Thermonuclear land of plenty

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Computational modeling of wave propagation in plasma physics over the Gilson–Pickering equation

Study of the dynamical nonlinear modified Korteweg–de Vries equation arising in plasma physics and its analytical wave solutions

This paper is a tutorial paper on the recent developments of plasma physics. Plasma physics has been systematized through intensive research efforts in various application fields. Recent developments are quite significant and this paper summarizes the important achievements in this field.

X‐ray Spectrometry Best Referee awards 2021

A plasma consists of charged particles moving relatively freely, but interacting through the electric and magnetic fields produced by each particle. It is well known that all except a very small (but nevertheless important) fraction of the detectable universe is a plasma. Most plasma physics can be expressed in terms of five fairly straightforward equations, the four Maxwell equations for electromagnetism and the equation of motion for charged particles in electromagnetic fields. Why then is plasma physics such a mathematically difficult subject and why is numerical simulation so important? The most basic reason is that any experimental plasma contains a very large number of particles, 1018–1020 in a typical fusion experiment. Moreover, particles in plasmas have a tendancy to act independently of each other. In conventional hydrodynamics, large numbers of particles can be described by a few simple numbers such as their temperature, density and mean velocity. Sometimes we can do this with a plasma but even then we have a few more numbers to include such as current and charge density, along with the electromagnetic fields. More usually, plasmas are not so simply described. Plasmas are not usually Maxwellian and we have to think in terms of distribution functions in phase space. Whenever we can, we model the non—Maxwellian nature of the plasma by transport models, e.g. for heat flow, but this is a specialised skill in itself. When one considers that conventional hydrodynamics is very complex and involves advanced numerical simulation, it is hardly surprising that simulation plays such an important role in plasma physics.

An overview is given of recent advances toward the realization of high density, high confinement plasmas with radiating mantles in limiter and divertor tokamaks worldwide. Radiatively improved mode discharges on the Torus Experiment for Technology Oriented Research 94 (TEXTOR-94) [Proceedings of the 16th IEEE Symposium on Fusion Engineering, 1995 (Institute for Electrical and Electronics Engineers, Piscataway, NJ, 1995), p. 470] have recently been obtained at trans-Greenwald densities (up to n̄/nGW=1.4) with high confinement mode free of edge localized modes (ELM-free H-mode) confinement quality. Experiments in DIII-D [J. Luxon et al., Proceedings of the 11th IAEA Conference on Plasma Physics and Controlled Nuclear Fusion Research (International Atomic Energy Association, Vienna, 1987), Vol. 1, p. 159] divertor plasmas with a low confinement mode edge have confirmed the dramatic changes in confinement observed with impurity seeding on TEXTOR-94. Recent experiment with impurity seeding on the Joint European Torus [Rebut et al., Fusion Eng. Des. 22, 7 (1993)], and the Japanese Atomic Energy Research Institute Tokamak 60 Upgrade [Horiike et al., Fusion Eng. Des. 16, 285 (1991); Hosogane et al., Proceedings of the 16th IAEA Conference on Plasma Physics and Controlled Nuclear Fusion Research Montreal, 1987 (International Atomic Energy Association, Vienna, 1987), Vol. 3, p. 555] have extended high confinement in ELMy H-mode plasmas to higher densities. Finally, recent progress in the physical understanding of radiating mantle plasmas is summarized.

Nuclear fusion research is entering a new phase, in which power exhaust will play a vital role. This book presents a complete and up-to-date summary of this emerging field of research in fusion plasmas, focusing on the leading tokamak concept. Emphasis is placed on rigorous theoretical development, supplemented by numerical simulations, which are used to explain and quantify a range of experimental observations. The text offers a self-contained introduction to power exhaust, and deals in detail with both edge plasma turbulence and edge localized modes, providing the necessary background to understand these important, yet complicated phenomena. Combining an in-depth overview with an instructive development of concepts, this is an invaluable resource for academic researchers and graduate students in plasma physics.

The contribution gives an overview over Research activities in the area of Plasma Physics within Philips Research.Besides the classical applications of Plasma Physics in Astrophysics and Nuclear Fusion Research, Plasma Physics has also opened the way to numerous technical applications today. Among those are plasma based surface treatments, deposition technologies, plasma induced catalysis. Within Philips many of these technologies are used. However, the discipline of Plasma Physics itself finds its applications in Research for Displays, Lamps and E-UV sources. Those activities are presented.

