Pub Date : 2026-01-15DOI: 10.1016/j.fpp.2026.100108
Ashok D. Mankani , Priyesh Chauhan , Suryakant Gupta , Saurabh Kumar , Amal S , Aritra Chakraborty , Aditya Naugraiya , Meddi Tharun , Abhishek Singh , Paul Christian , Ujjwal Kumar Baruah
Institute for Plasma Research (IPR), a premier national institute working in the field of plasma physics and nuclear fusion has designed a 500 kV/2 A DC High Voltage Power Supply (HVPS) System. This power supply is best suited for High Power (≥ 1 MW) and High Energy (≥100 keV) Neutral Beam Injector (NBI), an important Heating & Current Drive System used in magnetic confinement reactor TOKAMAK. The HVPS design emphasizes on its tight performance requirements viz. wider output voltage control range (20 % - 100 %), stability (≤ 1 %), ripple (≤ 5 %), fast turn ON & OFF time (few tens of µsec), repeated breakdown withstand capability together with lower input harmonics and near unity power factor. The design also takes into account the modularity, scalability, reliability, availability and maintainability aspects. The power supply comprises of a thyristor controlled rectifier forming common DC-Link powering the five stages of Inverter coupled High Voltage Transformer Rectifiers Units (HV-TRU). The output of each HV-TRUs are connected in series to produce 500 kV DC output. This paper elaborates the design of HVPS for NBI system including component sizing, selection, and topology of all the key elements of the power supply system supported by the simulation analysis carried out in ®MATLAB/Simulink/SimPowerSys validating the functional and performance requirements mentioned above.
{"title":"Design and analysis of high voltage DC power supply system for the nuclear fusion application","authors":"Ashok D. Mankani , Priyesh Chauhan , Suryakant Gupta , Saurabh Kumar , Amal S , Aritra Chakraborty , Aditya Naugraiya , Meddi Tharun , Abhishek Singh , Paul Christian , Ujjwal Kumar Baruah","doi":"10.1016/j.fpp.2026.100108","DOIUrl":"10.1016/j.fpp.2026.100108","url":null,"abstract":"<div><div>Institute for Plasma Research (IPR), a premier national institute working in the field of plasma physics and nuclear fusion has designed a 500 kV/2 A DC High Voltage Power Supply (HVPS) System. This power supply is best suited for High Power (≥ 1 MW) and High Energy (≥100 keV) Neutral Beam Injector (NBI), an important Heating & Current Drive System used in magnetic confinement reactor TOKAMAK. The HVPS design emphasizes on its tight performance requirements viz. wider output voltage control range (20 % - 100 %), stability (≤ 1 %), ripple (≤ 5 %), fast turn ON & OFF time (few tens of µsec), repeated breakdown withstand capability together with lower input harmonics and near unity power factor. The design also takes into account the modularity, scalability, reliability, availability and maintainability aspects. The power supply comprises of a thyristor controlled rectifier forming common DC-Link powering the five stages of Inverter coupled High Voltage Transformer Rectifiers Units (HV-TRU). The output of each HV-TRUs are connected in series to produce 500 kV DC output. This paper elaborates the design of HVPS for NBI system including component sizing, selection, and topology of all the key elements of the power supply system supported by the simulation analysis carried out in ®MATLAB/Simulink/SimPowerSys validating the functional and performance requirements mentioned above.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"17 ","pages":"Article 100108"},"PeriodicalIF":0.0,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996460","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}
Self-consistent, one-dimensional quasineutral screw-pinch equilibria are constructed within a hybrid model that couples fluid electrons with kinetic ions governed by the Vlasov equation. The equilibria depend on the radial coordinate perpendicular to the cylindrical axis and include an axial background magnetic field. Adopting a three-parameter ion distribution function depending on the energy and the canonical momenta conjugate to the two ignorable coordinates, the problem is reduced to a set of four quasilinear ODEs which are solved numerically. Both static equilibria and equilibria with macroscopic ion sheared velocities are obtained. The pressure of the electron fluid is isotropic and the electron contribution to the current density is parallel to the magnetic field, while the kinetic ions are associated with a non-gyrotropic pressure tensor. By means of the solutions the various equilibrium quantities are calculated and the impact of the free parameters on the equilibrium characteristics is examined.
