Article
Physics, Fluids & Plasmas
Eun-jin Kim, Rainer Hollerbach
Summary: We investigate the time-varying turbulence statistical properties of edge-localized modes (ELMs) in fusion plasmas using a simplified stochastic model. The study analyzes the effects of different values of stochastic noise and varying forms of input power on ELM dynamics. Among the statistical quantities, the path-dependent information geometry is shown to be a robust diagnostic tool for quantifying hysteresis, self-regulation, and early detection of subtle changes in ELM dynamics.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
M. Yu Isaev, V. M. Leonov, S. Yu Medvedev
Summary: This study focuses on the stability of Alfven eigenmodes in a plasma with negative magnetic shear excited by fast particles, comparing scenarios in T-15MD and TRT tokamaks. The analysis involves calculations of various AE properties, such as spatial structures, frequencies, Landau damping, growth rates, nonlinear evolution, and effects on particle losses. Additionally, the non-monotonic profile of the safety factor due to auxiliary ECR heating offers new possibilities for exciting modes on multiple magnetic surfaces in TRT tokamak.
PLASMA PHYSICS REPORTS
(2021)
Review
Physics, Fluids & Plasmas
Clemente Angioni
Summary: This paper reviews the theory of collisional and turbulent transport of impurities in tokamak plasmas, aiming to provide a historical reconstruction of scientific progress and a complete description of current theoretical knowledge. The article presents a comprehensive overview of transport mechanisms and comparisons between theoretical predictions and experimental observations, highlighting the impact of validation activities on motivating further theoretical investigations. It also discusses the direct interactions between collisional and turbulent transport, as well as the progress in theory-based modelling activities.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Physics, Multidisciplinary
Hong-bo Cai, Xin-xin Yan, Pei-lin Yao, Shao-ping Zhu
Summary: This study presents a new framework to simulate shock waves and hydrodynamic instabilities in high-density plasmas, with ions modeled using particle-in-cell method and electrons as a massless fluid. It investigates turbulent mixing between light and heavy plasmas initiated by shock waves, revealing the role of self-generated electromagnetic fields in late-time plasma mixing. The proposed method is able to describe shock-driven hydrodynamic instabilities involving mixing and electromagnetic fields at the interface in plasma.
MATTER AND RADIATION AT EXTREMES
(2021)
Article
Mathematics
Yuri V. Mitrishkin, Pavel S. Korenev, Artem E. Konkov, Valerii I. Kruzhkov, Nicolai E. Ovsiannikov
Summary: This paper deals with the identification methods of plasma equilibrium reconstruction in D-shaped tokamaks based on plasma external magnetic measurements. The novel approach combines an offline equilibrium reconstruction algorithm and new identification methods to improve the speed of response. The algorithm first applies Picard iterations to the plasma discharge data to obtain gaps between the plasma boundary and the first wall, and then applies new identification methods to these gap values, producing real-time plasma shape models. The results of simulation using experimental data from the Globus-M2 tokamak demonstrate the effectiveness of the proposed identification systems.
Article
Mathematics
Vladimir D. Pustovitov, Nikolay V. Chukashev
Summary: This article considers the dynamic problem of plasma equilibrium in a tokamak, with a focus on the electromagnetic reaction of the vacuum vessel resistive wall. The induced currents in the wall affect the external magnetic field, which in turn determines the plasma shape and position. The simultaneous consideration of these factors presents a challenge in the description.
Article
Nanoscience & Nanotechnology
Guangzhi Ren, Lai Wei, Fang Yu, Zheng-Xiong Wang, Jiquan Li
Summary: Comprehensive eigenmode characterizations of ion-temperature-gradient instabilities in slab geometries with different magnetic shear profiles were investigated using an eigenvalue method. It was found that in the configuration with negative magnetic shear, high-order-l modes can be stabilized.
Review
Chemistry, Applied
M. Dharini, S. Jaspi, R. Mahendran
Summary: Cold plasma, generated at room temperature, consists of reactive species that cause chemical and physical changes in biological materials. Its applications in food aim to ensure safety, quality, and property modification. However, our understanding of the mechanisms behind these alterations is limited, with only a few reactive oxygen and nitrogen species being extensively studied. This review explores the use of different feed gases to modify species composition and highlights the importance of considering all reactive species in food modification, along with the potential of molecular dynamics simulation to bridge the knowledge gap.
Article
Materials Science, Paper & Wood
Yi Pu, Jing Yang, Stephen J. Russell, Xin Ning
Summary: Cotton based nonwovens with unidirectional water-transport were prepared using atmospheric plasma technology, creating a super-hydrophobic surface on one side and completely wettable surface on the other. This differential moisture management property enables the nonwovens to exhibit unidirectional liquid transport without negatively affecting vapor transmission and air permeability, making it highly desirable for hygiene, infection control and medical device applications.
