A5044997199- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Ion-surface interactions and analysis
- X-ray Spectroscopy and Fluorescence Analysis
- Fullerene Chemistry and Applications
- Diamond and Carbon-based Materials Research
- Astrophysics and Star Formation Studies
- Nuclear physics research studies
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Crystallography and Radiation Phenomena
- Quantum Chromodynamics and Particle Interactions
- Electron and X-Ray Spectroscopy Techniques
- Nuclear Physics and Applications
- Analytical Chemistry and Chromatography
- Photochemistry and Electron Transfer Studies
- Particle Accelerators and Free-Electron Lasers
- Protein Structure and Dynamics
- Polymer Nanocomposite Synthesis and Irradiation
- Porphyrin and Phthalocyanine Chemistry
- Molecular Spectroscopy and Structure
- Laser-Matter Interactions and Applications
- Electrohydrodynamics and Fluid Dynamics
- Laser-Ablation Synthesis of Nanoparticles
- Photoreceptor and optogenetics research
Centre National de la Recherche Scientifique
2010-2022
Sorbonne Université
2001-2022
École Normale Supérieure - PSL
2022
Collège de France
2022
Université Sorbonne Paris Nord
2012-2021
Laboratoire de physique des lasers
2012-2021
Sorbonne Paris Cité
2013-2020
Université Paris Cité
2001-2020
Laboratoire Kastler Brossel
2001-2019
Helmholtz Institute Jena
2019
The interaction of multiply charged ions (He${}^{2+}$, ${\mathrm{O}}^{3+}$, and Xe${}^{20+}$) with gas-phase pericondensed polycyclic aromatic hydrocarbon (PAH) molecules coronene (C${}_{24}$H${}_{12}$) pyrene (C${}_{16}$H${}_{10}$) is studied for low-velocity collisions ($v\ensuremath{\leqslant}0.6$ a.u.). mass spectrometric analysis shows that singly up to quadruply intact are important reaction products. relative experimental yields compared the results a simple classical over-the-barrier...
A large number of studies are devoted to the investigation biomolecular ionization and fragmentation dynamics underlying biological radiation damage. Most these have been based on gas-phase collisions with isolated DNA building blocks. The radiobiological significance is often questioned because lack a chemical environment. To clarify this aspect, we studied interactions keV ions nucleobases nucleobase clusters by means coincidence time-of-flight spectrometry. Significant changes already...
We report the first experimental study of ions interacting with clusters polycyclic aromatic hydrocarbon (PAH) molecules. Collisions between 11.25 keV 3He+ or 360 129Xe20+ and weakly bound one smallest PAH molecules, anthracene, show that C14H10 have much higher tendencies to fragment in ion collisions than other clusters. The ionization is dominated by peripheral which clusters, very surprisingly, are more strongly heated Xe20+ He+ collisions. appearance size k=15 for [C ₁₄H₁₀](k)2+.
The $5g-4f$ transitions in pionic nitrogen and muonic oxygen were measured simultaneously by using a gaseous nitrogen-oxygen mixture at 1.4\,bar. Due to the precise knowledge of muon mass line provides energy calibration for transition. A value (139.57077\,$\pm$\,0.00018)\,MeV/c$^{2}$ ($\pm$\,1.3ppm) is derived negatively charged pion, which 4.2ppm larger than present world average.
Fragmentation of singly charged anions adenosine 5'-monophosphate (AMP-) induced by collisions with neutral atoms (Ne, Na) has been studied at a collision energy 50 keV. The experiments were performed isolated AMP- as well nanosolvated in cluster given number m water molecules. In the first case, dominant fragmentation channels concern loss adenine, PO3- and H2PO4-. latter, molecules becomes dominating process, ion is fully protected when larger than approximately 13. observed fragment...
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...
Abstract In general, radiation‐induced fragmentation of small amino acids is governed by the cleavage CC α bond. We present results obtained with 300 keV Xe 20+ ions that allow molecules (glycine and valine) to be ionised at large distances without appreciable energy transfer. Also in case, bond turns out weakest link hence its scission dominant channel. Intact are observed very low intensities. When embedded a cluster acids, protective effect environment observed. The pattern changes:...
Clusters of fullerenes (C60,C70)(n) are produced in a gas aggregation source and multiply ionized collisions with highly charged Xe(20+,30+) ions. Their stabilities decay processes analyzed high-resolution time-of-flight mass spectrometry. Fullerene clusters charge states up to q=5 have been observed appearance sizes found be as small n(app)=5, 10, 21, 33 for q=2, 3, 4, 5, respectively. The analysis the multicoincident fragmentation spectra indicates high mobility. This is contrast...
We report on an experimental study of the ionization and fragmentation clusters $k$ polycyclic aromatic hydrocarbon (PAH) molecules using anthracene, C${}_{14}$H${}_{10}$, or coronene, C${}_{24}$H${}_{12}$. These PAH are moderately charged strongly heated in small impact parameter collisions with 22.5-keV He${}^{2+}$ ions, after which they mostly decay long monomer evaporation sequences singly comparatively cold monomers as dominating end products. describe a simple cluster model estimate...
C60(2-) and C70(2-) dianions have been produced by electrospray of the monoanions subsequent electron pickup in a Na vapor cell. The were stored an electrostatic ring their decay emission was measured up to 1 s after injection. While ions are stable on this time scale, except for small fraction which excited gas collisions, most millisecond with lifetime depending strongly internal temperature. results can be modeled as tunneling through Coulomb barrier, mainly from thermally populated...
