Design and Operation of Antennas at the Ion Cyclotron and Lower Hybrid Range of Frequencies for Nuclear Fusion Reactors

Design and Operation of Antennas at the Ion Cyclotron and Lower Hybrid Range of Frequencies for Nuclear Fusion Reactors PDF Author: Walid Helou
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The thesis provides at first a brief introduction to magnetic nuclear fusion and tokamaks. It explains the need for auxiliary plasma heating and current-drive electromagnetic systems at the Ion Cyclotron and Lower Hybrid Range of Frequencies (ICRF and LHRF). The thesis then sets antenna specifications that allow satisfying proper plasma wave propagation and proper wave-particle resonance. The Radio Frequency (RF) network solver SIDON developed for this thesis is then presented. The thesis then discusses the different types of ICRF antennas and details the challenges of the impedance matching in ICRF arrays of straps. WEST ICRF launchers are discussed in great detail and simulations of impedance matching scenarios for these launchers using SIDON are reported. The thesis reports on the low-power (milliwatt range) testbed that has been developed for WEST ICRF launchers, as well as the low-power tests of the first one among them. Furthermore, high power (megawatt range) experiments on plasma with the JET ICRF ITER-Like Antenna are reported. The thesis then provides an overview about existing LHRF antennas and discusses the numerical modeling of the coupling of waveguide phased arrays to the plasma. The RF design of ASTARTE-LP and its feeding circuit is discussed. ASTARTE-LP is a low-power (milliwatt range) prototype LHRF antenna based on the Slotted Waveguide Antenna concept that has been designed and built to perform proof of principle experiments on the COMPASS tokamak. The experimental validation of ASTARTE-LP and its feeding circuit before the experiments on COMPASS, as well as the experiments performed on COMPASS plasmas are reported.

Design and Operation of Antennas at the Ion Cyclotron and Lower Hybrid Range of Frequencies for Nuclear Fusion Reactors

Design and Operation of Antennas at the Ion Cyclotron and Lower Hybrid Range of Frequencies for Nuclear Fusion Reactors PDF Author: Walid Helou
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The thesis provides at first a brief introduction to magnetic nuclear fusion and tokamaks. It explains the need for auxiliary plasma heating and current-drive electromagnetic systems at the Ion Cyclotron and Lower Hybrid Range of Frequencies (ICRF and LHRF). The thesis then sets antenna specifications that allow satisfying proper plasma wave propagation and proper wave-particle resonance. The Radio Frequency (RF) network solver SIDON developed for this thesis is then presented. The thesis then discusses the different types of ICRF antennas and details the challenges of the impedance matching in ICRF arrays of straps. WEST ICRF launchers are discussed in great detail and simulations of impedance matching scenarios for these launchers using SIDON are reported. The thesis reports on the low-power (milliwatt range) testbed that has been developed for WEST ICRF launchers, as well as the low-power tests of the first one among them. Furthermore, high power (megawatt range) experiments on plasma with the JET ICRF ITER-Like Antenna are reported. The thesis then provides an overview about existing LHRF antennas and discusses the numerical modeling of the coupling of waveguide phased arrays to the plasma. The RF design of ASTARTE-LP and its feeding circuit is discussed. ASTARTE-LP is a low-power (milliwatt range) prototype LHRF antenna based on the Slotted Waveguide Antenna concept that has been designed and built to perform proof of principle experiments on the COMPASS tokamak. The experimental validation of ASTARTE-LP and its feeding circuit before the experiments on COMPASS, as well as the experiments performed on COMPASS plasmas are reported.