Article
Physics, Fluids & Plasmas
Y. Bliokh, J. G. Leopold, Ya. E. Krasik
Summary: A one-dimensional model is presented to interpret the specific state of an ensemble of electrons continuously injected into an electrostatic potential well, known as a squeezed state of an electron beam. The spatial distribution of electron number density in this steady-state correlates with the shape of the potential well, and perturbations propagate along the electron cloud in Trivelpiece-Gould modes.
PHYSICS OF PLASMAS
(2021)
Article
Multidisciplinary Sciences
Andrea Gemma, Fatemeh Tabatabaei, Ute Drechsler, Anel Zulji, Herve Dekkiche, Nico Mosso, Thomas Niehaus, Martin R. Bryce, Samy Merabia, Bernd Gotsmann
Summary: By combining the break junction technique with a suspended heat-flux sensor, the researchers measured the total thermal and electrical conductance of a single molecule, at room temperature, along with its Seebeck coefficient. The result is in agreement with predictions and opens new opportunities for thermoelectric applications.
NATURE COMMUNICATIONS
(2023)
Review
Physics, Fluids & Plasmas
S. M. Kaye, J. W. Connor, C. M. Roach
Summary: Spherical tokamaks (STs) exhibit significantly improved normalized confinement with decreasing collisionality compared to higher aspect ratio devices, which is promising for the development of an ST-based fusion pilot plant. The differences in transport properties in STs, such as enhanced toroidicity and E-r x B shearing rates, result in stronger electromagnetic effects and different turbulence modes compared to higher aspect ratio devices.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Nuclear Science & Technology
M. L. Walker
Summary: This article introduces an extended method for more generalized modeling of tokamak PF conductor circuits. The method combines previously existing methods for integrating plasma response and tokamak circuits with a more powerful circuit modeling technique derived from automatic circuit simulation codes. It can be applied to various tokamaks' conductor circuit modeling needs and allows for fast and automated modeling of complex and dynamically changing circuit topologies.
FUSION ENGINEERING AND DESIGN
(2022)
Article
Physics, Fluids & Plasmas
K. C. Shaing, M. Garcia-Munoz, E. Viezzer
Summary: A version of the drift kinetic equation that includes the physics of the nonlinear trapping and quasilinear plateau regimes in tokamaks is used to calculate neoclassical toroidal plasma viscosity in the bounce-transit and drift resonance regimes. It is found that the transition between these two regimes is controlled by a mirror-force like term. The quasilinear regime prevails when the effective collision frequency is larger than the mirroring or the nonlinear bounce frequency, while the nonlinear trapping regime dominates otherwise. The Eulerian approach is used to demonstrate this, which goes beyond the traditional method of integrating along the unperturbed orbit.
Article
Physics, Fluids & Plasmas
Matteo Del Prete, Giovanni Montani
Summary: In this study, the influence of toroidal plasma rotation on tokamak equilibrium quantities was investigated through analytical solutions based on different representations. The introduction of toroidal rotation resulted in variations of relevant plasma quantities, particularly enhancing the poloidal beta. By using polynomial and Bessel function expressions, different plasma scenarios were reproduced with a focus on the shape of the separatrix and the compatibility of configurations with plasma velocity values.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Physics, Fluids & Plasmas
M. Marin, J. Citrin, L. Garzotti, M. Valovic, C. Bourdelle, Y. Camenen, F. J. Casson, A. Ho, F. Koechl, M. Maslov
Summary: The study successfully reproduced the pellet cycle of a multiple-isotope plasma using reduced turbulent transport modeling, emphasizing the importance of accurate pellet cycle modeling in assessing fuel efficiency and burn control. Results showed comparable deuterium penetration time to energy confinement time when deuterium pellets were injected into a hydrogen plasma, with encouraging predictions for reactor fuelling capability and burn control in the presence of negative density gradients following pellet deposition. The study compared the QuaLiKiz reduced turbulence model with GENE linear and nonlinear higher fidelity modeling, with promising results.
Article
Physics, Fluids & Plasmas
K. K. Kirov, E. Belonohy, C. D. Challis, J. Eriksson, D. Frigione, L. Garzotti, L. Giacomelli, J. Hobirk, A. Kappatou, D. Keeling, D. King, E. Lerche, P. J. Lomas, M. Nocente, C. Reux, F. G. Rimini, A. C. C. Sips, D. Van Eester
Summary: The study shows that thermal fusion gain increases linearly with normalized plasma pressure and confinement, while predicting BT neutrons is more difficult and usually requires numerical treatment. Central fast ion densities decrease with increased density and density peaking, attributed to poorer beam penetration in high density conditions. The impact of NB/RF synergistic effects on total neutron rate is negligible due to reduced beam penetration in high-density conditions.
