다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The ITER Physics Basis presents and evaluates the physics rules and methodologies for plasma performance projections, which provide the basis for the design of a tokamak burning plasma device whose goal is to demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes. This Chapter summarizes the physics basis for burning plasma projections, which is developed in detail by the ITER Physics Expert Groups in subsequent chapters. To set context, the design guidelines and requirements established in the report of ITER Special Working Group 1 are presented, as are the specifics of the tokamak design developed in the Final Design Report of the ITER Engineering Design Activities, which exemplifies burning tokamak plasma experiments. The behaviour of a tokamak plasma is determined by the interaction of many diverse physics processes, all of which bear on projections for both a burning plasma experiment and an eventual tokamak reactor. Key processes summarized here are energy and particle confinement and the H-mode power threshold; MHD stability, including pressure and density limits, neoclassical islands, error fields, disruptions, sawteeth, and ELMs; power and particle exhaust, involving divertor power dispersal, helium exhaust, fuelling and density control, H-mode edge transition region, erosion of plasma facing components, tritium retention; energetic particle physics; auxiliary power physics; and the physics of plasma diagnostics. Summaries of projection methodologies, together with estimates of their attendant uncertainties, are presented in each of these areas. Since each physics element has its own scaling properties, an integrated experimental demonstration of the balance between the combined processes which obtains in a reactor plasma is inaccessible to contemporary experimental facilities: it requires a reactor scale device. It is argued, moreover, that a burning plasma experiment can be sufficiently flexible to permit operation in a steady state mode, with non-inductive plasma current drive, as well as in a pulsed mode where current is inductively driven. Overall, the ITER Physics Basis can support a range of candidate designs for a tokamak burning plasma facility. For each design, there will remain a significant uncertainty in the projected performance, but the projection methodologies outlined here do suffice to specify the major parameters of such a facility and form the basis for assuring that its phased operation will return sufficient information to design a prototype commercial fusion power reactor, thus fulfilling the goal of the ITER project.

https://iopscience.iop.org/article/10.1088/0029-5515/39/12/301/pdf

Chapter 1: Overview and summary

Nonlinear gyrokinetic equations play a fundamental role in our understanding of the long-time behavior of strongly magnetized plasmas. The foundations of modern nonlinear gyrokinetic the- ory are based on three important pillars: (1) a gyrokinetic Vlasov equation written in terms of a gyrocenter Hamiltonian with quadratic low-frequency ponderomotive-like terms; (2) a set of gyrokinetic Maxwell (Poisson-Ampere) equations written in terms of the gyrocenter Vlasov dis- tribution that contain low-frequency polarization (Poisson) and magnetization (Ampere) terms derived from the quadratic nonlinearities in the gyrocenter Hamiltonian; and (3) an exact energy conservationlaw for the gyrokineticVlasov-Maxwell equations that includes all the relevant linear and nonlinear coupling terms. The foundations of nonlinear gyrokinetic theory are reviewed with an emphasis on the rigorous applications of Lagrangian and Hamiltonian Lie-transform perturba- tion methods used in the variationalderivationof nonlineargyrokineticVlasov-Maxwell equations. The physical motivations and applications of the nonlinear gyrokinetic equations, which describe the turbulent evolution of low-frequency electromagnetic fluctuations in a nonuniform magnetized plasmas with arbitrary magnetic geometry, are also discussed.

/pdf/foundations-of-nonlinear-gyrokinetic-theory-3l78lnlpai.pdf

Foundations of nonlinear gyrokinetic theory

http://www.xsciforge.com/about/articles/nubeam.pdf

The tokamak Monte Carlo fast ion module NUBEAM in the National Transport Code Collaboration library

Low-temperature plasma physics and technology are diverse and interdisciplinary fields. The plasma parameters can span many orders of magnitude and applications are found in quite different areas of daily life and industrial production. As a consequence, the trends in research, science and technology are difficult to follow and it is not easy to identify the major challenges of the field and their many sub-fields. Even for experts the road to the future is sometimes lost in the mist. Journal of Physics D: Applied Physics is addressing this need for clarity and thus providing guidance to the field by this special Review article, The 2012 Plasma Roadmap.

/pdf/the-2012-plasma-roadmap-3pk2a2bghd.pdf

The 2012 Plasma Roadmap

In JET discharges with high-power ICRH and a central safety factor lower than unity, monster sawtooth crashes are preceeded by so called tornado modes [1], see figure 1 (left), observed experimentally using both external Mirnov coils and interferometry diagnostics. These modes, with frequencies in the toroidal Alfven eigenmode (TAE) range, appear with decreasing toroidal mode numbers one by one and they exhibit a peculiar downward sweep in frequency, initially deviating from the usual TAE scaling fTAE ∝ B/ √ n. Moreover, the tornado modes appear simultaneaously with a decrease in the intensity of γ-rays emitted from hot ions in the plasma center, implying that the tornado modes are responsible for a reduction of the hot ion population inside the q = 1 magnetic surface, and that this redistribution may in fact be the cause of the monster sawtooth crashes. O-mode interferometry reveals another interesting feature of the magnetic spectrum on JET: The tornado modes are often preceeded by a set of core-localized modes in the range 50− 200 kHz. These modes behave similar to Alfven cascades (ACs) in reversed-shear plasmas [2], in that their frequencies sweep up more or less linearly in time, seemingly from the same initial frequency but with different sweeping rates. Similar modes have been observed on the Alcator C-Mod tokamak using phase constrast imaging diagnostics [3].

http://publications.lib.chalmers.se/records/fulltext/131381/local_131381.pdf

Fast Ion Driven Alfvén Eigenmodes within the q=1 Radius

Development of Alfven spectroscopy in advanced scenarios on JET

This work addresses one-dimensional evolution of a collisionless plasma next to a solid surface that is immersed into the plasma instantaneously. In particular, we consider how the self-similar rarefaction wave (Allen & Andrews, J. Plasma Phys., vol. 4, 1970, pp. 187–194) establishes dynamically and how the electron reflection from the surface modifies the structure of the rarefaction wave and the Debye sheath. We demonstrate that a sufficiently strong reflection eliminates the Debye sheath and changes the wall potential and the plasma flow parameters significantly. The paper presents numerical results that illustrate the developed analytical theory.

/pdf/plasma-sheath-and-presheath-development-near-a-partially-1kor0aadyf.pdf

Plasma sheath and presheath development near a partially reflective surface

http://absimage.aps.org/image/DPP07/MWS_DPP07-2007-000062.pdf

Boris Breizman

Papers

Fast Ion Driven Alfvén Eigenmodes within the q=1 Radius

Development of Alfven spectroscopy in advanced scenarios on JET

Plasma sheath and presheath development near a partially reflective surface

Magnetic Nozzle and Plasma Detachment Scenario

Alpha particle effects on global MHD modes, and alpha particle transport in ignited tokamaks