The authors find even-odd variations as functions of r (<or=7) for multiple ionization van der Waals dimers in slow Xe(30+)+[C60]2([C60C70])-->...+[C60]2(r+)([C60C70](r+)) electron-transfer collisions. This behavior is sharp contrast to the smooth one fullerene monomers and may be related effects dimer energies agreement with results from an electrostatic model. kinetic energy releases dissociations [predominantly yielding intact fullerenes [C60]2(r+)-->C60(r1+)+C60(r2+) same (r1=r2) or...
The interaction of keV He+, He2+, and O5+ ions with isolated α β isomers the amino acid alanine was studied by means high resolution coincidence time-of-flight mass spectrometry. We observed a strong isomer dependence characteristic fragmentation channels which manifests in strongly altered branching ratios. Despite ultrashort initial perturbation incoming ion, evidence for molecular rearrangement leading to formation H3+ found. measured kinetic energies ionic fragments can be sufficient...
We have measured the time dependence of fragmentation protonated amino acids and peptides upon UV excitation in an electrostatic ion storage ring. After absorption a 266 nm photon, Trp (TrpH+) has lifetime 10–20 μs but also component with millisecond is present. The long may be due to fluorescence, which leads ions lower energy, or decay Trp+˙ radical cation formed after prompt hydrogen loss laser interaction region. Only one about 10 was detected for TyrH+. photoexcited PheH+ even shorter...
Due to the strong evolution in field of nanotechnologies and continuous miniaturisation electronic components, multiply-charged ion nanobeams would be a promising tool this research. Either for surface modification or local (nanometre scale) analysis purposes, studying feasibility such beams is interest. In present contribution, we focusing technique based on self-organised charge-up simple glass 'funnel'.
We report strong even-odd effects in multiple ionization yields of van der Waals dimers slow ${\mathrm{Xe}}^{30+}+[{\mathrm{C}}_{60}{]}_{2}([{\mathrm{C}}_{60}{\mathrm{C}}_{70}])\ensuremath{\rightarrow}\ensuremath{\cdots}+{[{\mathrm{C}}_{60}{]}_{2}}^{r+}({[{\mathrm{C}}_{60}{\mathrm{C}}_{70}]}^{r+})$ electron-transfer collisions as functions $r\ensuremath{\le}7$. This behavior may be due to variations the sequences dimer energies calculated with an electrostatic model including electrical...
We find that the most stable fullerene isomers, C70–C94, form efficiently in close-to central collisions between keV atomic ions and weakly bound clusters of more than 15 C60-molecules. observe extraordinarily high yields C70 marked preferences for C78 C84. Larger even-size carbon molecules, C96–C180, follow a smooth log-normal (statistical) intensity distribution. Measurements kinetic energies indicate C70–C94 mainly are formed by coalescence reactions small molecules C60, while Cn with...
The experimental investigation of quantum-electrodydamic contributions to the binding energies inner shells highly charged heavy ions requires an accurate spectroscopy in region hard x-rays suitable at a limited source strength. For this purpose focusing compensated asymmetric Laue crystal optics has been developed and twin-spectrometer assembly built commissioned storage ring GSI Helmholtzzentrum Darmstadt. We characterize demonstrate usefulness instrumentation for both stationary fast...
We have measured kinetic energy releases in asymmetric fission, ${\mathrm{C}}_{60}^{r+}\ensuremath{\rightarrow}{\mathrm{C}}_{58}^{(r\ensuremath{-}1)+}+{\mathrm{C}}_{2}^{+}$ $(r=6--9)$ and evaporation ${\mathrm{C}}_{60}^{r+}\ensuremath{\rightarrow}{\mathrm{C}}_{58}^{r+}+{\mathrm{C}}_{2}$ $(r=2,3),$ following multiple-electron removal from ${\mathrm{C}}_{60}$ ${\mathrm{He}}^{2+}$ ${\mathrm{Xe}}^{17+}$ collisions at $3q\mathrm{keV}(q=2,17).$ used the recoil-ion momentum technique limited...
We have studied the outcome of collisions between hydrated nucleotide anion adenosine 5′-monophosphate (AMP) and sodium. Electron capture leads to hydrogen loss as well water evaporation regardless initial number m molecules attached parent ion (m⩽16). The yield dianions with microsecond lifetimes increases strongly m, which is explained from dielectric screening two charges by nanodroplet. For comparison, collision induced dissociation results in losses no or very little damage AMP molecule itself.
We report on measurements of the ionization and fragmentation polycyclic aromatic hydrocarbon (PAH) targets in Xe(20+) + C(16)H(10) [C(16)H(10)](k) collisions compare results for two isomers: pyrene fluoranthene. For both types targets, i.e., single PAH molecules isolated vacuum or isomerically pure clusters one molecules, resulting fragment spectra are surprisingly similar. However, we do observe weak but significant isomer effects. Although these manifested very different ways monomer...
The gas-phase structures of doubly and triply protonated Amyloid-β12-28 peptides have been investigated through the combination ion mobility (IM), electron capture dissociation (ECD) mass spectrometry, infrared multi-photon (IRMPD) spectroscopy together with theoretical modeling. Replica-exchange molecular dynamics simulations were conducted to explore conformational space these peptides, from which several classes found. Among low-lying conformers, those predicted diffusion cross-sections...