Publications associées à Hélium 4

Validation of 2D T e and n e measurements made with Helium imaging spectroscopy in the volume of the TCV divertor

Basil Duval, Patrick Blanchard, Holger Reimerdes, Christian Gabriel Theiler, Artur Perek, Dmytry Mykytchuk, Cedric Kar-Wai Tsui, Hugo De Oliveira, Filippo Bagnato, Lorenzo Martinelli, Sophie Danielle Angelica Gorno, Claudia Colandrea, Nicola Offeddu

Multi-spectral imaging of helium atomic emission (HeMSI) has been used to create 2D poloidal maps of T-e and ne in TCV's divertor. To achieve these measurements, TCV's MANTIS multispectral cameras (Perek et al 2019 Rev. Sci. Instrum. 90 123514) simultaneou ...

IOP Publishing Ltd2023

Engineering SYK Interactions in Disordered Graphene Flakes under Realistic Experimental Conditions

Oleg Yazyev, Marta Agnieszka Brzezinska, Yifei Guan

We model interactions following the Sachdev-Ye-Kitaev (SYK) framework in disordered graphene flakes up to 300 000 atoms in size (-100 nm in diameter) subjected to an out-of-plane magnetic field B of 5-20 Tesla within the tight-binding formalism. We investi ...

AMER PHYSICAL SOC2023

Progress in the design and manufacturing of the EDIPO 2 cryostat

Pierluigi Bruzzone, Kamil Sedlák, Roberto Guarino, Evgeny Solodko

A major upgrade of the European DIPOle (EDIPO) test facility, which will allow the testing of superconducting samples both for fusion and for high-energy physics applications, is taking place at the Swiss Plasma Center. With a target background field of 15 ...

2023

In situ work function measurements of W, WO3 nanostructured surfaces

Francisco Sanchez

Surface nanostructuring enables the fabrication of materials with highly desirable properties. Nanostructured tungsten surfaces have potential applications in solar water splitting. Exposing a polished tungsten surface to helium plasma induces various surf ...

ELSEVIER SCIENCE SA2022

Nuclei with Up to A=6 Nucleons with Artificial Neural Network Wave Functions

Giuseppe Carleo

The ground-breaking works of Weinberg have opened the way to calculations of atomic nuclei that are based on systematically improvable Hamiltonians. Solving the associated many-body Schrodinger equation involves non-trivial difficulties, due to the non-per ...

SPRINGER WIEN2022

Preliminary design of the pressure relief system of the EDIPO 2 helium vessel

Pierluigi Bruzzone, Kamil Sedlák, Roberto Guarino, Evgeny Solodko

The European Dipole (EDIPO) test facility is undergoing a major upgrade of its magnet assembly, which will provide ground for testing both fusion and high-energy physics superconducting samples at variable temperature and with a background field of 15 T. I ...

2022

How to improve the efficiency of a traditional dissolution dynamic nuclear polarization (dDNP) apparatus: Design and performance of a fluid path compatible dDNP/LOD-ESR probe

Andrea Capozzi, Jean-Noël Hyacinthe, Thanh Phong Kevin Lê

Dissolution Dynamic Nuclear Polarization (dDNP) was invented almost twenty years ago. Ever since, hardware advancement has observed 2 trends: the quest for DNP at higher field and, more recently, the development of cryogen free polarizers. Despite the DNP ...

Academic Press Inc - Elsevier Science2022

Directional detection of light dark matter from three-phonon events in superfluid He-4

Angelo Esposito

We present the analysis of a new signature for light dark matter detection with superfluid He-4: the emission of three phonons. We show that, in a region of mass below the MeV, the kinematics of this process can offer a way to reconstruct the dark matter i ...

American Physical Society2021

Progress on the Design of the 15 T Magnet of the EDIPO Test Facility

Pierluigi Bruzzone, Kamil Sedlák, Roberto Guarino, Evgeny Solodko

EDIPO 2 (the upgraded EDIPO test facility) will provide a unique testbed for superconducting cables for fusion magnets,accelerators, and other applications. Compared to the previous magnet assembly, the magnetic field is enhanced from 12.35 T to 15 T, the ...

IEEE Institute of Electrical and Electronics Engineers2021

Dark matter, dark photon and superfluid He-4 from effective field theory

Angelo Esposito, Emma Michèle Ginette Geoffray

We consider a model of sub-GeV dark matter whose interaction with the Standard Model is mediated by a new vector boson (the dark photon) which couples kinetically to the photon. We describe the possibility of constraining such a model using a superfluid He ...

