Publications associées à Comparison of the DC performance of full- and sub-size NbTi cable-in-conduit conductors

High-frequency response of a hemispherical grounding electrode

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga

The lightning discharge current is characterized by a high-frequency spectrum extending from DC to about 10 MHz. The calculation of the grounding impedance is one of the most important aspects of designing lightning protection systems. The search for analy ...

Elsevier2024

Magnetic structure and magnetoelectric properties of the spin-flop phase in LiFePO4

Sofie Janas, Ellen Fogh, Paola Caterina Forino

We investigate the magnetic structure and magnetoelectric(ME) effect in the high -field phase of the antiferromagnet LiFePO 4 above the critical field of 31 T. A neutron diffraction study in pulsed magnetic fields reveals the propagation vector to be q = 0 ...

Amer Physical Soc2024

Magnetism of Single Surface Adsorbed Atoms Studied with Radio-Frequency STM

Clément Marie Soulard

This thesis investigates the magnetic properties of single atoms and molecules adsorbed on thin magnesium oxide decoupling layers, grown on a silver single crystal. To address these systems experimentally, we use a low temperature scanning tunneling micros ...

EPFL2024

Influence of a lossy ground on the lightning performance of overhead transmission lines

Farhad Rachidi-Haeri, Rafael Silva Alipio

This paper investigates the impact of incorporating both displacement currents and frequency-dependent soil parameters in the calculation of the ground-return impedance for the determination of the backflashover rate of 138 kV and 230 kV overhead transmiss ...

Elsevier2023

Magnetic structure of the two-dimensional XY antiferromagnet Sr2CoSi2O7 studied using single-crystal neutron diffraction

Bálint Náfrádi

We report a combined polarized and unpolarized neutron diffraction study on a multiferroic Sr2CoSi2O7 (SCSO) single crystal below and above the antiferromagnetic ordering temperature TN = 6.5 K. Unpolarized neutron diffraction measurements at 15 K confirm ...

AMER PHYSICAL SOC2023

Single Chip Dynamic Nuclear Polarization Microsystems

Nergiz Sahin Solmaz

Nuclear magnetic resonance (NMR) methods are powerful tools employed in many fields, including physics, chemistry, material science, biology, and medicine. The use of NMR methodologies in an even wider range of applications is often hindered by the relativ ...

EPFL2023

Interaction of lightning-generated electromagnetic fields with overhead and underground cables

Farhad Rachidi-Haeri, Marcos Rubinstein, Carlo Alberto Nucci

In this chapter, we discussed the TL theory and its application to the problem of lightning electromagnetic field coupling to transmission lines. After a short discussion on the underlying assumptions of the TL theory, we described seemingly different but ...

IET2022

The Geometry and Charge of the Streamer Bursts Generated by Lightning Rods under the Influence of High Electric Fields

Farhad Rachidi-Haeri, Marcos Rubinstein

The streamer bursts generated during the initiation and propagation of leaders play an important role in the creation and maintenance of hot discharge channels in air. The most important parameters related to streamer bursts in this respect are the length ...

2022

Order parameters for antiferromagnetic structures: A first-principles study of iridium manganese

Anirudh Raju Natarajan

We use density-functional theory to study the ordered states of iridium manganese, demonstrating a simple but powerful method for describing magnetic structures and the transitions among them. As an illustrative example, the coupling of magnetism and cryst ...

AMER PHYSICAL SOC2022

Canted antiferromagnetic phases in the candidate layered Weyl material EuMnSb2

Xiaoqiang Wang, Xiao Wang

EuMnSb2 is a candidate topological material which can be tuned towards a Weyl semimetal, but there are differing reports for its antiferromagnetic (AFM) phases. The coupling of bands dominated by pure Sb layers hosting topological fermions to Mn and Eu mag ...

AMER PHYSICAL SOC2022

Locomotion of Sensor‐Integrated Soft Robotic Devices Inside Sub‐Millimeter Arteries with Impaired Flow Conditions

Lucio Feo Pancaldi-Giubbini, Lorenzo Francesco John Noseda, Diego Ghezzi, Mahmut Selman Sakar, Adele Fanelli, Amit Yedidia Dolev

One of the grand challenges in interventional cardiology and neuroradiology is to minimize the operation time and risk of damage during catheterization. These two factors drastically increase if the target location resides in small and tortuous vessels. Fl ...

Wiley2022

A geometrically exact model for thin magneto-elastic shells

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla, Dong Yan

We develop a reduced model for hard-magnetic, thin, linear-elastic shells that can be actuated through an external magnetic field, with geometrically exact strain measures. Assuming a reduced kinematics based on the Kirchhoff-Love assumption, we derive a r ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Impact of Frequency-Dependent Soil Models on Grounding System Performance for Direct and Indirect Lightning Strikes

Farhad Rachidi-Haeri

The goal of this article is to investigate the effect of frequency-dependent soil models on the performance of grounding electrodes subjected to lightning strikes. Several soil models are examined while accounting for the variation of soil resistivity and ...

2021

Order and dynamics in Kagome like compound Cu2OSO4 and other quantum magnets

Virgile Yves Favre

This thesis presents results of studies of novel compounds modeling complex fundamental physics phenomena. Cu2OSO4 is a copper based magnetic Mott Insulator system, where spin half magnetic moments form a new type of lattice. These intrinsically quantum pi ...

EPFL2021

Lightning to tall structures: Characterization, Modeling and Protection

Antonio Sunjerga

Lightning physics is highly multidisciplinary, involving areas such as plasma physics, electrical engineering, meteorology, thermodynamics and particle physics. Upward lightning is a special type of lightning initiated from tall structures that has attract ...

EPFL2021

Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic Structure

Gabriel Aeppli, Sara Marti Sanchez, Yu Liu, Vladimir N. Strocov

Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field, and local proximitized magnetic exchange. In this work, we present lattice-matched hybrid epitaxy of semico ...

AMER CHEMICAL SOC2020

Magnetic dynamics across the in-field transition in Ca3Co2O6

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Nagabhushan Ganesh Hegde

The discovery of multiple coexisting magnetic phases in the crystallographically homogeneous compound Ca3Co2O6 has stimulated ongoing research activity. In recent years the main focus has been on the zero-field-state properties, where exceedingly long time ...

AMER PHYSICAL SOC2020

Estimation of performance of Nb3Sn CICC with thermal strain distribution

Rainer Wesche, Pierluigi Bruzzone, Kamil Sedlák

In the last few years, the critical temperature (Tc) of several ITER cable-in-conduit conductors (CICC) was determined by magnetization measurements at zero current. The distribution of the critical temperatures (Tc), caused by variation of strain in the N ...

2020

Isolated vs. Interconnected Wind Turbine Grounding Systems: Effect on the Harmonic Grounding Impedance, Ground Potential Rise and Step Voltage

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga, Qi Li

Wind turbines are very vulnerable to lightning strikes due to their height, sharp edges and remote locations often with high soil resistivity. In this paper we present numerical simulations of the impedance of a typical wind turbine grounding geometry. We ...

Elsevier2019

Tower and Path-Dependent Voltage Effects on the Measurement of Grounding Impedance for Lightning Studies

Marcos Rubinstein, Keyhan Sheshyekani, Hamidreza Karami, Antonio Sunjerga

We present an analysis aimed at evaluating the effect of the presence of the tower on the measurement of the grounding impedance. The Numerical Electromagnetics Code NEC-4 is used for the full-wave modeling of the structure including the tower and its foot ...

2019