› › Time Dependent Spectrum Analysis Of High Power Gyrotrons

Time-dependent spectrum analysis of high power gyrotrons

Author : Schlaich, Andreas

Publisher : KIT Scientific Publishing

Page : 316 pages

File Size : 33,88 MB

Release : 2015-08-06

Category : Technology (General)

ISBN : 3731503751

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Book Description

In this work, a novel measurement system for the analysis of the gyrotron RF output spectrum was developed. It enables unprecedented time dependent measurements within a large bandwidth, dynamic range and unambiguous RF indication in the entire D-Band (110-170 GHz). Special attention was given to the investigation of parasitic RF oscillations, and the analysis of the interplay of thermal cavity expansion and ionization-based space charge neutralization at the start of long RF pulses.



Temperature- and Time-Dependent Dielectric Measurements and Modelling on Curing of Polymer Composites

Author : Prastiyanto, Dhidik

Publisher : KIT Scientific Publishing

Page : 204 pages

File Size : 25,13 MB

Release : 2016-03-15

Category : Dielectric measurements

ISBN : 3731504243

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Book Description

In this book a test set for dielectric measurements at 2.45 GHz during curing of polymer composites is developed. Fast reconstruction is solved using a neural network algorithm. Modeling of the curing process at 2.45 GHz using both dielectric constant and dielectric loss factor results in more accurate model compared to low frequency modelling that only uses the loss factor. Effect of various hardeners and different amount of filler is investigated.



Systematic Study of Key Components for a Coaxial-Cavity Gyrotron for DEMO

Author : Franck, Joachim

Publisher : KIT Scientific Publishing

Page : 274 pages

File Size : 32,34 MB

Release : 2017-05-11

Category : Technology (General)

ISBN : 3731506521

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Book Description

The physical design of cavity and magnetron injection gun (MIG) for a realistic, DEMO-compatible, coaxial-cavity 238 GHz 2 MW CW fusion gyrotron is developed in this work, having auxiliary frequencies at 170 GHz and 204 GHz. Novel systematic approaches towards multi-frequency mode selection, magnet requirements, and MIG design are presented. Mode deterioration and voltage depression variation due to insert misalignment versus cavity wall and/or versus electron beam are studied.





A First 2 MW-Class (136)/170/204 GHz Multi-Frequency Gyrotron Pre-Prototype for DEMO: Design, Construction and Key Components Verification

Author : Ruess, Tobias

Publisher : KIT Scientific Publishing

Page : 258 pages

File Size : 48,16 MB

Release : 2023-10-26

Category :

ISBN : 3731513099

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Book Description

Ein Gyrotron wird in magnetisch eingeschlossenen Plasmaexperimenten für Heizung, Stromtrieb, Plasmastabilisierung und Plasmadiagnostik verwendet. In dieser Arbeit wird der erste Entwurf und Bau eines Mehrfrequenz-/Mehrzweck Pre-Prototyp Gyrotrons in koaxialer Technologie vorgestellt, das bei (136)/170/204 GHz mit einer Ausgangsleistung von 2 MW arbeitet. Dies ist der erste Schritt zum Betrieb bei Frequenzen bis zu 240 GHz unter Verwendung der Koaxialhohlraum-Gyrotrontechnologie. - A gyrotron is used in magnetically confined plasma experiments for heating, current drive, plasma stabilization and plasma diagnostics. This work presents the first design and construction of a multi-frequency / multi-purpose coaxial-cavity pre-prototype gyrotron operating at (136)/170/204 GHz with an output power of 2 MW. It is the first step towards operating frequencies up to 240 GHz using the coaxial-cavity gyrotron technology.



Energy-efficient, scalable and modular industrial microwave applicator for high temperature alkaline hydrolysis of PET

Author : Ramopoulos, Vasileios

Publisher : KIT Scientific Publishing

Page : 162 pages

File Size : 13,32 MB

Release : 2023-01-27

Category : Technology & Engineering

ISBN : 3731510995

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Book Description

Microwave-assisted alkaline hydrolysis of PET can be 20 times faster and at lower temperatures. This work presents a novel industrial microwave applicator at 2.45 GHz with homogeneous distribution to support this reaction, which allows an efficient and continuous operation. In addition, an innovative dielectric and calorimetric measurements setup is presented. Furthermore, the modelling of the reaction kinetics based on the measured dielectric parameters is presented.



Automated Mode Recovery and Electronic Stability Control for Wendelstein 7-X Gyrotrons

Author : Wilde, Fabian

Publisher : KIT Scientific Publishing

Page : 272 pages

File Size : 48,75 MB

Release : 2024-08-07

Category :

ISBN : 3731511606

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Book Description

Magnetic confinement fusion relies on plasma heating and plasma control using gyrotron oscillators providing at megawatt power levels. The operational reliability decreases when operating at the performance limits due to increasing parasitic mode activity. This work demonstrates for the first time the automated, fast recovery of nominal gyrotron operation during a pulse by exploiting the hysteretic gyrotron behaviour after a mode switch being in use at the Wendelstein 7-X ECRH facility.



Influence of Emitter Surface Roughness and Emission Inhomogeneity on Efficiency and Stability of High Power Fusion Gyrotrons

Author : Zhang, Jianghua

Publisher : KIT Scientific Publishing

Page : 226 pages

File Size : 40,29 MB

Release : 2016-11-30

Category : Technology (General)

ISBN : 3731505789

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Book Description

The increasing demand for powerful, reliable, and efficient gyrotron oscillators for Electron Cyclotron Resonance Heating (ECRH) in fusion plasma experiments requires a close look at the various factors in gyrotrons that determine gyrotron performance. In this frame, the influence of emitter surface roughness, emission inhomogeneity, and secondary electron generation on gyrotron operation is presented, with focus on Low Frequency Oscillations (LFOs) and Electron Beam Halo (EBH) generation.



Feasibility and Operational Limits for a 236 GHz Hollow-Cavity Gyrotron for DEMO

Author : Kalaria, Parth Chandulal

Publisher : KIT Scientific Publishing

Page : 270 pages

File Size : 11,32 MB

Release : 2017-11-08

Category : Technology (General)

ISBN : 373150717X

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Book Description

The DEMOnstration fusion power plant (DEMO) will be the first fusion reactor, which is intended to generate net electrical power. For successful operation of DEMO, high-power gyrotrons with operating frequencies up to 240 GHz are required for plasma heating and stabilization. In this work, a systematic feasibility study and tolerance analysis are performed for the conventional-type hollow-cavity DEMO gyrotrons. The various approaches are also suggested to identify its operational limits.