Article
Physics, Fluids & Plasmas
G. Pucella, P. Buratti, E. Giovannozzi, E. Alessi, F. Auriemma, D. Brunetti, D. R. Ferreira, M. Baruzzo, D. Frigione, L. Garzotti, E. Joffrin, E. Lerche, P. J. Lomas, S. Nowak, L. Piron, F. Rimini, C. Sozzi, D. Van Eester
Summary: The study investigates the onset of tearing modes in the termination phase of plasma pulses on JET. It shows that changes in the current density and electron temperature profiles can increase the probability of destabilizing tearing modes, even in the absence of an external trigger. By defining new parameters and introducing an empirical stability diagram, the analysis of a large data-set in high-current scenarios provides insights into the criteria for disruption alerts based on risk indicators for MHD instabilities.
Article
Physics, Fluids & Plasmas
A. Loarte, A. R. Polevoi, M. Schneider, S. D. Pinches, E. Fable, E. Militello Asp, Y. Baranov, F. Casson, G. Corrigan, L. Garzotti, D. Harting, P. Knight, F. Koechl, V. Parail, D. Farina, L. Figini, H. Nordman, P. Strand, R. Sartori
Summary: The study assessed the optimal conditions for access to and sustainment of H-mode plasmas in the PFPO-1 phase of the ITER research plan. It compared predictions with experiments carried out at JET and ASDEX Upgrade, finding reasonable agreement for global H-mode properties and scale lengths of density and temperature profiles. Specific integration issues of the PFPO-1 H-mode plasma scenarios were discussed, taking into account the impact of ITER tokamak design specifics.
Article
Physics, Fluids & Plasmas
A. R. Field, S. Aleiferis, E. Belonohy, P. Carvalho, I Coffey, D. Frigione, L. Garzotti, L. Horvath, Hyun-Tae Kim, M. Lennholm, E. Lerche, P. Lomas, C. G. Lowry, J. Mailloux, F. Rimini, C. M. Roach, M. Sertoli, Z. Stancar, G. Szepesi, D. van Eester
Summary: High-performance ITER-baseline scenario plasmas can sustain operation at high levels of input power, around 40MW.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Physics, Fluids & Plasmas
B. Lomanowski, M. Dunne, N. Vianello, S. Aleiferis, M. Brix, J. Canik, I. S. Carvalho, L. Frassinetti, D. Frigione, L. Garzotti, M. Groth, A. Meigs, S. Menmuir, M. Maslov, T. Pereira, C. Perez von Thun, M. Reinke, D. Refy, F. Rimini, G. Rubino, P. A. Schneider, G. Sergienko, A. Uccello, D. Van Eester
Summary: This study investigates the relationship between the electron temperature and plasma parameters. The decrease in electron temperature leads to degraded core plasma performance and changes in parameters related to the recycling and detachment of the plasma.
Article
Physics, Fluids & Plasmas
V. K. Zotta, L. Garzotti, F. J. Casson, D. Frigione, F. Kochl, E. Lerche, P. Lomas, F. Rimini, M. Sertoli, D. Van Eester, R. Gatto, C. Mazzotta, G. Pucella
Summary: The fusion performance of ELMy H-mode 50-50 DT plasmas was predicted using the JINTRAC suite of codes and the QuaLiKiZ transport model. The simulations analyzed the sensitivity of the predictions to plasma parameters and auxiliary heating power, showing that a fusion power of 10 MW should be achievable under a wide range of assumptions, while higher fusion power approaching 15 MW could be achieved with particularly pure plasmas and additional heating power of 40 MW.
Article
Physics, Fluids & Plasmas
J. Garcia, E. de la Luna, M. Sertoli, F. J. Casson, S. Mazzi, Z. Stancar, G. Szepesi, D. Frigione, L. Garzotti, F. Rimini, D. van Eester, P. Lomas, C. Sozzi, N. Aiba, M. Dicorato, A. Mariani, R. Coelho, L. Frasinetti, G. T. A. Huijsmans, F. Liu
Summary: New H-mode regimes with high confinement, low core impurity accumulation, and small edge-localized mode perturbations have been achieved in magnetically confined plasmas at the Joint European Torus tokamak. Optimized particle fueling conditions at high input power, current, and magnetic field lead to a self-organized state with increased rotation and ion temperature and decreased edge density. An interplay between core and edge plasma regions reduces turbulence levels and outward impurity convection. These results provide an attractive alternative to standard plasmas for fusion energy generation in a tokamak with a metallic wall environment, such as ITER.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
D. Van Eester, E. Lerche, P. Huynh, T. Johnson, D. Yadikin, Z. Stancar, S. Aleiferis, D. Frigione, L. Garzotti, P. Lomas, C. Lowry, M. Maslov
Summary: JET has neutral beam injection and a radio frequency system for plasma heating. When heating, using pure D beams is more efficient than combined D and T beams or pure T beams. RF heating allows efficient heating in the core region.
