A5080541293- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Therapy and Dosimetry
- Electron and X-Ray Spectroscopy Techniques
- Spectroscopy and Quantum Chemical Studies
- Cold Atom Physics and Bose-Einstein Condensates
- Diamond and Carbon-based Materials Research
- Nuclear Physics and Applications
- Advanced Materials Characterization Techniques
- Quantum, superfluid, helium dynamics
- Laser-induced spectroscopy and plasma
- Advanced Radiotherapy Techniques
- Metallic Glasses and Amorphous Alloys
- Radiation Effects in Electronics
- Magnetic properties of thin films
- Radiation Shielding Materials Analysis
- Quantum optics and atomic interactions
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Theoretical and Computational Physics
- Magnetic Properties of Alloys
- Rare-earth and actinide compounds
Centre de Recherche sur les Ions, les Matériaux et la Photonique
2015-2025
Université de Caen Normandie
2007-2024
École Nationale Supérieure d'Ingénieurs de Caen
2013-2024
Centre National de la Recherche Scientifique
2013-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2012-2022
Normandie Université
2017-2022
Maison de la Simulation
2005-2021
Institut des NanoSciences de Paris
2015
GANIL
1998-2007
Université Paris Cité
2003
We investigate the dynamics of dicationic metal-oxide molecules under large electric-field conditions, on basis ab initio calculations coupled to molecular dynamics. Applied case ${\mathrm{ZnO}}^{2+}$ in field atom probe tomography (APT), our simulation reveals dissociation into three distinct exit channels. The proportions these channels depend critically strength and initial orientation with respect field. For typical used APT experiments, an efficient channel leads emission neutral oxygen...
We present the deformation pathway of critically charged glycol and water droplets from onset Rayleigh instability compare it to numerical results, obtained for perfectly conducting inviscid droplets. In this simple model presented here, time evolution droplet shape is given by velocity potential equation. The Laplace equation solved expanding onto harmonic functions. For part dominated electrostatic pressure, calculations reproduce experimental data nicely, both, microdroplets. find that in...
We measured kinetic energies of the fragment ions argon dimers multiply ionized by low-energy Ar(9+) collisions. For (Ar2)(4+) dissociation, asymmetric channel (Ar(3+) + Ar(+)) yield is found unexpectedly higher than symmetric (Ar(2+) Ar(2+)) in contrast with previous observation for covalent molecules or clusters. dissociation (Ar2)(2+)→Ar(+) Ar(+), two well-separated peaks were observed, clearly evidencing that direct Coulombic and radiative charge transfer followed ionic alternatively...
We have studied the fragmentation of water vapour molecules induced by collision with a beam at 6.7 MeV/u. From measurement fragment time flight, we show that amount due to multiple ionization is very large. In case single ionization, are able reproduce accurately experimental cross sections calculating for each molecular level single-ionization section in framework CDW-EIS theory and diagram dissociation modified respect obtained dipolar ionization. By using qualitative arguments based on...
We provide the experimental evidence that single electron capture process in slow collisions between ${\mathrm{O}}^{3+}$ ions and neon dimer targets leads to an unexpected production of low-energy electrons. This results from interatomic Coulombic decay process, subsequent inner-shell one site dimer. Although pure one-electron inner shell is expected be negligible low collision energy regime investigated here, due this overtakes by 1 order magnitude emission Auger electrons scattered...
The measurement of the triple differential cross section in body frame for double photoionization a molecule can be made principle by detecting ionic fragments and two photoelectrons coincidence---but only if dynamics geometry dissociation doubly charged molecular ion are known. A classical trajectory study nine lowest states water dication is presented using high quality ab initio potential-energy surfaces. Sampling from semiclassical initial distribution positions momenta used to...
Using a multi-scale theoretical approach from first principles, we show that the production of HO2 radicals in liquid water can be understood initial Coulomb explosion doubly ionized molecules. Based on separation time scales, used three different models, each one associated with specific scale. The ∼1 fs radiolysis is taken care Monte Carlo code whose basic ingredients are cross-sections. These have been calculated present work using continuum distorted wave eikonal state (CDW-EIS) model...