Given the urgent need to converge on precise guidelines for accident management in nuclear fusion plants, in this paper, the authors will analyze the problem related to the choice of possible candidate materials for the nuclear fusion plants like International Thermonuclear Experimental Reactor (ITER), DEMOnstration power plant (DEMO), or PROTOtype power plant (PROTO). Fusion power is a promising long-term candidate to supply the energy needs of humanity. From the safety point of view, nuclear fusion holds inherent and potential safety advantages over other energy sources. In magnetic confinement devices, the plasma edge and surrounding material surfaces provide a buffer zone between the hightemperature conditions in the plasma core and the normal “terrestrial” environment. The interaction between the plasma edge and the surrounding surfaces profoundly influences the conditions in the plasma core and is the principal key engineering issue. Robust solutions to plasma–material interactions (PMIs) issues are required to realize a commercially attractive fusion reactor. PMIs critically affect tokamak operation in many ways. Erosion by the plasma determines the lifetime of plasma-facing components (PFCs) and generates a source of impurities,which cool and dilute the plasma. Deposition of material onto PFCs alters their surface composition and can lead to long-term accumulation of large in-vessel tritium inventories. Retention and recycling of hydrogen from PFCs affect fueling efficiency, plasma density control, and the density of neutral hydrogen in the plasma boundary, which impacts particle and energy transport. Dusts are currently produced in the existing plants like JET (and will also be in the future ones like ITER, DEMO, and PROTO) by PMIs. Thus, the issues related to the PFCs of the first wall of the nuclear fusion plants area topic that the Quantum Electronics and Plasma Physics Research Group have been studying for more than a decade. Regarding the selection of PFCs, there are two strong school of thoughts that work on fusion plants materials for the first wall: (1) one composed by experts working mainly on nuclear fusion and that are focusing their attention on certain materials (like tungsten, beryllium, carbon, tritium, stainless steel, and other), and (2) the other one composed of experts working mainly on the fission plants that want to demonstrate the “dual-use” characteristics of the “fission materials” for fusion plants applications. In this review paper, the authors will (1) review both the approaches mentioned above comparing the main characteristics of all the proposed and tested materials, (2) analyze the consequences (experimentally revealed and numerically predicted) of PMIs that provokes serious damages to the plants and dangerous consequences like radioactive/toxic dust production, and (3) analyze (also thanks to our experimental activities on STARDUST-Upgrade facility) the risks (for the operators) related to the dust re-suspended in case of accidents. The authors will critically comment each section of the paper together with a detailed state of the art.

"An institution is the lengthened shadow of one man" are perhaps the most appropriate words that can be said about Professor Meghnad Saha and Saha Institute of Nuclear Physics (SINP). Prior to the independence of the country Prof. Saha was working very closely with Jawaharlal Nehru and Subash Chandra Bose in framing the national science and planning policy. He was probably the first person in the country to have foreseen the immense potential of nuclear science for the betterment of Indian society. So by 1940, he introduced nuclear physics as part of the university physics curriculum in the University of Calcutta. With supports from Nehru, he received a generous fund from the Dorabji Tata Trust for the procurement and construction of a cyclotron in 1941. After the World War II and followed by the independence of the country in 1947, Prof. Saha realised that nuclear physics had grown to such an extent that to take part in research a separate institution with a close link to the universities was necessary. Thus, the foundation stone of SINP (the then INP, the Institute of Nuclear Physics) was laid down in 1949 and the institute was formally inaugurated on 11 January 1950, by Madame Irene Joliot Curie. Right from its inception, Prof. Saha initiated research in various disciplines of science ranging from astrophysics, plasma physics, physics of materials and biophysics, in the newly born institute and realising the importance of education, he introduced a post-M.Sc. programme, a pre-Ph.D. course, the first of its kind in the country, to bridge the gap between the university curriculum and research. The institute was renamed as SINP after his untimely demise in 1956.

Wave–particle interactions are central in plasma physics. They can be studied in a traveling wave tube (TWT) to avoid intrinsic plasma noise. This led to detailed experimental analysis of the self-consistent interaction between unstable waves and an either cold or warm beam. More recently a test cold electron beam has been used to observe its non-self-consistent interaction with externally excited wave(s). The velocity distribution function of the electron beam is recorded with a trochoidal energy analyzer at the output of the TWT. An arbitrary waveform generator is used to launch a prescribed spectrum of waves along the slow wave structure (a 4 m long helix) of the TWT. The nonlinear synchronization of particles by a single wave responsible for Landau damping is observed. The resonant velocity domain associated with a single wave is also observed, as well as the transition to large scale chaos when the resonant domains of two waves and their secondary resonances overlap. This transition exhibits a ‘devil's staircase’ behavior when increasing the excitation amplitude in agreement with numerical simulation. A new strategy for control of chaos by building barriers of transport which prevent electrons from escaping from a given velocity region as well as its robustness are successfully tested. The underlying concepts extend far beyond the field of electron devices and plasma physics.

