Breslin, H. Donnelly, C. Arthur, B. Villagomez, O. N. Rosmej, F. Currell, L. Stella, D. Riley, M. Zepf, M. Yeung, C. L. S. Lewis, B. Dromey","doi":"arxiv-2409.08689","DOIUrl":"https://doi.org/arxiv-2409.08689","url":null,"abstract":"Ionising radiation interactions in matter can trigger a cascade of processes\u0000that underpin long-lived damage in the medium. To date, however, a lack of\u0000suitable methodologies has precluded our ability to understand the role that\u0000material nanostructure plays in this cascade. Here, we use transient\u0000photoabsorption to track the lifetime of free electrons (t_c) in bulk and\u0000nanostructured SiO2 (aerogel) irradiated by picosecond-scale (10^-12 s) bursts\u0000of X-rays and protons from a laser-driven accelerator. Optical streaking\u0000reveals a sharp increase in t_c from < 1 ps to > 50 ps over a narrow average\u0000density (p_av) range spanning the expected phonon-fracton crossover in\u0000aerogels. Numerical modelling suggests that this discontinuity can be\u0000understood by a quenching of rapid, phonon-assisted recovery in irradiated\u0000nanostructured SiO_2. This is shown to lead to an extended period of enhanced\u0000energy density in the excited electron population. Overall, these results open\u0000a direct route to tracking how low-level processes in complex systems can\u0000underpin macroscopically observed phenomena and, importantly, the conditions\u0000that permit them to emerge.","PeriodicalId":501274,"journal":{"name":"arXiv - PHYS - Plasma Physics","volume":"213 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0