Publications associées à New architecture for the analog front-end of Medipix4

High-rate, high-resolution single photon X-ray imaging: Medipix4, a large 4-side buttable pixel readout chip with high granularity and spectroscopic capabilities

Jean-Michel Sallese, Adil Koukab, Viros Sriskaran

The Medipix4 chip is the latest member in the Medipix/Timepix family of hybrid pixel detector chips aimed at high -rate spectroscopic X-ray imaging using high -Z materials. It can be tiled on all 4 sides making it ideal for constructing large -area detecto ...

Iop Publishing Ltd2024

Element- and enantiomer-selective visualization of molecular motion in real-time

Majed Chergui, Malte Oppermann, Jérémy Raymond Jean Maurice Rouxel

Ultrafast optical-domain spectroscopies allow to monitor in real time the motion of nuclei in molecules. Achieving element-selectivity had to await the advent of time resolved X-ray spectroscopy, which is now commonly carried at X-ray free electron lasers. ...

Nature Portfolio2023

Medipix4, a high granularity four sides buttable pixel readout chip for high resolution spectroscopic X-ray imaging at rates compatible with medical CT scans

Viros Sriskaran

Medipix4 is the latest member in the Medipix/Timepix family of pixel detector chips aimed at high rate spectroscopic X-ray imaging using high-Z materials. The chip address the limitations of conventional hybrid pixel detectors for X-ray imaging. Its predec ...

EPFL2022

Self-consistent Hubbard parameters from density-functional perturbation theory in the ultrasoft and projector-augmented wave formulations

Nicola Marzari, Matteo Cococcioni, Iurii Timrov

The self-consistent evaluation of Hubbard parameters using linear-response theory is crucial for quantitatively predictive calculations based on Hubbard-corrected density-functional theory. Here, we extend a recently introduced approach based on density-fu ...

AMER PHYSICAL SOC2021

Ultrafast X-ray Spectroscopy of Heme Proteins

Dominik Kinschel

With the advent of X-ray free-electron lasers (XFELs) time-resolved X-ray spectroscopic techniques have advanced to the femtosecond regime. These are element selective techniques which offer unique insight into the electronic and chemical environment and d ...

EPFL2020

Attosecond transient absorption spooktroscopy: a ghost imaging approach to ultrafast absorption spectroscopy

Andre Al Haddad, Christoph Bostedt, Jonas Knurr, Siqi Li, Zhaoheng Guo

The recent demonstration of isolated attosecond pulses from an X-ray free-electron laser (XFEL) opens the possibility for probing ultrafast electron dynamics at X-ray wavelengths. An established experimental method for probing ultrafast dynamics is X-ray t ...

ROYAL SOC CHEMISTRY2020

Toward time-resolved laser T-jump/X-ray probe spectroscopy in aqueous solutions

Majed Chergui, Giulia Fulvia Mancini, Dominik Kinschel, Benjamin Bauer, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle

Most chemical and biochemical reactions in nature and in industrial processes are driven by thermal effects that bring the reactants above the energy barrier for reaction. In aqueous solutions, this process can also be triggered by the laser driven tempera ...

2019

Towards X-ray transient grating spectroscopy

Majed Chergui, Paul Beaud, Christian David, Giulia Fulvia Mancini, Erwan Fabrice Koch, Jérémy Raymond Jean Maurice Rouxel

The extension of transient grating spectroscopy to the x-ray regime will create numerous opportunities, ranging from the study of thermal transport in the ballistic regime to charge, spin, and energy transfer processes with atomic spatial and femtosecond t ...

OPTICAL SOC AMER2019

Diagnostic of fast-ion energy spectra and densities in magnetized plasmas

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Yves Martin, Richard Pitts, Olivier Sauter, Henri Weisen, Stefano Coda, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Duccio Testa, Mikhail Maslov, Javier García Hernández, David Pfefferlé, Dalziel Joseph Wilson, Jonathan Marc Philippe Faustin, Federico Nespoli, Hamish William Patten, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Liang Yao, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Bernhard Sieglin

The measurement of the energy spectra and densities of alpha-particles and other fast ions are part of the ITER measurement requirements, highlighting the importance of energy-resolved energetic-particle measurements for the mission of ITER. However, it ha ...