PLASMA PHYSICS AND CONTROLLED FUSION
(2022)
Article
Physics, Fluids & Plasmas
S. Mazzi, Y. Camenen, J. Garcia, D. Zarzoso, D. Frigione, L. Garzotti, F. Rimini, D. Van Eester
Summary: The impact of parallel flow shear on the stability and turbulent transport of tokamak plasma driven by ion temperature gradient modes has been analyzed using local gyrokinetic numerical simulations. It was found that parallel flow shear increases the growth rate of ion temperature gradient modes in the linear regime and causes broadening and shifting of the radial spectrum. Nonlinear effects of finite parallel shear on turbulent characteristics were also studied, showing that it reduces the thermal ion turbulent heat flux through the nonlinear generation of enhanced zonal flow activity.
Article
Physics, Fluids & Plasmas
E. Militello Asp, G. Corrigan, P. da Silva Aresta Belo, L. Garzotti, D. M. Harting, F. Kochl, V Parail, M. Cavinato, A. Loarte, M. Romanelli, R. Sartori
Summary: This paper presents integrated simulations of fueling ITER plasmas with gas and/or pellets using JINTRAC codes. The simulations show that operational limits can be respected, and various scenarios can be achieved for different plasma modes and transitions. The simulations provide valuable insights for the commissioning and operation of ITER and demonstrate the importance of accurate control over radiation.
Article
Physics, Fluids & Plasmas
D. Gallart, M. J. Mantsinen, J. Manyer, E. Planas, D. M. A. Taylor, J. Garcia, D. Frigione, L. Garzotti, Hyun-Tae Kim, M. Nocente, F. Rimini, D. Van Eester
Summary: This study investigates the impact of external heating on high fusion performance in the JET tokamak, with a focus on the H and He-3 minority schemes. The results suggest that both schemes can increase fusion yield within certain concentration ranges.
PLASMA PHYSICS AND CONTROLLED FUSION
(2022)
Article
Physics, Fluids & Plasmas
M. Marin, J. Citrin, C. Giroud, C. Bourdelle, Y. Camenen, L. Garzotti, A. Ho, M. Sertoli
Summary: Nuclear fusion reactor plasmas need to release a significant amount of energy through radiation for acceptable divertor loads. Impurities injected from the plasma edge can provide this through line radiation. However, there are limitations on the sustainable impurity content due to deleterious effects on electron heat sink and fuel availability. Recent experiments at JET show that neon-seeded discharges improve plasma confinement compared to purer plasmas, and this improvement is explained by higher pedestal temperature, increased rotation shear, and impurity-induced microturbulence stabilization.
Article
Physics, Fluids & Plasmas
S. Gabriellini, L. Garzotti, V. K. Zotta, C. Bourdelle, F. J. Casson, J. Citrin, D. Frigione, R. Gatto, C. Giroud, F. Koechl, P. Lomas, M. Marin, S. Menmuir, G. Pucella, F. Rimini, D. van Eester, JET Contributors
Summary: We present a fully predictive modelling of two JET-ILW high-performance baseline plasmas, comparing a Ne seeded shot and an equivalent unseeded one. The results suggest that the improved performance of the Ne seeded shot is due to a combination of turbulence stabilization and improved pedestal parameters.
Article
Physics, Fluids & Plasmas
J. Garcia, F. J. Casson, L. Frassinetti, D. Gallart, L. Garzotti, H. -t. Kim, M. Nocente, S. Saarelma, F. Auriemma, J. Ferreira, S. Gabriellini, A. Ho, P. Huynh, K. K. Kirov, E. Lerche, M. J. Mantsinen, V. K. Zotta, Z. Stancar, D. M. A. Taylor, D. Van Eester, C. D. Challis, JET Contributors
Summary: For more than a decade, an unprecedented predict-first activity has been carried out to predict fusion power and provide guidance to the DTE2 campaign. It is shown that detailed physics-based predictions are necessary and a combination of different modeling complexities and an extended interplay between modeling and experiment are essential for reliable predictions of D-T plasmas.