It was with great pleasure that the Department of Nuclear and Theoretical Physics of the University of Pavia and the INFN (Istituto Nazionale di Fisica Nucleare) Structure of Pavia organised the XIX Nuclear Physics Divisional Conference of the European Physical Society, which was held in the historical buildings of the University of Pavia from 5–9 September 2005. The Conference was devoted to the discussion of the most recent experimental and theoretical achievements in the field of Nuclear Physics applications, as well as of the latest developments in technological tools related to Nuclear Physics research. The University of Pavia has a long tradition in Physics and in Applied Physics, being the site where Alessandro Volta developed his "pila", the precursor of the modern battery. This is the place where the first experiments with electricity were conducted and where the term "capacitance" used for capacitors was invented. Today the University hosts a Triga Mark II nuclear reactor, which is used by the Departments of the University of Pavia and by other Universities and private companies as well. Moreover, Pavia is the site selected for the construction of the CNAO complex "Centro Nazionale di Adroterapia Oncologica" (National Centre for Oncological Hadrontherapy), planned for 2005–2008 which represents a unique facility in Italy and will be among the first complexes of this type in Europe.The Conference has gathered together experts in various fields from different countries and has been the occasion to review the present status and to discuss the new emerging trends in Nuclear Physics and its applications to multidisciplinary researches and the development of new technologies. The following topics were treated: Nuclear Techniques in Medicine and Life Sciences (Cancer Therapy, new Imaging and Diagnostics Tools, Radioisotope production, Radiation Protection and Dosimetry). Applications of Nuclear Techniques in Art, Archaeometry and other Interdisciplinary fields. Role of Nuclear Techniques in Environment Problems. Applications of Nuclear Techniques relevant for Civil Security (contraband and explosive detection, search for Weapons of Mass Destruction, Nuclear Safeguards). Nuclear Applications in Space Research. Material and Structure Testing in Research and Industry. New contributions of Nuclear Techniques to the solution of the Energy Production problems and Nuclear Waste Transmutation. Emerging experimental techniques, new detectors and new modeling tools.During the Monday morning Session of the Conference, the 2005 IBA-EUROPHYSICS PRIZE for Applied Nuclear Science and Nuclear Methods in Medicine, sponsored by the Belgian company IBA, was awarded to the two laureates Werner Heil (Mainz) and Pierre Jean Nacher (Paris) for the development of spin polarized 3He targets by optical pumping and their applications in nuclear science and medicine. The meeting was a real success, with 18 invited talks, 66 contributed talks and 31 posters and an overall participation, during five full days, of around 150 scientists from different European and non-European countries. It also hosted a three day industrial exhibition of a selection of Companies that sponsored the event. The Organisers take thos opportunity to thank the University of Pavia, the Amministrazione Comunale di Pavia and the Provincia di Pavia, as well as all exhibitors (Ametek, Ansaldo Superconduttori, Caen, Else, Hamamatsu, IBA, Micos, Micron Semiconductor), for their support of the Conference.The Organisers finally wish to thank the Scientific Secretary of the Conference, Dr Andrea Fontana of INFN Pavia, for the huge amount of work done in preparing the Conference, Mr Claudio Casella of the Department of Nuclear and Theoretical Physics of the University of Pavia for technical support and the Conference staff, Dr Gaia Boghen and the graduate students Federica Devecchi and Silvia Franchino, for their invaluable help. The very effective and professional work of the staff of PRAGMA Congressi, who took charge of all the administrative and accommodation procedures, is also acknowledged. The Local Organizing Committee (Pavia, January 2006)