IOP PUBLISHING LTD2019

Charge-carrier Dynamics in Metal Oxides and Hybrid Lead Perovskites investigated by Time-Resolved UV and X-ray Spectroscopy

Thomas Charles Henry Rossi

In modern ultrafast optoelectronic technologies based on wide band gap insulators, the non-equilibrium dynamics of photogenerated charges plays a major role. Unravelling the mechanisms of interaction between these charge carriers and their environment is c ...

EPFL2018

Low Temperature Wet Conformal Nickel Silicide Deposition for Transistor Technology through an Organometallic Approach

Giovanni De Micheli, Michele De Marchi, Pierre-Emmanuel Julien Marc Gaillardon, Tsung-Han Lin, Maxime Victor Thammasack, David Baudouin

The race for performance of integrated circuits is nowadays facing a downscale limitation. To overpass this nanoscale limit, modern transistors with complex geometries have flourished, allowing higher performance and energy efficiency. Accompanying this br ...

Amer Chemical Soc2017

Excited state X-ray absorption spectroscopy: Probing both electronic and structural dynamics

Majed Chergui, Simon Neville

We investigate the sensitivity of X-ray absorption spectra, simulated using a general method, to properties of molecular excited states. Recently, Averbukh and co-workers [M. Ruberti et al., J. Chem. Phys. 140, 184107 (2014)] introduced an efficient and ac ...

American Institute of Physics2016

Water-Mediated Ion Pairing: Occurrence and Relevance

Sylvie Roke

We present an overview of the studies of ion pairing in aqueous media of the past decade. In these studies, interactions between ions, and between ions and water, are investigated with relatively novel approaches, including dielectric relaxation spectrosco ...

American Chemical Society2016

Saturation of the response to stochastic forcing in two-dimensional backward-facing step flow: A self-consistent approximation

François Gallaire, Vladislav Mantic Lugo

Selective noise amplifiers are characterized by large linear amplification to external perturbations in a particular frequency range despite their global linear stability. Applying a stochastic forcing with increasing amplitude, the response undergoes a st ...

Amer Physical Soc2016

Identifying the major intermediate species by combining time-resolved X-ray solution scattering and X-ray absorption spectroscopy

Thomas James Penfold

Identifying the intermediate species along a reaction pathway is a first step towards a complete understanding of the reaction mechanism, but often this task is not trivial. There has been a strong on-going debate: which of the three intermediates, the CHI ...

Royal Soc Chemistry2015

Polarizable embedding with a multiconfiguration short-range density functional theory linear response method

We present here the coupling of a polarizable embedding (PE) model to the recently developed multiconfiguration short-range density functional theory method (MC-srDFT), which can treat multiconfigurational systems with a simultaneous account for dynamical ...

Amer Inst Physics2015

Effect of surface pretreatment of TiO2 films on interfacial processes leading to bacterial inactivation in the dark and under light irradiation

Michaël Bensimon, Juan Kiwi, César Pulgarin, Rosendo Sanjines, Sami Rtimi, Jelena Nesic

Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escher ...

Royal Society, The2014

Sub-femtosecond precision measurement of relative X-ray arrival time for free-electron lasers

Christoph Peter Hauri, Christoph Bostedt

Today's brightest coherent X-ray sources, X-ray free-electron lasers, produce ultrafast X-ray pulses for which full-width at half-maximum durations as short as 3 fs have been measured(1). There has been a marked increase in the popularity of such short pul ...

Nature Publishing Group2014

Hydrophobicity with atomic resolution: Steady-state and ultrafast X-ray absorption and molecular dynamics studies

Majed Chergui, Ivano Tavernelli, Thomas James Penfold

Static and time-resolved X-ray absorption spectroscopy (XAS) is used to probe the solvent shell structure around iodide and iodine. In particular, we characterize the changes ob served upon electron abstraction of aqueous iodide, which reflects the transit ...

De Gruyter2013

4,4' Functionalized 2,2'-Bipyridines : Synthesis and Applications as Catalytically Active Nanoparticle Stabilizers and Ligands for Ruthenium Dye Molecules

Ryan Dykeman

This thesis presents two applications of 2,2'-bipyridine (bipy) derivatives, the first involves their use as stabilizers for nanoparticle (NP) catalysts and the second is concerned with the use of bipy ligands for ruthenium dye molecules applied in dye sen ...

EPFL2011