Global and pedestal confinement in JET with a Be/W metallic wall

2014 ◽  
Vol 54 (4) ◽  
pp. 043001 ◽  
Author(s):  
M.N.A. Beurskens ◽  
L. Frassinetti ◽  
C. Challis ◽  
C. Giroud ◽  
S. Saarelma ◽  
...  
Keyword(s):  
Metallic Wall

scholarly journals On the challenge of plasma heating with the JET metallic wall

2014 ◽  
Vol 54 (3) ◽  
pp. 033002 ◽  
Author(s):  
M.-L. Mayoral ◽  
V. Bobkov ◽  
A. Czarnecka ◽  
I. Day ◽  
A. Ekedahl ◽  
...  
Keyword(s):  
Plasma Heating ◽  
Metallic Wall

scholarly journals Analytic study on low- external ideal infernal modes in tokamaks with large edge pressure gradients

2018 ◽  
Vol 84 (2) ◽  
Author(s):  
Daniele Brunetti ◽  
J. P. Graves ◽  
E. Lazzaro ◽  
A. Mariani ◽  
S. Nowak ◽  
...  
Keyword(s):  
Dispersion Relation ◽  
Safety Factor ◽  
Mass Density ◽  
Analytic Study ◽  
Pressure Gradients ◽  
Plasma Edge ◽  
Vacuum Region ◽  
Metallic Wall ◽  
Equilibrium Profiles ◽  
Pressure Driven

The problem of pressure driven infernal type perturbations near the plasma edge is addressed analytically for a circular limited tokamak configuration which presents an edge flattened safety factor. The plasma is separated from a metallic wall, either ideally conducting or resistive, by a vacuum region. The dispersion relation for such types of instabilities is derived and discussed for two classes of equilibrium profiles for pressure and mass density.

scholarly journals Microwave Differential Frequency Splitting Sensor Using Magnetic-LC Resonators

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1066 ◽  
Author(s):  
Amir Ebrahimi ◽  
Grzegorz Beziuk ◽  
James Scott ◽  
Kamran Ghorbani
Keyword(s):  
Dielectric Properties ◽  
Transmission Line ◽  
Reference Sample ◽  
Solid Materials ◽  
Microstrip Transmission Line ◽  
Frequency Splitting ◽  
Metallic Wall ◽  
Lc Resonator ◽  
Lc Resonators

A differential microwave permittivity sensor and comparator is designed using a microstrip transmission line loaded with a magnetic-LC resonator. The microstrip transmission line is aligned with the electric wall of the resonator. The sensor shows a single transmission zero, when it is unloaded or loaded symmetrically on both halves. A second notch appears in the transmission response by asymmetrical dielectric loading on the two halves of the device. The frequency splitting is used to characterize the dielectric properties of the samples under test. The sensitivity of the sensor is enhanced by removing the mutual coupling between the two halves of the magnetic-LC resonator using a metallic wall. The sensors’ operation principle is explained through a circuit model analysis. A prototype of the designed sensor is fabricated and measurements are used for validation of the sensing concept. The sensor can be used for determination of the dielectric properties in solid materials or detecting defects and impurities in solid materials through a comparative measurement with a reference sample.

scholarly journals Electrostatic interactions between ions near Thomas–Fermi substrates and the surface energy of ionic crystals at imperfect metals

2017 ◽  
Vol 199 ◽  
pp. 129-158 ◽  
Author(s):  
V. Kaiser ◽  
J. Comtet ◽  
A. Niguès ◽  
A. Siria ◽  
B. Coasne ◽  
...  
Keyword(s):  
Surface Energy ◽  
Electrostatic Interactions ◽  
Electrostatic Energy ◽  
Screening Length ◽  
Thomas Fermi ◽  
Electronic Screening ◽  
Ionic Systems ◽  
Metallic Wall ◽  
Electrostatic Contribution ◽  
Dimensional Crystal

The electrostatic interaction between two charged particles is strongly modified in the vicinity of a metal. This situation is usually accounted for by the celebrated image charges approach, which was further extended to account for the electronic screening properties of the metal at the level of the Thomas–Fermi description. In this paper we build upon a previous approach [M. A. Vorotyntsev and A. A. Kornyshev, Zh. Eksp. Teor. Fiz., 1980, 78(3), 1008–1019] and successive works to calculate the 1-body and 2-body electrostatic energy of ions near a metal in terms of the Thomas–Fermi screening length. We propose workable approximations suitable for molecular simulations of ionic systems close to metallic walls. Furthermore, we use this framework to calculate analytically the electrostatic contribution to the surface energy of a one dimensional crystal at a metallic wall and its dependence on the Thomas–Fermi screening length. These calculations provide a simple interpretation for the surface energy in terms of image charges, which allows for an estimation of the interfacial properties in more complex situations of a disordered ionic liquid close to a metal surface. The counter-intuitive outcome is that electronic screening, as characterized by a molecular Thomas–Fermi length lTF, profoundly affects the wetting of ionic systems close to a metal, in line with the recent experimental observation of capillary freezing of ionic liquids in metallic confinement.

scholarly journals Impact of divertor geometry on H-mode confinement in the JET metallic wall

2017 ◽  
Vol 57 (8) ◽  
pp. 086025 ◽  
Author(s):  
E. Joffrin ◽  
P. Tamain ◽  
E. Belonohy ◽  
H. Bufferand ◽  
P. Buratti ◽  
...  
Keyword(s):  
Metallic Wall

Investigation of the Conjugate Convective-Conductive Thermal Behavior of a Rib-Roughened Internal Cooling Channel

2004 ◽  
Author(s):  
Roberto Fedrizzi ◽  
Tony Arts
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Thermal Behavior ◽  
Large Scale ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Heat Flux Distribution ◽  
Metallic Wall ◽  
Scaled Models ◽  
Rib Roughened

The proposed contribution concerns an experimental investigation of the conjugate thermal behavior of a rib-roughened cooling channel. Previous investigations mainly were focused on the convective aspects of the heat transfer; the scaled models were made of low conductivity material and the heat conduction was not representative of the behavior inside a real metallic airfoil. To overcome this limitation, a large-scale facility with a metallic ribbed wall was designed and tested. Infrared thermography was used to measure the temperature distribution on the wetted surface. Dedicated software was developed to correct the temperature field distortions and to apply the radiation-temperature calibration. The convection coefficient was calculated as a function of the measured wall temperature and computed wall heat flux. The code FLUENT® was used to solve the energy equation into the metallic wall, providing the surface heat flux distribution. The complex contribution of the ribs, in terms of heat transfer, was highlighted.

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