Multi-Scale Numerical Modelling of Magnetised Plasma Turbulence

Lead Research Organisation: University of Strathclyde
Department Name: Physics

Abstract

The majority of the visible matter in our universe is plasma. Since plasma contains free electric charges (ions and electrons), it is sensitive to electromagnetic fields and waves, and electric currents can flow in the plasma. Laboratory plasmas are being increasingly exploited in contemporary high-value, high-technology industries. Plasma in the sun, magnetosphere and ionosphere have impacts on many human activities, from space weather to GPS satellite and landbased communications. For the longer term future the harnessing of fusion energy to provide the world's energy needs in an environmentally safe, carbon-free way may be based on magnetically or inertially confined plasmas. Electromagnetic waves are used to heat plasma in fusion reactors, but they are also used for basic plasma experiments in the laboratory and in the Earth's ionosphere, and for satellite communication and GPS.

This project aims to build a comprehensive multi-dimensional, full-scale numerical model to study the propagation and the complicated interactions between high-frequency electromagnetic waves and magnetised plasmas on different length- and timescales. The results of the project will develop our understanding of the complex interactions between electromagnetic waves, such as microwaves, and plasmas, and how electromagnetic waves can be used to inject energy into the plasma. The project is timely in view of the ongoing construction of the fusion test reactor ITER in Southern France, and the results will also provide a pre-study for planned laboratory plasma experiments at the University of Strathclyde. The project also has relevance to active experiments using the Earth's ionosphere as a natural plasma laboratory, and to satellite communication where the effects of the ionospheric plasma layer need to be compensated for.

Planned Impact

The impact of plasma physics is large and growing. The majority of the visible matter in our universe is plasma. Laboratory plasmas are being increasingly exploited in contemporary high-value, high-technology industries. Plasma in the sun, magnetosphere and ionosphere have impacts on many human activities, from space weather to GPS satellite and land-based communications. The development of fusion energy is based on two plasma approaches, (1) magnetically confined plasmas and (2) inertially confined plasmas. In 1997 the JET plasma facility successfully produced fusion power using method (1) at 16MW for about one second and now the much larger ITER (10 billion Euro) facility is being built in southern France. ITER is designed to produce fusion power by magnetic plasma confinement at up to 0.5GW power levels for periods of 10 minutes. Demonstrating a practical GW level fusion power station will be the aim of the follow-on DEMO facility. Such demonstrations of energy production by fusion would have enormous impact on energy policy.

Our objectives will complement the UK's world leading activity in fusion and industrial processing plasmas, through the numerical investigation of the interactions between large amplitude electromagnetic waves and magnetised plasmas. Electromagnetic waves will be one of the main sources of heating the plasma in ITER and will be investigated for current drive in stage 2 of the MAST-Upgrade. The understanding of the propagation of EM waves in magnetised plasmas is also needed for satellite communication, where interference from the sometimes turbulent ionospheric plasma needs to be compensated for. To achieve this we anticipate maintaining close contact with colleagues working in different areas of plasma physics, ensuring that the work we undertake is as relevant as possible to the problems they face.

This project has the potential to impact on principal approaches to magnetic confinement fusion science, on academic basic research of turbulence in magnetised plasmas, on EM wave propagation with relevance to remote sensing and satellite communication, and industrial applications to materials processing. The project will develop key skills in theoretical and numerical modelling of electromagnetic waves interacting with magnetised plasmas. The applicants have strong collaborative links to key labs and industrial partners (e.g. e2v and TMD technologies) providing the route to realise the impact to the benefit of society and the economy.

Publications

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Description Through the project, multiscale simulations have been developed to study the coupling between large and small scales in plasma. Such processes are important in fusion science, laboratory plasmas, and ionospheric experiments using the natural plasma as a laboratory. Small-scale behaviour in plasma have often been neglected in present-day simulations, leading to poor agreement between the simulations and experiment. Through this project, multiscale processes are inocorporated into the simulation model so that quantitative agreement can be obtained between simulation and observations.
Exploitation Route The simulation techniques are of general interest in the wider plasma physics community such as magnetic confinement fusion, laboratory plasmas, and active ionospheric physics experiments. The respective community can adapt the multiscale modelling techniques to fit their specific needs.
Sectors Energy,Environment,Other

