Publications associées à Charge Neutralization and Direct Thrust Measurements from Bipolar Pairs of Ionic- Electrospray Thrusters

Antiferromagnetic droplet soliton driven by spin current

We demonstrate that a spin current flowing through a nanocontact into a uniaxial antiferromagnet with first- and second-order anisotropy can excite a self-localized dynamic magnetic soliton, known as a spin-wave droplet in ferromagnets. The droplet nucleat ...

AIP American Institute of Physics2024

Static and Dynamic Voltage Balancing for an IGCT-Based Resonant DC Transformer

Drazen Dujic, Nikolina Djekanovic, Renan Pillon Barcelos

This paper focuses on the operational characteristics of a medium voltage resonant DC transformer based on a split capacitor IGCT 3L-NPC leg. The study delves into both the dynamic and static balancing aspects of the 3L-NPC when operating in a two-level, 5 ...

2024

Direct observations of X-rays produced by upward positive lightning

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga, Thomas Chaumont

X-rays have been observed in natural downward cloud-to-ground lightning for over 20 years and in rocket-triggered lightning for slightly less. In both cases, this energetic radiation has been detected during the stepped and dart leader phases of downward n ...

Nature Publishing Group2024

A 0.21-ps FOM Capacitor-Less Analog LDO with Dual-Range Load Current for Biomedical Applications

Mahsa Shoaran, Yasemin Engür

This paper presents an output capacitor-less low-dropout regulator (LDO) with a bias switching scheme for biomedical applications with dual-range load currents. Power optimization is crucial for systems with multiple activation modes such as neural interfa ...

ArXiv2023

A Prony-based approach for accelerating the lightning electromagnetic fields computation above a perfectly conducting ground

Farhad Rachidi-Haeri, Marcos Rubinstein

Lightning strikes can seriously affect the reliability and availability of electrical infrastructures. The computation of lightning-electromagnetic fields represents one of the most crucial steps in the evaluation of the induced effects; thus, having at di ...

Elsevier2022

Electromechanical investigations and quench experiments on sub-size HTS cables for high field EU-DEMO Central Solenoid

Ortensia Dicuonzo

The aim of this thesis is to investigate the mechanical and thermal behaviour of HTS coated conductor cables for EUROfusion DEMO magnets. One of the issue in large HTS magnets is the safety against a quench. A quench is a sudden thermal runway in which the ...

EPFL2022

Optimization Method for Extracting Stabilizer Geometry and Properties of REBCO Tapes

Bertrand Dutoit, Bertrand Dutoit, Francesco Grilli, Arooj Akbar, Nicolo' Riva

A good knowledge of material properties is a critical aspect for modeling high-temperature superconductor (HTS) devices. However, the electrical resistivity of coated conductors above the critical current is limited. The major challenge in characterizing t ...

2021

Adaptive Body Biasing in Strong Body Factor Technologies

Thomas Christoph Müller

With the advent of intelligent sensor nodes in everyday life, low power aspects of system design become more and more important. Adaptive body biasing is a promising methodology to achieve dynamic adaptation of the tradeoff between performance and energy b ...

EPFL2021

Pushing the Limits of Efficiency and Power Density in High-Frequency Power Conversion Based on Wide-Band-Gap Technologies

Armin Jafari

The emergence of wide-band-gap (WBG) power transistors with low conduction losses and high-speed switching speeds has paved the way for more-than-ever efficient power electronics systems and huge energy saving potentials. Likewise, power density- the ratio ...

EPFL2021

Inflection Phenomenon in Cryogenic MOSFET Behavior

Christian Enz, Farzan Jazaeri, Arnout Lodewijk M Beckers

This brief reports the analytical modeling and measurements of the inflection in the MOSFET transfer characteristics at cryogenic temperatures. Inflection is the inward bending of the drain current versus gate voltage, which reduces the current in weak and ...

2020

Modeling Compact Intracloud Discharge (CID) as a Streamer Burst

Farhad Rachidi-Haeri, Marcos Rubinstein

Narrow Bipolar Pulses are generated by bursts of electrical activity in the cloud and these are referred to as Compact Intracloud Discharges (CID) or Narrow Bipolar Events in the current literature. These discharges usually occur in isolation without much ...

2020

Magnetic electron collimation in three-dimensional semi-metals

Xiangwei Huang, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke, Chunyu Guo

While electrons moving perpendicular to a magnetic field are confined to cyclotron orbits, they can move freely parallel to the field. This simple fact leads to complex current flow in clean, low carrier density semi-metals, such as long-ranged current jet ...

2020

MMC-based conversion for MVDC applications

Stefan Milovanovic

In recent years, DC grids have gained momentum due to the advantages they display over their AC counterparts. For instance, high voltage DC grids have been established as the most prominent solution in the underwater power transmission or interconnection o ...

EPFL2020

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

A programmable low-power ADC interface for an ISFET sweat sensor used in a wearable multi-sensing system

Maher Kayal, François Krummenacher, Evgenia Voulgari

An application specific integrated circuit (ASIC) named ANTIGONE (ANalog To dIGital cONvErter) was designed in AMS 0.35 mu m technology to interface with four Ion-sensitive field-effect transistor (ISFET) sensors and perform real-time monitoring of some bi ...

IEEE2019

2D nanopores: fabrication, energy harvesting and field-effect sensing

Michael Graf

Solid-state nanopores are man-made, nano-sized openings in membranes separating two chambers containing an electrolyte solution. When applying an electric field across the membrane, the nanopore provides the only path for mobile ions to pass from one side ...

EPFL2019

Advanced linear models for gyro-backward wave instabilities in gyrotrons

Jérémy Genoud

Parasitic oscillations excitation is one of the main point hindering high-power gyrotron operation for fusion application. These instabilities, besides being dangerous for the gyrotron components, could possibly degrade the electron beam quality before it ...

EPFL2019

Electromagnetic Fields Associated With the M‐Component Mode of Charge Transfer

Marcos Rubinstein, Davide Pavanello, Mohammad Azadifar, Lixia He

In upward flashes, charge transfer to ground largely takes place during the initial continuous current (ICC) and its superimposed pulses (ICC pulses). ICC pulses can be associated with either M-component or leader/return-stroke like modes of charge transfe ...

2019

A Study of a Large Bipolar Lightning Event Observed at the Säntis Tower

Farhad Rachidi-Haeri, Marcos Rubinstein, Davide Pavanello, Mohammad Azadifar, Wolfgang Schulz

An unusual negative lightning flash was recorded at the Säntis Tower on June 15, 2012. The flash did not contain an initial continuous current typical of upward negative lightning, which is the most common type of event at the Säntis Tower. The flash conta ...

2019

On-Chip High-Voltage Sensors Based on Trap-Assisted 2DEG Channel Control

Elison de Nazareth Matioli, Armin Jafari

In this work, we present a new device concept for compact high-voltage sensing with high-impedance input port, consisting of an AlGaN/GaN high-electron-mobility channel controlled by trapped carriers generated by a metallic electrode. The high-voltage appl ...

Institute of Electrical and Electronics Engineers2019