Design and Control of Phased ICRF Antenna Arrays

Design and Control of Phased ICRF Antenna Arrays PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
Phased antenna arrays operating in the ion cyclotron range of frequencies (ICRF) are used to produce highly directional wave spectra, primarily for use in current drive experiments. RF current drive using phased antennas has been demonstrated in both the JET and DIII-D tokamaks, and both devices are planning to operate new four-element arrays beginning early next year. Features of antenna design that are relevant to phased operation and production of directional spectra are reviewed. Recent advances in the design of the feed circuits and the related control systems for these arrays should substantially improve their performance, by reducing the coupling seen by the matching networks and rf power supplies caused by the mutual impedance of the array elements. The feed circuit designs for the DIII-D and JET phased antenna arrays are compared. The two configurations differ significantly due to the fact that one power amplifier is used for the entire array in the former case, and one per element in the latter. The JET system uses automatic feedback control of matching, phase and amplitude of antenna currents, and the transmitter power balance. The design of this system is discussed, and a time dependent model used to predict its behavior is described.

Fusion Energy Update

Fusion Energy Update PDF Author:
Publisher:
ISBN:
Category : Controlled fusion
Languages : en
Pages : 72

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Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 472

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Antennas for the Radio Frequency Heating of Plasmas on Fusion Research Devices in the Ion Cyclotron Range of Frequencies

Antennas for the Radio Frequency Heating of Plasmas on Fusion Research Devices in the Ion Cyclotron Range of Frequencies PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Three-dimensional Antenna Models for Fusion Experiments

Three-dimensional Antenna Models for Fusion Experiments PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
The development of the RANT3D code has permitted the systematic study Of the effect of three-dimensional structures on the launched power spectrum for antennas in the ion cyclotron range of frequencies. The code allows the septa between current straps to be modeled with arbitrary heights and permits the antenna to interact with other structures in the tokamak. In this paper we present comparisons of calculated loading with the Tokamak Fusion Test Reactor and Tore Supra experiments, demonstrate the effects on loading caused by positioning uncertainties for an antenna in Tore Supra, and show electric field patterns near the Tore Supra antenna. A poloidal component in the static magnetic field for the plasma response is included in the near-field calculations using the warm plasma code, GLOSI. Preliminary estimates for the heat flux on the bumper limiters during typical operation in Tore Supra are also presented.

Chemical Abstracts

Chemical Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2018

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Reflectarray Antennas

Reflectarray Antennas PDF Author: Payam Nayeri
Publisher: John Wiley & Sons
ISBN: 1118846753
Category : Technology & Engineering
Languages : en
Pages : 729

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Book Description
This book provides engineers with a comprehensive review of the state-of-the-art in reflectarray antenna research and development. The authors describe, in detail, design procedures for a wide range of applications, including broadband, multi-band, multi-beam, contour-beam, beam-scanning, and conformal reflectarray antennas. They provide sufficient coverage of basic reflectarray theory to fully understand reflectarray antenna design and analysis such that the readers can pursue reflectarray research on their own. Throughout the book numerous illustrative design examples including numerical and experimental results are provided. Featuring in-depth theoretical analysis along with practical design examples, em style="mso-bidi-font-style: normal;"Reflectarray Antennas is an excellent text/reference for engineering graduate students, researchers, and engineers in the field of antennas. It belongs on the bookshelves of university libraries, research institutes, and industrial labs and research facilities.

Terahertz Planar Antennas for Next Generation Communication

Terahertz Planar Antennas for Next Generation Communication PDF Author: Kumud Ranjan Jha
Publisher: Springer Science & Business Media
ISBN: 3319023411
Category : Technology & Engineering
Languages : en
Pages : 221

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Book Description
This book describes various methods to enhance the directivity of planar antennas, enabling the next generation of high frequency, wireless communication. The authors discuss various applications to the terahertz regime of the electromagnetic spectrum, with an emphasis on gain enhancement mechanisms. The numerical models of these antennas are presented and the analytical results are supported, using commercial simulators. The multilayer substrate microstrip transmission line at terahertz frequency is also explored and a method to obtain the various parameters of this interconnect at high frequency is described. This book will be a valuable resource for anyone needing to explore the terahertz band gap for future wireless communication, in an effort to solve the bandwidth (spectrum scarcity) problem.

Nuclear Fusion

Nuclear Fusion PDF Author:
Publisher:
ISBN:
Category : Nuclear fusion
Languages : en
Pages : 1102

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