 
Title Data for "Controlled beat-wave Brillouin scattering in the ionosphere" 
Description The dataset contains experimental data as well as simulation data used to analyse an ionospheric beat wave Brillouin scattering experiment experiment carried out at the EISCAT facility in Tromso, Northern Norway, 29 November 2014. More details on the data are given in the README file as well as in separate README files contained in each data file. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://pureportal.strath.ac.uk/en/datasets/d4ca75d2-a462-4940-9614-b1b3fe5a8e2e
 
Title Data for Large-scale Numerical Simulation of Ionospheric Langmuir Turbulence Excited by a Radio Frequency Electromagnetic Wave 
Description "This dataset contains simulation data generated by the simulation of an ionospheric heating experiment described in the article ""Data for Large-scale Numerical Simulation of Ionospheric Langmuir Turbulence Excited by a Radio Frequency Electromagnetic Wave"" published in the journal ""Plasma Physics and Controlled Fusion"". The data consists of periodic snapshots in time of the simulation variables stored in hdf5 format. MATLAB scripts to read and analyze the data are also included. See the README file for a detailed description. " 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact
 
Title Data for: "Observation of electron cyclotron harmonic emissions due to electrostatic instabilities in mirror-confined plasma" 
Description The dataset contains data and some Matlab scripts to analyze the data for wave electric fields from Vlasov simulations and dispersion diagrams and growth rates obtained by solving dispersion relations for electrostatic electron cyclotron instabilities in magnetized plasma. More details are given in the README file. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://pureportal.strath.ac.uk/en/datasets/45a4eb8b-4812-49ee-bf5e-1ba22b603690
 
Title Data for: "Simulations of the generation of energetic electrons and the formation of descending artificial plasma layers during HF-heating at Arecibo" 
Description HF-induced Descending Artificial Plasma Layers (DAPLs) are artificially ionized plasma layers with plasma density in excess of that of the F2-peak. They were discovered during HF heating experiments at HAARP where they descended up to 70 km from the initial O mode wave reflection height. The DAPLs were attributed to the ionization of the neutral gas by high-energy electrons accelerated by the artificial ionospheric turbulence. Recently, DAPL formation was reported during the HF-heating experiment at Arecibo by Bernhardt et al. [2017]. A model of artificial plasma layers created by the Arecibo HF facility is presented. It shows that Langmuir turbulence due to the HF heating can accelerate part of the ambient photoelectrons to energies above the ionization threshold of the neutral gas, leading to the formation of DAPLs. The dataset contains data (Excel format) supporting the figures in the published article "Simulations of the generation of energetic electrons and the formation of descending artificial plasma layers during HF-heating at Arecibo" by Eliasson, B., et al., Journal of Geophysical Research (2018). 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
 
Title Data for: "Time-dependent variational approach for Bose-Einstein condensates with nonlocal interaction" 
Description The dataset contains simulation data and Matlab scripts to analyse the dynamics of self-bound Bose-Einstein condensates with local and non-local interaction potentials. Three-dimensional simulations of the Gross-Pitaevskii equation (GPE) are compared with a simplified variational model resulting in ordinary differential equations (ODEs). Both Gaussian and more realistic Van der Waals-like potentials are analysed. The Matlab scripts simulate the governing equations and produce the phasemap plots comparing the 3D GPE and variational/ODE solutions. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact
 
Title Data for: "Two-dimensional Vlasov simulations of fast stochastic electron heating in ionospheric modification experiments" 
Description The dataset contains data from Vlasov simulations of the mode conversion and trapping of upper hybrid waves in a two-dimensional density depletion/striation. Nonlinear wave-couplings leading to upper hybrid and lower hybrid turbulence, and the excitation of electron Bernstein waves are studied, as well as stochastic heating of electrons by the large amplitude electrostatic waves. File details available in the README file. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact Unknown 
 
