Linear studies of spurious backward-wave instabilities in a dielectric-loaded smooth-wall gyrotron beam ducts

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Nuclear fusion power plants require electron cyclotron (EC) heating and current drive (H&CD) systems for plasma heating and stabilization. High-power microwave beams between 1 and 2?MW generated by gyrotrons propagate in a dedicated waveguide transmission ...

In many tokamak and stellarator experiments around the globe that arc investigating energy production via controlled thermonuclear fusion, electron cyclotron heating and current drive (ECH&CD) are used for plasma start-up, heating, non-inductive current dr ...

In this paper, we report a fully stretchable liquid metal based sensor system for compliance detection. The system is composed of a strain sensor layer, a gap layer with a hole in the center and a pressure sensor layer from top to bottom. Inspired from the ...

Gyrotron R&D within the EUROfusion Work Package Heating and Current Drive (WPHCD) is addressing the challenging requirements posed on gyrotrons by the European concept for a demonstration fusion power plant (EU DEMO). These requirements, as specified withi ...

Detailed understanding of the poisoning mechanism in Diesel oxidation catalysts (DOCs) is the key to prevent long term catalyst deterioration in vehicles. The present work studies artificial phosphorus (P) poisoning methods applied to a commercial DOC. Cor ...

In Europe, the research and development with main focus on achieving robust industrial designs of series gyrotrons for electron cyclotron heating and current drive of today's nuclear fusion experiments and towards a future DEMOnstration fusion power plant ...

With the emergence of more and more torque-controlled robots, the agility of leg locomotion has been promoted to a new level, which, however, seems also to imply that only torque-controlled robots are appropriate for leg locomotion. This paper demonstrates ...

The EC-system of the TCV tokamak is progressively being upgraded with the addition of two MW-class dual-frequency gyrotrons (84 and 126 GHz/2s/1MW). In order to connect the two gyrotrons to the existing low field side and top launchers, new waveguide routi ...

This paper proposes a shape optimization algorithm based on the principles of Isogeometric Analysis (IGA) in which the parameterization of the geometry enters the problem formulation as an additional PDE-constraint. Inspired by the isoparametric principle ...

Resonant waveguide gratings (RWGs), also known as guided mode resonant (GMR) gratings or waveguide-mode resonant gratings, are dielectric structures where these resonant diffractive elements benefit from lateral leaky guided modes and can operate from UV t ...

Although reinforced concrete U-shaped walls are popular in construction practice internationally, there is a paucity of experimental research investigating the seismic performance of such salient elements. The present paper summarizes an experimental campa ...

This paper explores the concept of dissipative exposed column base connections by means of anchor rod yielding. This concept aims at enhancing the seismic performance of low-rise steel moment-resisting frames (MRFs). A mechanics-based model is proposed tha ...

In order to study parasitic oscillation that may occur in a realistic beam duct upstream to the gyrotron cavity, the self-consistent linear and spectral code TWANGlinspec has been modified. The large inhomogeneities in the smooth-wall beam duct geometry or ...

Recently developed self-consistent models for beam-wave interaction simulations of a gyrotron oscillator are used to study spurious backward-wave instabilities in smooth-wall metallic beam ducts. Starting from a simple case with a basic geometry, the influ ...

Conventional conductive films that are used as electrodes in organic thin film transistors (OTFTs) are susceptible to mechanical deformation, limiting the applicability of such films in flexible wearable electronic devices. To address this limitation, a hy ...

On ITER, long pulse gyrotrons are required as a power source for electron cyclotron heating (ECH) and current drive (CD). The microwaves are guided from the gyrotrons, which are placed far from the Tokamak, into the plasma by transmission lines (TLs) and a ...

A biosensor device including a metal layer, a transparent substrate layer, and a dielectric layer, wherein the metal layer includes a plurality of sub-wavelength apertures, and wherein the dielectric layer is located between the metal layer and the transpa ...

Raw exhaust gases may contain notable levels of formaldehyde that can negatively impact the efficiency of after -treatment systems. In the selective catalytic reduction (SCR) of NOx over V2O5/WO3-TiO2, formaldehyde was found to react with NH3 to produce HC ...

Isolation of a system from its environment is often desirable, from precision measurements to control of individual quantum systems; however, dissipation can also be a useful resource. Remarkably, engineered dissipation enables the preparation of quantum s ...

With the aim of gaining a better physical insight into linear regimes in gyrotrons, a new linear model was developed. This model is based on a spectral approach for solving the self-consistent system of equations describing the wave-particle interaction in ...

Linear studies of spurious backward-wave instabilities in a dielectric-loaded smooth-wall gyrotron beam ducts

Chat with Graph Search

Diamond Window Technology for Electron Cyclotron Heating and Current Drive: State of the Art

High-power gyrotrons for electron cyclotron heating and current drive

Bioinspired Liquid Metal Based Sensing System For Compliance Detection

Overview of recent gyrotron R&D towards DEMO within EUROfusion Work Package Heating and Current Drive

Understanding the impact of poison distribution on the performance of Diesel oxidation catalysts

From W7-X Towards ITER and Beyond: 2019 Status on EU Fusion Gyrotron Developments

A Position-Control-Based Framework for Dynamic and Robust Quadrupedal Trotting

Design and implementation of quasi-optical components for the upgrade of the TCV EC-system

The role of PDE-based parameterization techniques in gradient-based IGA shape optimization applications

Resonant Waveguide Gratings for Color-Selective Diffraction

RC U-shaped walls subjected to in-plane, diagonal, and torsional loading: New experimental findings

Anchor-yield exposed column bases for minimizing residual deformations in seismic-resistant steel moment frames

Parasitic Oscillations in Smooth-Wall Circular Symmetric Gyrotron Beam Ducts

Linear and non-linear studies of spurious backward-wave instabilities in a smooth-wall gyrotron beam duct

Sequential manufacturing via intra-additive hybrid materials approach for fully roll-to-roll processed flexible organic thin film transistors

Prototype mitre bends of the ex-vessel waveguide system for the ITER upper launcher: Thermal hydraulic simulations and experiments with off-center mm-wave beams

Plasmonic Nanohole Arrays on Hybrid Substrate For Highly Sensitive Label-Free Biosensing

HCN production from formaldehyde during the selective catalytic reduction of NOx with NH3 over V2O5/WO3-TiO2

A dissipative quantum reservoir for microwave light using a mechanical oscillator

Novel linear analysis for a gyrotron oscillator based on a spectral approach