{"title":"Hybrid fluid-kinetic cylindrical equilibria with axial background magnetic field","authors":"D.A. Kaltsas , A.I. Kuiroukidis , G.N. Throumoulopoulos","doi":"10.1016/j.fpp.2025.100105","DOIUrl":"10.1016/j.fpp.2025.100105","url":null,"abstract":"<div><div>Self-consistent, one-dimensional quasineutral screw-pinch equilibria are constructed within a hybrid model that couples fluid electrons with kinetic ions governed by the Vlasov equation. The equilibria depend on the radial coordinate perpendicular to the cylindrical axis and include an axial background magnetic field. Adopting a three-parameter ion distribution function depending on the energy and the canonical momenta conjugate to the two ignorable coordinates, the problem is reduced to a set of four quasilinear ODEs which are solved numerically. Both static equilibria and equilibria with macroscopic ion sheared velocities are obtained. The pressure of the electron fluid is isotropic and the electron contribution to the current density is parallel to the magnetic field, while the kinetic ions are associated with a non-gyrotropic pressure tensor. By means of the solutions the various equilibrium quantities are calculated and the impact of the free parameters on the equilibrium characteristics is examined.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"16 ","pages":"Article 100105"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623769","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}
In magnetically confined plasmas, gradients in density, temperature, and magnetic field generate low-frequency drift waves, which resonantly interact with plasma particles. In this investigation, we consider a nonlinear process due to which the energy of an accelerated particle may transfer to the O-mode present in the confined plasma system through a modulated field. This nonlinear process is based on a kinetic approach, analyzed using the Vlasov-Maxwell model system of equations. In this study, we derive the nonlinear dispersion relation for the O-mode incorporating gradient parameters and estimate its growth rate. Observational data from the Earth’s magnetosphere are used to analyze the influence of these gradient parameters and other plasma conditions. The results are relevant in predicting O-mode instabilities in inhomogeneous confined plasma systems, like Tokamaks, magnetospheric plasmas, etc.
{"title":"Unstable O-mode generation in confined plasmas with multi-parametric gradient effects","authors":"Banashree Saikia , Paramananda Deka , Pralay Kumar Karmakar","doi":"10.1016/j.fpp.2025.100104","DOIUrl":"10.1016/j.fpp.2025.100104","url":null,"abstract":"<div><div>In magnetically confined plasmas, gradients in density, temperature, and magnetic field generate low-frequency drift waves, which resonantly interact with plasma particles. In this investigation, we consider a nonlinear process due to which the energy of an accelerated particle may transfer to the O-mode present in the confined plasma system through a modulated field. This nonlinear process is based on a kinetic approach, analyzed using the Vlasov-Maxwell model system of equations. In this study, we derive the nonlinear dispersion relation for the O-mode incorporating gradient parameters and estimate its growth rate. Observational data from the Earth’s magnetosphere are used to analyze the influence of these gradient parameters and other plasma conditions. The results are relevant in predicting O-mode instabilities in inhomogeneous confined plasma systems, like Tokamaks, magnetospheric plasmas, etc.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"16 ","pages":"Article 100104"},"PeriodicalIF":0.0,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529019","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}
The light emitted spectra of air and air/argon plasmas at ambient pressure in a dielectric barrier discharge (DBD) operating at power supply frequency, 50 Hz, were recorded using an optical emission spectrometer (OES). The spectra cover the full wavelength range from 2000 A0 to 11,000 A0. It was found that air/argon plasma displays the radical composed of OH (A²Σ⁺(v′=0) → X²Π(v″=0)) at 3090 A0, a feature not observed in air plasma. The LIFBASE software suite was utilized to obtain the best fit between simulated and experimental spectra. At a voltage amplitude of 11.6 kV and a discharge gap of 0.3 cm, the plasma gas temperature, determined from the OH (3090 A0) line, was found to be 420 ± 10 K. Additionally, the intensity of the OH radical (3090A0) in air/argon plasma was studied in relation to the argon gas flow rate, applied voltage, and discharge gap. The results showed that, at a constant discharge gap, the OH intensity increases with higher argon flow and applied voltage. However, as the discharge gap increases, the OH intensity first rises and then decreases. The maximum OH intensity for a given applied voltage occurs at a discharge gap of 0.3 cm. Furthermore, the electrical diagnostics of air/argon plasma were done. Using the current density method, the electron concentration was found to be around 1017 m-3. Analysis of the current and voltage waveforms, along with the Lissajous figure approach, indicated that the reactor's power consumption was 6.2 watts. These findings contribute to a better understanding of DBD plasma's physical and chemical properties, and its potential applications in fields such as plasma agriculture, plasma chemistry and plasma medicine.
