Publications de Marcel Drabbels

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Transmission electron microscopy at atomic-resolution is a crucial tool in a variety of fields, ranging from materials science to biology. [1,2] Fast electron cameras have recently enabled high-speed observations atomic resolution. [3] Moreover, they have ...

The dynamics of proteins that are associated with their function typically occur on the microsecond timescale, orders of magnitude faster than the time resolution of cryo-electron microscopy. We have recently introduced a novel approach to time-resolved cr ...

The rapid growth of the field of time-resolved and ultrafast electron microscopy has been accompanied by the active development of new instrumentation. Recently, time-resolved microscopes equipped with a field emission gun have been introduced, demonstrati ...

The sign of the theoretically predicted steric asymmetry S in rotational inelastic state resolved molecule–atom collisions is questioned. It is shown that the sign of the T-matrix obtained on a basis of non-oriented rotational states of the molecule depends on the choice of the Jacobi coordinates in which the collision problem is solved. Explicit expressions for the state-to-state dependence of the integral and differential cross-sections for oriented and non-oriented molecules are presented. The effect of

Transitions from bound atomic Rydberg Stark states in a static electric field to autoionizing Rydberg states above the electric-field-induced ionization threshold are studied using a broadband, tunable free-electron laser (photon energy 160-1400 cm(-1), pulse duration similar to 1 ps) and compared with multichannel quantum defect theory calculations. An atomic streak camera is used to record the time-resolved electron emission transients of the autoionizing atoms. For Stark states located on the downfield s

The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property ...

Ultra-high-resolution spectroscopic studies have been performed to elucidate the conformational landscape of the succinamide-based thread 1 that is frequently employed in mechanically interlocked molecular assemblies. We show how dissolving single molecule ...

The translational dynamics of CF3 in liquid helium have been investigated by photodissociating CF3I dissolved in helium droplets consisting of several thousands of atoms. The velocity distribution of CF3 fragments that have escaped from the droplets has been determined using ion imaging techniques and is found to be considerably shifted to lower speeds with respect to the photodissociation of gas phase CF3I. The fragments furthermore show a speed dependent angular distribution that is isotropic for the slow

Atomic-resolution electron microscopy is a crucial tool to elucidate the structure of matter. Recently, fast electron cameras have added the time domain to high-resolution imaging, allowing static images to be acquired as movies from which sample drift can ...

The dynamics following the photoexcitation of Na and Li atoms located on the surface of helium nanodroplets has been investigated in a joint experimental and theoretical study. Photoelectron spectroscopy has revealed that excitation of the alkali atoms via the (n + 1)s ns transition leads to the desorption of these atoms. The mean kinetic energy of the desorbed atoms, as determined by ion imaging, shows a linear dependence on excitation frequency. These experimental findings are analyzed within a three-dime

Reshaping plasmonic nanoparticles with laser pulses has been extensively researched as a tool for tuning their properties. However, in the absence of direct observations of the processes involved, important mechanistic details have remained elusive. Here, ...

Electronic spectra of molecules in helium droplets reveal spectral features that are related to the elementary excitations of the superfluid helium environment. In order to determine to what extend the interaction strength of the molecule with the helium a ...

The dynamics of Na atoms on the surface of helium nanodroplets following excitation via the 3p

Modern lasers now routinely allow experiments where large populations of highly excited molecules can be prepared with perfect quantum state selection. In a sense, the laser has become the physical chemist’s synthetic tool, allowing “optical distillation” of chemical reactants in the most purified form imaginable, individual quantum states. This article describes applications from the authors’ laboratory of these methods to studies in chemical reaction dynamics. A detailed description of the PUMP, DUMP, and

Interatomic processes play a crucial role in weakly bound complexes exposed to ionizing radiation; therefore, gaining a thorough understanding of their efficiency is of fundamental importance. Here, we directly measure the timescale of interatomic Coulombi ...

The recent development of ultrafast extreme ultraviolet (XUV) coherent light sources bears great potential for a better understanding of the structure and dynamics of matter. Promising routes are advanced coherent control and nonlinear spectroscopy schemes ...

The relaxation of photoexcited nanosystems is a fundamental process of light–matter interaction. Depending on the couplings of the internal degrees of freedom, relaxation can be ultrafast, converting electronic energy in a few fs, or slow, if the energy is ...

High-intensity extreme ultraviolet (XUV) pulses from a free-electron laser can be used to create a nanoplasma in clusters. In reference Michiels et al (2020 Phys. Chem. Chem. Phys. 22 7828-34) we investigated the formation of excited states in an XUV-induc ...

Fully rotationally resolved spectra of the two lowest-frequency bands ~the origin (00 0 ) and the inversion (140 1) band! of the S1(n p*)ÃS0 transition of jet-cooled (Trot'6 K) acetaldehyde, CH3CHO, have been recorded with a resolution of '0.01 cm21 using a pulsed dye amplified continuous wave ~cw! laser. In modeling the spectra a nonperturbative solution of the rotational– torsional coupling problem was used, but the torsion–inversion and the rotation–inversion couplings were neglected. All the lines of th

Sample preparation remains a bottleneck for protein structure determination by cryo-electron microscopy. A frequently encountered issue is that proteins adsorb to the air–water interface of the sample in a limited number of orientations. This makes it challenging to obtain high-resolution reconstructions, or may even cause projects to fail altogether. We have previously observed that laser flash melting and revitrification of cryo-EM samples reduces preferred orientation for large, symmetric particles. Here

Marcel Drabbels

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High-Resolution Transmission Electron Microscopy with Bright Microsecond Electron Pulses

Microsecond melting and revitrification of cryo samples

Characterization of a time-resolved electron microscope with a Schottky field emission gun

Sign of the state-to-state steric asymmetry of rotationally inelastic atom-molecule collisions

Decay of oriented Rydberg wave packets excited with far-infrared radiation

Critical Landau velocity in helium nanodroplets

Conformational flexibility of a rotaxane thread probed by electronic spectroscopy in helium nanodroplets

Imaging the Translational Dynamics of CF3 in Liquid Helium Droplets

Atomic-Resolution Imaging of Fast Nanoscale Dynamics with Bright Microsecond Electron Pulses

Desorption of alkali atoms from 4He nanodroplets

In Situ Observation of Coulomb Fission of Individual Plasmonic Nanoparticles

Elementary Excitations of Superfluid Helium Droplets Probed by Ion Spectroscopy

Excitation of Sodium Atoms Attached to Helium Nanodroplets: The 3p

Collisions and Chemistry of Super-Excited Molecules: Experiments Using the PUMP - DUMP - PROBE Technique

Ultrafast Resonant Interatomic Coulombic Decay Induced by Quantum Fluid Dynamics

Tracking attosecond electronic coherences using phase-manipulated extreme ultraviolet pulses

Ultrafast relaxation of photoexcited superfluid He nanodroplets

Evolution and ion kinetics of a XUV-induced nanoplasma in ammonia clusters

Rotational analysis of the origin and the inversion bands in the S1 (A2) ¬ S 0 (A1) electronic spectrum of acetaldehyde

Laser flash melting cryo-EM samples to overcome preferred orientation