Concept

Vide (physique)

Publications associées (28)

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation

In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to ...

2024

Switching the on-surface orientation of oxygen-functionalized helicene

Christian Wäckerlin

Helicenes represent an important class of chiral organic material with promising optoelectronic properties. Hence, functionalization of surfaces with helicenes is a key step toward new organic materials devices. The deposition of a heterohelicene containin ...

Wiley2024

Equilibrium pressure limits in stellarators

Antoine Baillod

This thesis delves into the potential of magnetic fusion energy, and in particular focuses on the stellarator concept. Stellarators use external coils to produce 3-dimensional (3D) magnetic fields that confine a thermonuclear plasma in a topologically toro ...

EPFL2023

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part I—Analysis Based on Time Domain Electromagnetic Radiation

Farhad Rachidi-Haeri, Marcos Rubinstein

In this paper, an inequality satisfied by the vacuum energy density of the universe is derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant ...

2023

Selectively Exciting and Probing Radiative Plasmon Modes on Short Gold Nanorods by Scanning Tunneling Microscope-Induced Light Emission

Olivier Martin

We study the plasmon modes of gold nanorods (as short as similar to 100 nm) on a nonmetallic conductive substrate using scanning tunneling microscope-induced light emission (STM-LE) with a nonplasmonic tungsten tip at room temperature in high vacuum (10-7 ...

AMER CHEMICAL SOC2023

Investigations on Caesium Dispersion and Molybdenum Coating on SPIDER Components

Basile Marie Jacques Pouradier Duteil

SPIDER is the 100 keV full-size Negative Ion Source prototype of the ITER Neutral Beam Injector, operating at Consorzio RFX in Padova, Italy. The largest Negative Ion Source in the world, SPIDER generates an RF driven plasma from which Deuterium or Hydroge ...

2023

Full Solution Process of a Near-Infrared Light-Emitting Electrochemical Cell Based on Novel Emissive Ruthenium Complexes of 1,10-Phenanthroline-Derived Ligands and a Eutectic Alloy as the Top Electrode

Mohammad Khaja Nazeeruddin

Near-infrared luminescent materials have recently received considerable attention for a large number of applications, including in solid-state lighting, as bioimaging agents, as photovoltaic cells, and in the telecommunication industry. By adding diverse e ...

AMER CHEMICAL SOC2023

Ultralow secondary electron emission and improved vacuum surface insulation of polyimide with scalable nanocomposite coating

Chao Wang, Guang-Yu Sun

Polymers with high surface electric insulation capability are greatly demanded in various electrical devices operating in vacuum ambient. Low secondary electron emission (SEE) is favorable to mitigate vacuum flashover by inhibiting the SEE avalanche across ...

ELSEVIER2022

Simulating energetic particle losses in JET plasmas with a reverse integration biasing scheme

Mario Ludovico Podesta, Matteo Vallar

An integrated energetic particle transport model has been constructed in JET plasmas constrained by experimental fast ion loss measurements. The model incorporates a synthetic fast ion loss detector identical to JET's thin-foil Faraday cup fast ion loss de ...

IOP Publishing Ltd2022

General invariance and equilibrium conditions for lattice dynamics in 1D, 2D, and 3D materials

Nicola Marzari, Samuel Poncé, Changpeng Lin

The long-wavelength behavior of vibrational modes plays a central role in carrier transport, phonon-assisted optical properties, superconductivity, and thermomechanical and thermoelectric properties of materials. Here, we present general invariance and equ ...

NATURE PORTFOLIO2022

Synthesis of near-diffraction-free orbital-angular-momentum space-time wave packets having a controllable group velocity using a frequency comb

Tobias Kippenberg, Maxim Karpov, Zhe Zhao

Novel forms of light beams carrying orbital angular momentum (OAM) have recently gained interest, especially due to some of their intriguing propagation features. Here, we experimentally demonstrate the generation of near-diffraction-free two-dimensional ( ...

Optica Publishing Group2022

Semiclassical methods in conformal field theories scrutinized by the epsilon-expansion

Gil Badel

Conformal Field Theories (CFTs) are crucial for our understanding of Quantum Field Theory (QFT). Because of their powerful symmetry properties, they play the role of signposts in the space of QFTs. Any method that gives us information about their structure ...

EPFL2022

Global fluid simulation of plasma turbulence in a stellarator with an island divertor

Paolo Ricci, Joaquim Loizu Cisquella, Maurizio Giacomin, António João Caeiro Heitor Coelho

Results of a three-dimensional, flux-driven, electrostatic, global, two-fluid turbulence simulation for a five-field period stellarator with an island divertor are presented. The numerical simulation is carried out with the GBS code, recently extended to s ...

IOP Publishing Ltd2022

Dielectric properties of 3-3 flexible composites by infiltration of elastomers into porous ceramic structures using cellulose scaffold

Frank Nüesch, Thomas Geiger

Elastomer composites are prepared by infiltrating polydimethylsiloxane (PDMS) into a porous ceramic structure of nanoparticles. This method differs from the conventional approach, where particles are dispersed into the polymer matrix, since here, the polym ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Performance of a high vacuum, high temperature compatible millimeter-range viewing dump for the vertical ECE experiment on TCV

Ambrogio Fasoli, Laurie Porte, Arsène Stéphane Tema Biwole

A high vacuum and high temperature compatible viewing dump, made of MACOR, was designed and installed in TCV for Vertical ECE experiments in the 75-110 GHz frequency range. Measurements of the dump prior to installation in the tokamak showed in more than 9 ...

2021

Techno-economic assessment of postcombustion carbon capture using high-performance nanoporous single-layer graphene membranes

Kumar Varoon Agrawal, Mostapha Dakhchoune, Marina Micari

High-performance membranes have emerged as an energy-efficient alternative to absorption-based postcombustion carbon capture. So far, the techno-economic analyses have been centered around the polymeric membranes. Recently, nanoporous single-layer graphene ...

2021

Beam induced vacuum effects in the future circular hadron collider beam vacuum chamber

Lotta Maria Mether

EuroCirCol is a conceptual design study of a post-LHC, Future Circular Hadron Collider (FCC-hh) with 50 TeV of beam energy and 100 km long, which aims to expand the current energy and luminosity frontiers. The vacuum chamber of the FCC-hh will have to cope ...

2020

Suspended micro/nano channel resonators: a review

Luis Guillermo Villanueva Torrijo, Annalisa De Pastina

Micro- and nano-electromechanical systems (M/NEMS) have demonstrated outstanding sensing capabilities down to the yoctogram (10(-24) g) scale in vacuum environment and cryogenic temperatures. In order to bring such extraordinary resolution levels into the ...

2020

Electron flux and pressure dynamic in the LHC vacuum pilot sector as a function of beam parameters and beam pipe properties

Ambrogio Fasoli, Elena Buratin

The Large Hadron Collider (LHC) is affected by the electron cloud (EC) phenomenon that can provoke beam instabilities, detrimental heat loads and pressure increases in the vacuum system. An innovative dedicated system called vacuum pilot sector (VPS) provi ...

2020

Spontaneous conformal symmetry breaking in fishnet CFT

Mikhail Chapochnikov, Georgios Karananas

Quantum field theories with exact but spontaneously broken conformal invariance have an intriguing feature: their vacuum energy (cosmological constant) is equal to zero. Up to now, the only known ultraviolet complete theories where conformal symmetry can b ...

2020