A velocity map imaging photoelectron spectrometer for the study of ultrafine aerosols with a table-top VUV laser and Na-doping for particle sizing applied to dimethyl ether condensation
| Autor: | Adam H. C. West, Bernhard Schläppi, Egor Chasovskikh, Ruth Signorell, Bruce L. Yoder |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Methyl Ethers
Surface Properties Ultraviolet Rays Photoemission spectroscopy Analytical chemistry General Physics and Astronomy 010402 general chemistry 01 natural sciences Spectral line chemistry.chemical_compound Ionization 0103 physical sciences Physics::Atomic and Molecular Clusters Dimethyl ether Particle Size Physical and Theoretical Chemistry Aerosols 010304 chemical physics Spectrometer Chemistry Lasers Photoelectron Spectroscopy Sodium 0104 chemical sciences Aerosol Particle size Ionization energy |
| Zdroj: | Journal of Chemical Physics The Journal of Chemical Physics, 138 (4) The Journal of chemical physics |
| ISSN: | 0021-9606 1089-7690 |
| DOI: | 10.3929/ethz-b-000064622 |
| Popis: | We present a new experimental configuration for the study of size-dependent, angle-resolved photoelectron and photoion spectra of weakly bound ultrafine aerosol particles targeted at particle sizes below ∼20 nm. It combines single photon ionization by a tunable, table-top vacuum ultraviolet laser at energies up to 18 eV with velocity map imaging detection and independent size determination of the aerosol particles using the Na-doping method. As an example, the size-dependence of the valence photoelectron spectrum of dimethyl ether clusters and ultrafine aerosols is investigated. Up to a mean particle diameter of ∼3–4 nm, the first ionization energy (value at band maximum) decreases systematically (up to ∼1 eV) and the corresponding band broadens systematically (up to a factor of ∼3) with increasing aggregate size. Plateau values for band positions and bandwidths are reached beyond a diameter of ∼3–4 nm. Experimental evidence for the dominance of the fast intermolecular proton transfer over monomer fragmentation reactions upon ionization is presented via photoion imaging. The Journal of Chemical Physics, 138 (4) ISSN:0021-9606 ISSN:1089-7690 |
| Databáze: | OpenAIRE |
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