{"title":"Study of hydroxyl radical (A,0) generated in DBD at ambient pressure with power supply frequency 50 Hz","authors":"Akhilesh Kumar Singh , Rajesh Prakash Guragain , Keshav Raj Sigdel , Ganesh Kuwar Chhetri , Hom Bahadur Baniya , Deepak Prasad Subedi , Ujjwal Man Joshi","doi":"10.1016/j.fpp.2025.100100","DOIUrl":"10.1016/j.fpp.2025.100100","url":null,"abstract":"<div><div>The light emitted spectra of air and air/argon plasmas at ambient pressure in a dielectric barrier discharge (DBD) operating at power supply frequency, 50 Hz, were recorded using an optical emission spectrometer (OES). The spectra cover the full wavelength range from 2000 A<sup>0</sup> to 11,000 A<sup>0</sup>. It was found that air/argon plasma displays the radical composed of OH (A²Σ⁺(v′=0) → X²Π(v″=0)) at 3090 A<sup>0</sup>, a feature not observed in air plasma. The LIFBASE software suite was utilized to obtain the best fit between simulated and experimental spectra. At a voltage amplitude of 11.6 kV and a discharge gap of 0.3 cm, the plasma gas temperature, determined from the OH (3090 A<sup>0</sup>) line, was found to be 420 ± 10 K. Additionally, the intensity of the OH radical (3090A<sup>0</sup>) in air/argon plasma was studied in relation to the argon gas flow rate, applied voltage, and discharge gap. The results showed that, at a constant discharge gap, the OH intensity increases with higher argon flow and applied voltage. However, as the discharge gap increases, the OH intensity first rises and then decreases. The maximum OH intensity for a given applied voltage occurs at a discharge gap of 0.3 cm. Furthermore, the electrical diagnostics of air/argon plasma were done. Using the current density method, the electron concentration was found to be around 10<sup>17</sup> m<sup>-3</sup>. Analysis of the current and voltage waveforms, along with the Lissajous figure approach, indicated that the reactor's power consumption was 6.2 watts. These findings contribute to a better understanding of DBD plasma's physical and chemical properties, and its potential applications in fields such as plasma agriculture, plasma chemistry and plasma medicine.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"16 ","pages":"Article 100100"},"PeriodicalIF":0.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145365824","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}
Pub Date : 2025-09-01DOI: 10.1016/j.fpp.2025.100099
Giovanni Lapenta , Jean Berchem , Mostafa El-Alaoui , Raymond Walker , Harikrishnan Aravindakshan , Nadja Reisinger , Francesco Pucci , Giuseppe Arrò , Fabio Bacchini
We present a method to visualize and analyze turbulence within macroscopic flows that feature complex structures not determined by the turbulence itself. We introduce a technique to shift to a Lagrangian frame that captures the macroscopic scales not part of the turbulent cascade. We then study turbulence within this frame that is comoving with the large-scale nonturbulent flow. The method is applied to Particle-in-Cell simulations of astrophysical plasma. Specifically, we use two cases to illustrate the new method. First, we consider a magnetic perturbation in the solar wind interacting with the bow shock, magnetosheath, and magnetopause in the dayside of the Earth. Second, we consider an Earthward flow generated by magnetic reconnection in the magnetotail. In these cases we show how the Lagrangian frame can be used to distinguish turbulent fluctuations from the macroscopic flow structures due to the evolution of the system caused by macroscopic forcing.