Brad Gibson1, Igor Kulikov2, Igor Chernykh21University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom2Institute of Computational Mathematics and Mathematical Geophysics SB RAS, 6-th Lavrentyev avenue, Novosibirsk, Russian Federationmhd2019@sscc.ruThe fields of magnetohydrodynamics and plasma physics provide the nexus for a powerful array of multidisciplinary fields. Diverse fundamental and applied topics meet here, ranging from astrophysics, thermonuclear fusion, and earth sciences, through to bleeding-edge mathematical algorithm developments, including particle-in-cell, smoothed particle hydrodynamics, and adaptive mesh refinement approaches, each underpinned by rapid advances in high performance computing technology. The Second Workshop on Numerical Modeling in MHD and Plasma Physics (MHD2019), held 10-11 October 2019 at the Keldysh Institute of Applied Mathematics, in Moscow, brought together 40 leaders in their respective fields, under the guidance of a Program Committee spanning five countries. The overarching goal of the Workshop was the breaking down of artificial barriers which exist between disciplines, in order to share best practice in these diverse fields. By doing so, the associated up-skilling of all the participants could only benefit all those involved, as well as their respective staff and students; the timeliness of such a philosophy should not be underestimated, given the exponential growth in impact of Big Data across all of the disciplines represented at MHD2019. The success of MHD2019 is reflected in the breathtaking array of work highlighted in these proceedings, and bodes well for the continued success of the workshop series in the future.We gratefully acknowledge the financial support of the Budget Project of Institute of Computational Mathematics and Mathematical Geophysics SB RAS No. 0315-2019-0009

John Wesson's well known book, now re-edited for the third time, provides an excellent introduction to fusion oriented plasma physics in tokamaks. The author's task was a very challenging one, for a confined plasma is a complex system characterised by a variety of dimensionless parameters and its properties change qualitatively when certain threshold values are reached in this multi-parameter space. As a consequence, theoretical description is required at different levels, which are complementary: particle orbits, kinetic and fluid descriptions, but also intuitive and empirical approaches. Theory must be carried out on many fronts: equilibrium, instabilities, heating, transport etc. Since the properties of the confined plasma depend on the boundary conditions, the physics of plasmas along open magnetic field lines and plasma surface interaction processes must also be accounted for.Those subjects (and others) are discussed in depth in chapters 2–9. Chapter 1 mostly deals with ignition requirements and the tokamak concept, while chapter 14 provides a list of useful relations: differential operators, collision times, characteristic lengths and frequencies, expressions for the neoclassical resistivity and heat conduction, the bootstrap current etc.The presentation is sufficiently broad and thorough that specialists within tokamak research can either pick useful and up-to-date information or find an authoritative introduction into other areas of the subject. It is also clear and concise so that it should provide an attractive and accurate initiation for those wishing to enter the field and for outsiders who would like to understand the concepts and be informed about the goals and challenges on the horizon. Validation of theoretical models requires adequately resolved experimental data for the various equilibrium profiles (clearly a challenge in the vicinity of transport barriers) and the fluctuations to which instabilities give rise. Chapter 10 is therefore devoted to an introduction to diagnostics for tokamaks.The complexity of fusion plasmas is attested to by the discovery of new phenomena and new operational regimes as machine size and power increased and the diagnostic tools improved over the forty years of research on magnetic confinement. The history of those discoveries in the devices which have been built worldwide after the results obtained on the first tokamaks at the Kurchatov Institute had been confirmed is outlined in chapters 11–12. Particular emphasis is naturally given to the results from the larger tokamaks: ASDEX Upgrade, DIII-D, TFTR, JT-60/JT-60U and JET. Chapter 13 is devoted to the International Tokamak Experimental Reactor and prospects beyond ITER. Examples of operational regimes and of often unexpected phenomena are the linear and saturated ohmic confinement modes, confinement degradation when auxiliary heating is applied, the high energy confinement mode, the formation of internal transport barriers in weak or negative central shear discharges, sawtooth relaxations, disruptions, multifaceted asymmetric radiation from the edge, edge localised modes, etc. The relevant observations are described very thoroughly with the support of numerous selected figures and their physical interpretation, a major topic of the book, is carefully discussed on the basis of simplified but convincing mathematical models.With respect to the previous edition (1997), a few additions have been introduced; those concern plasma rotation (section 3.13), internal transport barriers (4.14), the role of radial electric field shear (4.19), turbulence simulations (4.21), impurity transport (4.22) and neoclassical drive of tearing modes (7.3). It is my personal feeling that some of those additions should have been somewhat more elaborated. A few pages have finally been added concerning the TCV, START, MAST, NSTX and ASDEX Upgrade tokamaks.With this book, John Wesson offers the fusion community a very precious and thorough survey of tokamak physics, from basic principles to interpretation of experimental data, and to a wider readership an elegant and authoritative introduction to the challenges that are associated with the development of the tokamak reactor, a source of limitless and clean thermonuclear power. This reference book should be on the shelf of every fusion scientist and graduate student.