Modélisation d'un réflectomètre mode X en vue de caractériser les fluctuations de densité et de champ magnétique

Modélisation d'un réflectomètre mode X en vue de caractériser les fluctuations de densité et de champ magnétique PDF Author: Muriel Colin
Publisher:
ISBN:
Category :
Languages : fr
Pages : 220

Get Book Here

Book Description
Cette étude porte sur l'interaction entre l'onde sonde et les fluctuations du plasma en réflectométrie dans les plasmas de fusion. Il a été montré qu'une telle interaction, quelle que soit la polarisation de l'onde sonde, peut être décrite par une équation de Mathieu. Pour vérifier la validité du modèle proposé, des codes numériques ont été développés (mode O et mode X). Ces validations étant effectuées, la part respective de l'onde rétrodiffusée par les fluctuations de densité et de champ magnétique a été déterminée, confirmant que les fluctuations de densité sont prépondérantes pour la plupart des situations expérimentales des plasmas de tokamak. Les performances des méthodes numériques développées ont permis les simulations des expériences existantes. La détermination quantitative des perturbations induites par des fluctuations a été effectuée pour des fluctuations cohérentes, et un premier lien entre le spectre des variations de phase et le spectre de la turbulence a été établi.

Modélisation d'un réflectomètre mode X en vue de caractériser les fluctuations de densité et de champ magnétique

Modélisation d'un réflectomètre mode X en vue de caractériser les fluctuations de densité et de champ magnétique PDF Author: Muriel Colin
Publisher:
ISBN:
Category :
Languages : fr
Pages : 220

Get Book Here

Book Description
Cette étude porte sur l'interaction entre l'onde sonde et les fluctuations du plasma en réflectométrie dans les plasmas de fusion. Il a été montré qu'une telle interaction, quelle que soit la polarisation de l'onde sonde, peut être décrite par une équation de Mathieu. Pour vérifier la validité du modèle proposé, des codes numériques ont été développés (mode O et mode X). Ces validations étant effectuées, la part respective de l'onde rétrodiffusée par les fluctuations de densité et de champ magnétique a été déterminée, confirmant que les fluctuations de densité sont prépondérantes pour la plupart des situations expérimentales des plasmas de tokamak. Les performances des méthodes numériques développées ont permis les simulations des expériences existantes. La détermination quantitative des perturbations induites par des fluctuations a été effectuée pour des fluctuations cohérentes, et un premier lien entre le spectre des variations de phase et le spectre de la turbulence a été établi.

Topics in Kinetic Theory

Topics in Kinetic Theory PDF Author: Thierry Passot
Publisher: American Mathematical Soc.
ISBN: 0821837230
Category : Science
Languages : en
Pages : 322

Get Book Here

Book Description
This book covers a variety of topics related to kinetic theory in neutral gases and magnetized plasmas, with extensions to other systems such as quantum plasmas and granular flows. A comprehensive presentation is given for the Boltzmann equations and other kinetic equations for a neutral gas, together with the derivations of compressible and incompressible fluid dynamical systems, and their rigorous justification. Several contributions are devoted to collisionless magnetized plasmas. Rigorous results concerning the well-posedness of the Vlasov-Maxwell system are presented. Special interest is devoted to asymptotic regimes where the scales of variation of the electromagnetic field are clearly separated from those associated with the gyromotion of the particles. This volume collects lectures given at the Short Course and Workshop on Kinetic Theory organized at the Fields Institute of Mathematical Sciences in Toronto during the Spring of 2004.

Ray Tracing and Beyond

Ray Tracing and Beyond PDF Author: E. R. Tracy
Publisher: Cambridge University Press
ISBN: 0521768063
Category : Computers
Languages : en
Pages : 545

Get Book Here

Book Description
This complete introduction to the use of modern ray tracing techniques in plasma physics describes the powerful mathematical methods generally applicable to vector wave equations in non-uniform media, and clearly demonstrates the application of these methods to simplify and solve important problems in plasma wave theory. Key analytical concepts are carefully introduced as needed, encouraging the development of a visual intuition for the underlying methodology, with more advanced mathematical concepts succinctly explained in the appendices, and supporting Matlab and Raycon code available online. Covering variational principles, covariant formulations, caustics, tunnelling, mode conversion, weak dissipation, wave emission from coherent sources, incoherent wave fields, and collective wave absorption and emission, all within an accessible framework using standard plasma physics notation, this is an invaluable resource for graduate students and researchers in plasma physics.