Title Data for: "Vlasov simulations of electron acceleration by radio frequency heating near the upper hybrid layer" 
Description It is shown by using a combination of Vlasov and test particles simulations that the electron distribution function resulting from energization due to Upper Hybrid (UH) plasma turbulence depends critically on the closeness of the pump wave to the double resonance, defined as ? ˜ ?UH ˜ n?ce, where n is an integer. For pump frequencies, away from the double resonance, the electron distribution function is very close to Maxwellian, while as the pump frequency approaches the double resonance, it develops a high energy tail. The simulations show turbulence involving coupling between Lower Hybrid (LH) and UH waves, followed by excitation of Electron Bernstein (EB) modes. For the particular case of a pump with frequency between n = 3 and n = 4, the EB modes cover the range from the first to the 5th mode. The simulations show that when the injected wave frequency is between the 3rd and 4th harmonics of the electron cyclotron frequency, bulk electron heating occurs due to the interaction between the electrons and large amplitude EB waves, primarily on the first EB branch leading to an essentially thermal distribution. On the other hand, when the frequency is slightly above the 4th electron cyclotron harmonic, the resonant interaction is predominantly due to the UH branch and leads to a further acceleration of high-velocity electrons and a distribution function with a suprathermal tail of energetic electrons. The results are consistent with ionospheric experiments and relevant to the production of Artificial Ionospheric Plasma Layers. Data originally held at the University of Maryland, see added link. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://pureportal.strath.ac.uk/en/datasets/aea67e00-0ca0-4dce-b46e-c2b475b527a5
 
Title Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions 
Description The dataset contains electric field and electron distribution function data as well as Python and Matlab scripts that were used to construct spectra and time-series of the electric field as well as plots of the distribution function for the electrostatic electron cyclotron instability involving combinations of ring distributions and cold Maxwellian distributions of electrons. More information about data formats and how to read the data are given in the associated README file. 
Type Of Material Database/Collection of data 
Year Produced 2015 
Provided To Others? Yes  
Impact n/a 
 
Title HF wave propagation and induced ionospheric turbulence in the magnetic equatorial region 
Description The dataset contains data from a simulation of turbulence induced by large amplitude electromagnetic waves injected into the Earth's ionosphere in the Earth's magnetic equatorial region. The data include the waveform of the electromagnetic field obtained in full-scale simulations, and data from local two-dimensional simulations of Langmuir turbulence resulting in large amplitude electrostatic fields. Finally the dataset also contains results of Fokker-Planck simulations of electrons accelerated by the turbulence forming high-energy tails in the distribution function. For more information on the data and file formats included in this dataset please see the associated README file. 
Type Of Material Database/Collection of data 
Year Produced 2016 
Provided To Others? Yes  
Impact n/a 
 
Title Nonlinear evolution of the electromagnetic electron-cyclotron instability in bi-Kappa distributed plasma 
Description Smulation data from Vlasov simulations of the electromagnetic electron cyclotron instability in a plasma with Kappa distributed electrons with temperature anisotropy. Each zip'ed folder contains data files and Matlab scripts that can be used to open the data. A README file is provided in each data set with further information on physical parameters used, and a brief description of the Matlab scripts used to read and analyse the data. 
Type Of Material Database/Collection of data 
Provided To Others? No  
Impact Not recorded 
 
Title Nonlinear plasmonics in a two-dimensional plasma layer 
Description The dataset contains data from a simulation of a modulational instability in a two-dimensional plasma layer with relevance to large amplitude plasmons in graphene and other two-dimensional plasmas. The data contains snapshots in time of the areal electron density and Matlab scripts to analyse the data and make the plots in the published article. For more information on the data and file formats included in this dataset please see the associated README file. 
Type Of Material Database/Collection of data 
Year Produced 2016 
Provided To Others? Yes  
Impact n/a 
 
Title Numerical study of upper hybrid to Z mode leakage during electromagnetic pumping of groups of striations in the ionosphere 
Description Smulation data from simulations of upper hybrid waves trapped in density depletions in a magnetised plasma, and the leaking of wave energy to electromagnetic waves in the Z mode branch. Each zip'ed folder contains data files and Matlab scripts that can be used to open the data. A README file is provided in each data set with further information on physical parameters used, and a brief description of the Matlab scripts used to read and analyse the data. 
Type Of Material Database/Collection of data 
Provided To Others? No  
Impact Not recorded 
 
Title Pitch angle scattering of relativistic electrons near EMIC resonances in diverging magnetic fields 
Description The dataset contains simulation data of the propagation of electromagnetic ion cyclotron (EMIC) waves in a plasma with diverging magnetic field. The data is part of a theoretical and numerical investigation of the pitch angle scattering of relativistic electrons on EMIC waves with relevance to the Earth's radiation belts in the ionosphere where trapped energetic particles constitute a hazard for satellites, and to laboratory experiments at the UCLA LAPD plasma chamber where EMIC wave propagation and pitch angle scattering can be studied experimentally. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact Unknown