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Article
High-resolution mass spectrometric study of pure helium droplets, and droplets doped with krypton
Mass spectra of doped and undoped helium droplets are presented. The high resolution of the time-of-flight spectrometer (m/Δm ≅ 5000) makes it possible to fully resolve small helium cluster ions from impurities ...
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Article
Use of proton transfer reaction time-of-flight mass spectrometry for the analytical detection of illicit and controlled prescription drugs at room temperature via direct headspace sampling
The first reported use of proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) for the detection of a range of illicit and prescribed drugs is presented here. We describe the capabilities of ...
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Article
Proton transfer reaction mass spectrometry for the sensitive and rapid real-time detection of solid high explosives in air and water
Relying on recent developments in proton transfer reaction mass spectrometry (PTR-MS), we demonstrate here the capability of detecting solid explosives in air and in water in real time. Two different proton tr...
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Article
A detailed study on the decomposition pathways of the amino acid valine upon dissociative electron attachment
In the present study we investigate free electron attachment to the amino acid valine. Mass spectra and anion efficiency curves are measured in the electron energy range from about zero eV to about 15 eV and ...
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Article
Electron attachment to doped helium droplets: C60 -, (C60)2 -, and C60D2O- anions
Helium nanodroplets, formed in a supersonic expansion, are doped with C60 in a pickup cell. In some experiments, they are co-doped with water. Electrons are attached to the doped droplets; the yield of anions is ...
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Article
Electron impact ionization studies with the amino acid valine in the gas phase and (hydrated) in helium droplets
Here we report electron impact ionization studies with the amino acid valine in different environments, i.e., (i) isolated in the gas phase, (ii) embedded in superfluid helium droplets and (iii) co-embedded wi...
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Article
Open AccessButter and butter oil classification by PTR-MS
The potential of proton transfer reaction mass spectrometry (PTR-MS) as a tool for classification of milk fats was evaluated in relation to quality and authentication issues. Butters and butter oils were subje...
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Article
Isotope effects in the metastable decay of Ne2 +
Neon dimer ions undergo spontaneous dissociation (metastable decay) several microseconds after formation by electron impact ionization of neon clusters. In this contribution we compare the kinetic energy re...
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Article
Electron impact ionization of thymine clusters embedded in superfluid helium droplets
Embedding molecules in helium clusters has become a powerful technique for the preparation of cold targets for spectroscopy experiments, as well as for the assembly of complex, fragile molecular species. We...
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Article
Newly calculated absolute cross-section for the electron-impact ionization of C2H2 +
New measurements of the cross-section for electron impact ionization of the molecular ion C2H2 + have been carried out recently. These data differ significantly from earlier data, becaus...
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Article
Positive and negative ion formation via slow electron collisions with 5-bromouridine
Cation and anion formation is studied experimentally upon inelastic low energy electron interactions with 5-bromouridine (BrUrd) using a crossed electron/neutral beams set-up combined with a quadrupole mass ...
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Chapter
High resolution electron interaction studies with atoms, molecules, biomolecules and clusters
Ionisation and attachment by electrons are two of the most fundamental inelastic electron collision processes. Electron-impact ionisation/attachment processes are also important in many practical applications ...
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Chapter
Partial and Differential Electron Impact Ionization Cross-Sections for Small Hydrocarbon Molecules
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Article
Dissociative electron attachment to gas-phase glycine
By using a high-resolution electron energy monochromator low-energy electron attachment to gas-phase glycine (H2NCH2COOH, or G) has been studied by means of mass spectrometric detection of the product anions. In ...
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Article
Energetics and dynamics of decaying cluster ions
The recent addition of (i) a third sector field to our two sector field mass spectrometer (resulting in a BE1E2 field configuration) and of (ii) a high performance electron gun enables us now to study in detai...
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Article
The Rate Constant for Dissociative Electron Attachment to Ozone Revisited
The rate constant for dissociative electron attachment to ozone has been derived over the energy range from about 0 to 10 eV using recently measured and also corrected cross section data. The new rate constant...
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Article
Low energy electron attachment to formic acid
Using a high resolution electron energy monochromator low energy electron attachment to formic acid is studied for the first time by means of mass spectrometric detection of the product anions. The largest dis...
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Article
Inelastic interactions of protons and electrons with biologically relevant molecules
Ionization and fragmentation of water and uracil molecules was studied both by electron and proton impact. A special coincidence technique allows on an event by event basis the investigation of product ions fo...
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Article
Decay reactions of rare gas cluster ions: Kinetic energy release distributions and binding energies
We have carried out measurements on metastable fragmentation of mass selected argon cluster ions which are produced by electron impact ionization of a neutral argon cluster beam. From the shape of the fragment...
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Chapter
Electron Attachment to Oxygen and Nitric Oxide Clusters
Electron attachment studies are of fundamental importance to the understanding of electron-molecule and electron-cluster interaction and the mechanisms of negative ion formation. In addition, these studies are...