X-Ray and Neutron Reflectivity: Principles and Applications

X-Ray and Neutron Reflectivity: Principles and Applications PDF Author: Jean Daillant
Publisher: Springer Science & Business Media
ISBN: 3540486968
Category : Science
Languages : en
Pages : 347

Get Book Here

Book Description
The reflection of and neutrons from surfaces has existed as an x-rays exp- imental for almost it is in the last technique fifty Nevertheless, only years. decade that these methods have become as of enormously popular probes This the surfaces and interfaces. to be due to of several appears convergence of intense different circumstances. These include the more n- availability be measured orders tron and sources that can over (so reflectivity x-ray many of and the much weaker surface diffuse can now also be magnitude scattering of thin films and studied in some the detail); growing importance multil- basic the realization of the ers in both and technology research; important which in the of surfaces and and role roughness plays properties interfaces; the of statistical models to characterize the of finally development topology its and its characterization from on roughness, dependence growth processes The of and to surface scattering experiments. ability x-rays neutro4s study four five orders of in scale of surfaces over to magnitude length regardless their and also their to ability probe environment, temperature, pressure, etc. , makes these the choice for buried interfaces often probes preferred obtaining information about the microstructure of often in statistical a global surfaces, the local This is manner to complementary imaging microscopy techniques, of such studies in the literature witnessed the veritable by explosion published the last few Thus these lectures will useful for over a resource years.

Whistlers and Related Ionospheric Phenomena

Whistlers and Related Ionospheric Phenomena PDF Author: Robert A. Helliwell
Publisher: Courier Corporation
ISBN: 0486151212
Category : Technology & Engineering
Languages : en
Pages : 370

Get Book Here

Book Description
The investigation of whistlers and related phenomena is a key element in studies of very-low-frequency propagation, satellite communication, the outer ionosphere, and solar-terrestrial relationships. This comprehensive text presents a history of the study of the phenomena and includes all the elements necessary for the calculation of the characteristics of whistlers and whistler-mode signals. An introduction and brief history are followed by a summary of the theory of whistlers and a detailed explanation of the calculation of their characteristics. Succeeding chapters offer a complete atlas of a variety of whistlers, including those observed in satellites and those generated by nuclear explosions; the results of satellite observation of whistler-mode propagation; the method of reducing whistler data and obtaining electron density information; a full atlas of the various kinds of emissions; and an outline and comparison of the theories of generation of emissions.

Historical Dictionary of Iran

Historical Dictionary of Iran PDF Author: John Henry Lorentz
Publisher: Historical Dictionaries of Asia, Oceania, and the Middle East
ISBN:
Category : History
Languages : en
Pages : 570

Get Book Here

Book Description
Provides an overview of specific events, movements, people, political and social groups, places, trends, and chronology. Allows for considerable exploration of a number of historical and contemporary topics and issues. The modern period, defined as 1800-present, is covered extensively.

Beam Instrumentation and Diagnostics

Beam Instrumentation and Diagnostics PDF Author: Peter Strehl
Publisher: Springer Science & Business Media
ISBN: 3540264043
Category : Science
Languages : en
Pages : 438

Get Book Here

Book Description
This book summarizes the experience of many years of teamwork with my group, the beam diagnostics group of GSI. For a long time the group was also responsible for operating the machines and application programming. In my opinion, this connection was very e?cient: ?rst, because a beam diagnostic system has to place powerful tools at the operators’ disposal; second, because data evaluation and presentation of results for machine operation demand application programs which can be handled not only by skilled experts. On the other hand, accelerator developments and improvements as well as commissioning of new machines by specialists require more complex measu- ments than those for routine machine operation. A modern beam diagnostic system, including the software tools, has to cover these demands, too. Therefore, this book should motivate physicists, constructors, electronic engineers, and computer experts to work together during the design and daily use of a beam diagnostic system. This book aims to give them ideas and tools for their work. I would not have been able to write this book without a good education in physics and many discussions with competent leaders, mentors, and c- leagues. After working about 40 years in teams on accelerators, there are so many people I have to thank that it is impossible to mention them all by name here.

Lecture Notes on Beam Instrumentation and Diagnostics

Lecture Notes on Beam Instrumentation and Diagnostics PDF Author: Peter Forck
Publisher:
ISBN: 9781506171487
Category :
Languages : en
Pages : 154

Get Book Here

Book Description
Lecture Notes on Beam Instrumentation and DiagnosticsBy Peter Forck

Historical Dictionary of Pakistan

Historical Dictionary of Pakistan PDF Author: Shahid Javed Burki
Publisher:
ISBN:
Category : History
Languages : en
Pages : 472

Get Book Here

Book Description
Pakistan is unlike most other countries in the emerging world. It is one of the two nations – the other being the state of Israel – founded on the basis of religion. Although it was created to provide a homeland for the Muslim community of British India, in its original form it was able to accommodate only about half of the people of Islamic faith who lived in the subcontinent. Pakistan’s birth in 1947 resulted in one of the largest movements of people in human history when some 14 million people left their homes, with 8 million Muslims leaving India for what is now Pakistan and 6 million Hindus and Sikhs moving in the opposite direction. This was the first large-scale incidence of ethnic cleansing the world was to witness. --