{"title":"A Lagrangian-frame technique for investigating plasma turbulence in complex underlying system-scale structures","authors":"Giovanni Lapenta , Jean Berchem , Mostafa El-Alaoui , Raymond Walker , Harikrishnan Aravindakshan , Nadja Reisinger , Francesco Pucci , Giuseppe Arrò , Fabio Bacchini","doi":"10.1016/j.fpp.2025.100099","DOIUrl":"10.1016/j.fpp.2025.100099","url":null,"abstract":"<div><div>We present a method to visualize and analyze turbulence within macroscopic flows that feature complex structures not determined by the turbulence itself. We introduce a technique to shift to a Lagrangian frame that captures the macroscopic scales not part of the turbulent cascade. We then study turbulence within this frame that is comoving with the large-scale nonturbulent flow. The method is applied to Particle-in-Cell simulations of astrophysical plasma. Specifically, we use two cases to illustrate the new method. First, we consider a magnetic perturbation in the solar wind interacting with the bow shock, magnetosheath, and magnetopause in the dayside of the Earth. Second, we consider an Earthward flow generated by magnetic reconnection in the magnetotail. In these cases we show how the Lagrangian frame can be used to distinguish turbulent fluctuations from the macroscopic flow structures due to the evolution of the system caused by macroscopic forcing.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"15 ","pages":"Article 100099"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321236","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}
Pub Date : 2025-09-01DOI: 10.1016/j.fpp.2025.100097
Matteo Lo Verso , Carolina Introini , Eric Cervi , Matteo Di Prinzio , Marco Caramello , Francesca Giacobbo , Francois Foulon , Xiang Wang , Laura Savoldi , Antonio Cammi
The research and experimentation in the field of magnetic confinement fusion is constantly advancing. For precise control of the thermonuclear plasma and the operating fluids in fusion reactors, it is essential to reach a comprehensive understanding of the behavior of conducting fluids interacting with magnetic fields. This study focuses on one of the options envisaged for the breeding blanket of the future tokamaks and explores the impact of different magnetic profiles on the flow regime of lead-lithium. The stability of magnetohydrodynamic (MHD) flow in an infinite pipe is investigated, with a focus on the influence of the applied magnetic field on fluid dynamics. This study specifically compares the effects of magnetic fields with different intensity on the general stability. Both the classical modal stability analysis and the more recent non-modal approach have been adopted to study, respectively, the asymptotic and the short-term evolution of the magnetohydrodyamic system after perturbations in the applied magnetic field or in the thermofluid regime. The results highlight the importance of using the non-modal stability, which allows to investigate the transient growths experienced by the perturbed system, a phenomenon not observable by modal stability analysis alone. Additionally, a zero-dimensional lumped model of the lead-lithium pipe flow is examined to study the impact of thermal effects on system stability and wall deformations of the pipe. The results suggest that the deformation effects experienced by the walls due to temperature oscillations in the perturbed system are negligible.
