A5032930551- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Molecular spectroscopy and chirality
- Advanced Chemical Physics Studies
- Advanced X-ray Imaging Techniques
- Medical Imaging Techniques and Applications
- Photochemistry and Electron Transfer Studies
- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Molecular Spectroscopy and Structure
- Quantum, superfluid, helium dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Therapy and Dosimetry
- Electron and X-Ray Spectroscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Lanthanide and Transition Metal Complexes
- Advanced Fluorescence Microscopy Techniques
Heriot-Watt University
2020-2025
Radboud University Nijmegen
2024
Radboud University Medical Center
2024
Radboud Institute for Molecular Life Sciences
2024
We present an initial demonstration of a velocity-map imaging (VMI) experiment using back-irradiation laser-based desorption source directly integrated into the electrode assembly. This has potential to greatly expand utility popular VMI approach by permitting its use with high density plumes non-volatile molecular samples. Photoelectron circular dichroism measurements on phenylalanine molecule 400 nm multiphoton ionization are used illustrate this novel method, revealing forward-backward...
Many charged particle imaging measurements rely on the inverse Abel transform (or related methods) to reconstruct three-dimensional (3D) photoproduct distributions from a single two-dimensional (2D) projection image. This technique allows for both energy- and angle-resolved information be recorded in relatively inexpensive experimental setup, its use is now widespread within field of photochemical dynamics. There are restrictions, however, as cylindrical symmetry constraints overall form...
Femtosecond pulses of light in the vacuum ultraviolet (VUV) spectral region permit extended observation non-adiabatic dynamics gas-phase molecules. When used as a probe time-resolved photoelectron spectroscopy, such project deeply into ionization continuum and allow evolution excited state population to be monitored across multiple potential energy surfaces. compared with longer-wavelength probes, this often provides more complete view along reaction coordinate(s) connecting photoreactants...
Examples of extracting meaningful information from image projection data using tomographic reconstruction techniques can be found in many areas science. Within the photochemical dynamics community, tomography allows for complete three-dimensional (3D) charged particle momentum distributions to reconstructed following a photodissociation or photoionization event. This permits highly differential velocity- and angle-resolved measurements made simultaneously. However, generalized strategies...
Photoelectron angular distributions (PADs) produced from the photoionization of chiral molecules using elliptically polarized light exhibit a forward/backward asymmetry with respect to optical propagation direction. By recording these velocity-map imaging (VMI) technique, resulting photoelectron elliptical dichroism (PEELD) has previously been demonstrated as promising spectroscopic tool for studying in gas phase. The use laser pulses, however, produces PADs (and consequently, PEELD...
A new method for the fully generalized reconstruction of three-dimensional (3D) photoproduct distributions from velocity-map imaging (VMI) projection data is presented. This approach, dubbed Fourier–Hankel–Abel Nyquist-limited TOMography (FHANTOM), builds on recent previous work in tomographic image [C. Sparling and D. Townsend, J. Chem. Phys. 157, 114201 (2022)] takes advantage fact that produced typical VMI experiments can be simply described as a sum over small number spherical harmonic...
We demonstrate the efficient transfer of population between rotational levels ND3 using a commercially available table-top THz source. use Stark decelerator to prepare packet para-ND3 molecules in 11− upper inversion component ground state, and induce 21+←11− electric dipole allowed transition both presence an field under free conditions. Using chirps address all hyperfine components, efficiencies up 87% are reached, limited by power Population from 21− level is demonstrated either driving...
Abstract We present the first demonstration of artificial neural networks (ANNs) for removal Poissonian noise in charged particle imaging measurements with very low overall counts. The approach is successfully applied to both simulated and real experimental image data relating detection photoions/photoelectrons unimolecular photochemical dynamics studies. Specific examples consider multiphoton ionization pyrrole ( S )‐camphor. Our results reveal an extremely high level performance, ANNs...