Pure carbon clusters have received considerable attention for a long time. However, fundamental questions such as what the smallest stable cluster dication is remain unclear. Here, we investigated stability and fragmentation behavior of C_n^{2+} (n=2-4) dications using state-of-the-art atom probe tomography. These small doubly charged ions were produced by laser-pulsed field evaporation from tungsten carbide emitter. Correlation analysis fragments detected in coincidence reveals that they...
We have measured electron yields from the beam entrance and exit surfaces of thin carbon foils (d\ensuremath{\approxeq}4--700 \ensuremath{\mu}g/${\mathrm{cm}}^{2}$) bombarded with swift (13.6 MeV/u) highly charged (q=16--18) argon ions. The dependence on target thickness charge state ions is analyzed within framework an extended semiempirical model. Due to high velocity ions, it possible distinguish production in primary ionization (related stopping power effective ions) secondary due...
We present a theoretical model to study the dynamics of metallic clusters embedded in rare gas matrix. describe active electrons cluster using time dependent density functional theory, while surrounding matrix is described terms classical molecular polarizable atoms. The coupling between and atoms deduced from work Groß Spiegelmann [J. Chem. Phys. 108, 4148 (1998)] reformulated explicitly simple efficient form. electron interaction takes form an averaged dipole fluctuation term, which...
We investigate the radiolysis of liquid water confined in a porous silica matrix by means an event-by-event Monte Carlo simulation electron penetration this composite system. focus on physical and physicochemical effects that take place picosecond range, before radicals start to diffuse react. determine radiolytic yields primary species for system made cylindrical pores filled with over wide range pore radii RC. show relative position conduction band edge V0 both materials plays major role...
We present a theoretical investigation of visible absorption and related luminescence alkali atoms (Li, Na, K) embedded in Ar matrix. used model based on core polarization pseudopotentials, which allows us to determine accurately the gas-to-matrix shifts various trapping sites. The remarkable agreement between our calculated results experimental spectra recorded by several authors establish clear assignment observed spectra, are made contributions from crystalline sites one hand, grain...
The molecular electronic states of the SiO2+ dication have been investigated in a joint theoretical and experimental analysis. use tip-shaped sample for tomographic atom probe analysis offers unique opportunity to produce analyze lifetime some excited this dication. perturbation brought by large electric field polarized tip along ion trajectory is analyzed means dynamics simulation. For typical fields used experiment, lowest energy triplet spontaneously dissociate, while singlet do not. We...
We investigated the transport of heavy-ion-induced electrons in solids by both experiment and numerical simulation. measured electron yields from beam entrance exit surfaces thin carbon foils (d\ensuremath{\approxeq}3 \ensuremath{\mu}g/${\mathrm{cm}}^{2}$--50 mg/${\mathrm{cm}}^{2}$) bombarded with swift, highly charged ${\mathrm{Cu}}^{\mathit{q}+}$ (q=25--28 ${\mathit{E}}_{\mathit{P}}$=9.6 MeV/u) ${\mathrm{Ni}}^{\mathit{q}+}$ (q=26, 28 ${\mathit{E}}_{\mathit{P}}$=74 ions. obtained lengths...
We investigate fast, highly charged ion-induced HOD molecule fragmentation dynamics. Focusing on double ionization of the molecule, we evidence a strong preferential cleavage O–H bond rather than O–D bond. find an isotopic branching ratio defined as number H+ + OD+ over D+ OH+ dissociations 6.5 ± 0.5. Moreover, coincident measurement, by imaging techniques, high-resolution kinetic energy release (KER) distributions for different channels shows, first time, clear difference approximately 1 eV...
We study the dissociative ionization of water clusters by impact 12 MeV/u Ni25+ ions. Cold target recoil ion momentum spectroscopy (COLTRIMS) is used to obtain information about stability, energetics and charge mobility ionized clusters. An unusual stability H9O+4 observed, which could be signature so-called Eigen structure in gas-phase From analysis coincidences between charged fragments, we conclude that very high responsible for formation protonated clusters, (H2O)nH+, dominate mass...