{"title":"Non-modal stability analysis of magnetohydrodynamic flows for liquid metal blankets of fusion reactors","authors":"Matteo Lo Verso , Carolina Introini , Eric Cervi , Matteo Di Prinzio , Marco Caramello , Francesca Giacobbo , Francois Foulon , Xiang Wang , Laura Savoldi , Antonio Cammi","doi":"10.1016/j.fpp.2025.100097","DOIUrl":"10.1016/j.fpp.2025.100097","url":null,"abstract":"<div><div>The research and experimentation in the field of magnetic confinement fusion is constantly advancing. For precise control of the thermonuclear plasma and the operating fluids in fusion reactors, it is essential to reach a comprehensive understanding of the behavior of conducting fluids interacting with magnetic fields. This study focuses on one of the options envisaged for the breeding blanket of the future tokamaks and explores the impact of different magnetic profiles on the flow regime of lead-lithium. The stability of magnetohydrodynamic (MHD) flow in an infinite pipe is investigated, with a focus on the influence of the applied magnetic field on fluid dynamics. This study specifically compares the effects of magnetic fields with different intensity on the general stability. Both the classical modal stability analysis and the more recent non-modal approach have been adopted to study, respectively, the asymptotic and the short-term evolution of the magnetohydrodyamic system after perturbations in the applied magnetic field or in the thermofluid regime. The results highlight the importance of using the non-modal stability, which allows to investigate the transient growths experienced by the perturbed system, a phenomenon not observable by modal stability analysis alone. Additionally, a zero-dimensional lumped model of the lead-lithium pipe flow is examined to study the impact of thermal effects on system stability and wall deformations of the pipe. The results suggest that the deformation effects experienced by the walls due to temperature oscillations in the perturbed system are negligible.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"15 ","pages":"Article 100097"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020672","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}
Pub Date : 2025-09-01DOI: 10.1016/j.fpp.2025.100098
J. Biu , R. Jorge
Stellarators are fusion energy devices that confine a plasma using non-axisymmetric magnetic fields. Complex coils with tight construction tolerances are needed to create such fields. To simplify such coils, we use a method here to create filamentary curves bounded to a coil winding surface. This approach bypasses the need to find contours of the current potential in that surface while allowing gradients to be obtained for both the winding surface and the coil shapes. The parameterization of the coil curves allows the modeling of both modular and helical coils. As an application, we optimize a set of coils to reproduce a quasisymmetric stellarator equilibrium. A comparison is performed between coils parameterized in two different winding surfaces, namely an axisymmetric circular toroidal surface and a surface rescaled from the plasma boundary. Finally, an analysis is performed on the optimal distance between the plasma and the coil winding surface.
{"title":"Axisymmetric coil winding surfaces for non-axisymmetric fusion devices","authors":"J. Biu , R. Jorge","doi":"10.1016/j.fpp.2025.100098","DOIUrl":"10.1016/j.fpp.2025.100098","url":null,"abstract":"<div><div>Stellarators are fusion energy devices that confine a plasma using non-axisymmetric magnetic fields. Complex coils with tight construction tolerances are needed to create such fields. To simplify such coils, we use a method here to create filamentary curves bounded to a coil winding surface. This approach bypasses the need to find contours of the current potential in that surface while allowing gradients to be obtained for both the winding surface and the coil shapes. The parameterization of the coil curves allows the modeling of both modular and helical coils. As an application, we optimize a set of coils to reproduce a quasisymmetric stellarator equilibrium. A comparison is performed between coils parameterized in two different winding surfaces, namely an axisymmetric circular toroidal surface and a surface rescaled from the plasma boundary. Finally, an analysis is performed on the optimal distance between the plasma and the coil winding surface.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"15 ","pages":"Article 100098"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107691","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}
Pub Date : 2025-09-01DOI: 10.1016/j.fpp.2025.100096
Emilia R. Solano
The recent ITER re-baselining calls for new fusion-relevant research best carried out in a DT-capable tokamak device with similar technical choices. The present paper describes key issues that could be addressed in a Suitably Enhanced DT-capable Tokamak (SET), with tungsten plasma facing components, boronization systems, and 10 MW of ECRH, based on JET’s characteristics and knowledgebase. We discuss hardware options, and show that fusion-relevant operational scenarios could be achieved. Notably, development, validation and testing of fusion and nuclear diagnostics, to be used in next generation devices, would require a DT-capable tokamak as described.