2020

Light Dark Matter and Superfluid He-4 from EFT

Angelo Esposito

We study the response of a He-4 detector to the interaction of sub-GeV dark matter using an effective field theory for the superfluid. We compute the lifetime of the phonon, which agrees with what known from standard techniques, hence providing an importan ...

IOP PUBLISHING LTD2020

Bosonic superfluid transport in a quantum point contact

Jean-Philippe Brantut

We present a microscopic theory of heat and particle transport of an interacting, low-temperature Bose- Einstein condensate in a quantum point contact.We show that, in contrast to charged, fermionic superconductors, bosonic systems feature tunneling proces ...

2020

Sub-GeV dark matter in superfluid He-4: an effective theory approach

Angelo Esposito

We employ an effective field theory to study the detectability of sub-GeV dark matter through its interaction with the gapless excitations of superfluid 4He. In a quantum field theory language, the possible interactions between the dark matter and the supe ...

Springer2019

Maximizing specific energy by breeding deuterium

Justin Richard Ball

Specific energy (i.e. energy per unit mass) is one of the most fundamental and consequential properties of a fuel source. In this work, a systematic study of measured fusion cross-sections is performed to determine which reactions are potentially feasible ...

IOP Publishing Ltd2019

Sub-MeV dark matter and the Goldstone modes of superfluid helium

Angelo Esposito

We show how a relativistic effective field theory for the superfluid phase of 4 He can replace the standard methods used to compute the production rates of low-momentum excitations due to the interaction with an external probe. This is done by studying the ...

American Physical Society2019

Helium-induced electronic transitions in photo-excited Ba+–Hen exciplexes

Marcel Drabbels

The possibility for helium-induced electronic transitions in a photo-excited atom is investigated using Ba+ excited to the 6p 2P state as a prototypical example. A diabatization scheme has been designed to obtain the necessary potential energy surfaces and ...

2018

Measurement of Antiproton Production in p-He Collisions at root S-NN=110 GeV

Olivier Schneider, Aurelio Bay, Guido Haefeli, Christoph Frei, Tatsuya Nakada, Frédéric Blanc, Michel De Cian, Luca Pescatore, François Fleuret, Chitsanu Khurewathanakul, Alessio Ferrari, Basile Schäli, Elena Graverini, Matthieu Philippe Luther Marinangeli, Renato Quagliani, Jessica Prisciandaro, Federico Betti, Mark Tobin, Greig Alan Cowan, Aravindhan Venkateswaran, Vladislav Balagura, Luis Miguel Garcia Martin, Pietro Marino, Vitalii Lisovskyi, Mirco Dorigo, Jian Wang, Mingkui Wang, Sebastiana Gianì, Zhirui Xu, Federico Leo Redi, Maxime Schubiger, Yi Zhang, Guido Andreassi, Lei Zhang, Violaine Bellée, Preema Rennee Pais, Pavol Stefko, Minh Tâm Tran, Tara Nanut, Niko Neufeld, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Investigations and numerical modeling of mechanical properties of tempered martensitic steel Eurofer97 at various loading rates, temperatures and after spallation irradiation

Serafin Knitel

The reduced activation tempered martensitic steel Eurofer97 is a reference steel for a structural applica-tions in fusion reactors. The first-wall and blanket materials will be subjected to high thermal and neutron fluxes and will experience very complex, ...

EPFL2018

Dependence of the L-Mode scrape-off layer power fall-off length on the upper triangularity in TCV

Stefano Coda, Holger Reimerdes, Benoît Labit, Christian Gabriel Theiler, Antoine Pierre Emmanuel Alexis Merle, Roberto Maurizio, Bernhard Sieglin

This paper reports on experimental observations on TCV with a scan in upper triangularity

{\delta }_{\mathrm{up}}

, including negative triangularity, focusing on the power fall-off length

{\lambda }_{{\rm{q}}}

in L-Mode. The upper triangularity is scann ...

2018

Properties of helium bubbles in covalent systems at the nanoscale: A combined numerical and experimental study

Cécile Hébert, Duncan Thomas Lindsay Alexander

The properties of nanometric-sized helium bubbles in silicon have been investigated using both spatially resolved electron-energy-loss spectroscopy combined with a recently developed method, and molecular-dynamics simulations. The experiments allowed for a ...

Amer Physical Soc2017