{"title":"Fusion research in a Deuterium-Tritium tokamak","authors":"Emilia R. Solano","doi":"10.1016/j.fpp.2025.100096","DOIUrl":"10.1016/j.fpp.2025.100096","url":null,"abstract":"<div><div>The recent ITER re-baselining calls for new fusion-relevant research best carried out in a DT-capable tokamak device with similar technical choices. The present paper describes key issues that could be addressed in a Suitably Enhanced DT-capable Tokamak (SET), with tungsten plasma facing components, boronization systems, and 10 MW of ECRH, based on JET’s characteristics and knowledgebase. We discuss hardware options, and show that fusion-relevant operational scenarios could be achieved. Notably, development, validation and testing of fusion and nuclear diagnostics, to be used in next generation devices, would require a DT-capable tokamak as described.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"15 ","pages":"Article 100096"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107732","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}
Pub Date : 2025-04-29DOI: 10.1016/j.fpp.2025.100092
Keiichiro Takeda , Naoki Sato
We present the noncanonical Hamiltonian structure of the relativistic Euler equations for a perfect fluid in Minkowski spacetime. By identifying the system’s noncanonical Poisson bracket and Hamiltonian, we show that relativistic fluid flows preserve helicity and enstrophy as conserved quantities in three-dimensional and two-dimensional cases, respectively. This holds when the fluid follows a relativistic -barotropic equation of state, which generalizes the classical barotropic condition. Furthermore, we demonstrate that these conserved quantities are Casimir invariants associated with the noncanonical Poisson structure. These findings open new avenues for applying Hamiltonian theory to the study of astrophysical fluids and relativistic plasmas.
{"title":"Revealing noncanonical Hamiltonian structures in relativistic fluid dynamics","authors":"Keiichiro Takeda , Naoki Sato","doi":"10.1016/j.fpp.2025.100092","DOIUrl":"10.1016/j.fpp.2025.100092","url":null,"abstract":"<div><div>We present the noncanonical Hamiltonian structure of the relativistic Euler equations for a perfect fluid in Minkowski spacetime. By identifying the system’s noncanonical Poisson bracket and Hamiltonian, we show that relativistic fluid flows preserve helicity and enstrophy as conserved quantities in three-dimensional and two-dimensional cases, respectively. This holds when the fluid follows a relativistic <span><math><mi>γ</mi></math></span>-barotropic equation of state, which generalizes the classical barotropic condition. Furthermore, we demonstrate that these conserved quantities are Casimir invariants associated with the noncanonical Poisson structure. These findings open new avenues for applying Hamiltonian theory to the study of astrophysical fluids and relativistic plasmas.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"14 ","pages":"Article 100092"},"PeriodicalIF":0.0,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912896","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}
Pub Date : 2025-03-13DOI: 10.1016/j.fpp.2025.100088
Anandam Choudhary , Laxman Prasad Goswami , C. Aparajit , Amit D. Lad , Ameya Parab , Yash M. Ved , Trishul Dhalia , Amita Das , G. Ravindra Kumar
The interaction of intense linearly polarized (LP) femtosecond laser pulses with solids is known to generate azimuthal magnetic fields, while circularly polarized (CP) light has been shown to create axial fields. We demonstrate through experiments and particle-in-cell simulations that circularly polarized light can generate both axial and azimuthal fields of comparable magnitude in a plasma created in a solid. Angular distributions of the generated fast electrons at the target front and rear show significant differences between the results for the two polarization states, with circular polarization enforcing more axial confinement. The measurement of the spatial distribution of both types of magnetic fields captures their turbulent evolution.
{"title":"Generation of mega-gauss axial and azimuthal magnetic fields in a solid plasma by ultrahigh intensity, circularly polarized femtosecond laser pulses","authors":"Anandam Choudhary , Laxman Prasad Goswami , C. Aparajit , Amit D. Lad , Ameya Parab , Yash M. Ved , Trishul Dhalia , Amita Das , G. Ravindra Kumar","doi":"10.1016/j.fpp.2025.100088","DOIUrl":"10.1016/j.fpp.2025.100088","url":null,"abstract":"<div><div>The interaction of intense linearly polarized (LP) femtosecond laser pulses with solids is known to generate azimuthal magnetic fields, while circularly polarized (CP) light has been shown to create axial fields. We demonstrate through experiments and particle-in-cell simulations that circularly polarized light can generate both axial and azimuthal fields of comparable magnitude in a plasma created in a solid. Angular distributions of the generated fast electrons at the target front and rear show significant differences between the results for the two polarization states, with circular polarization enforcing more axial confinement. The measurement of the spatial distribution of both types of magnetic fields captures their turbulent evolution.</div></div>","PeriodicalId":100558,"journal":{"name":"Fundamental Plasma Physics","volume":"14 ","pages":"Article 100088"},"PeriodicalIF":0.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852144","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}