Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 95 for “"Photoionization"”.
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Photoionization of laser excited barium
"Absolute cross sections for photoionization of the 6s6p ¹P excited state of barium were measured over the range 420 - 368 nm. This range includes threshold as well as numerous autoionizing resonances resulting from excitation to discrete states embedded in the ionization continuum. The experiments …
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Laser induced photoionization of helium
Thesis: B.S., Massachusetts Institute of Technology, Department of Physics, 1980
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Furanic Molecules: Multiplexed Synchrotron Photoionization Investigations and Aerosol Studies
… in addition to the determination of the absolute photoionization cross-sections of 2EF, 2-acetylfuran, and furfural. These experiments are carried out using synchrotron photoionization mass spectrometry (SPIMS) with an orthogonal time-of-flight spectrometer used for mass analysis at the Advanced …
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Investigation of Absolute Photoionization Cross Sections of Cyclic Ketones, Low Temperature Combustion of Propargylamine by Synchrotron Photoionization Mass Spectrometry, and Computational Study of Hypersalts
… of San Francisco. Measurements of absolute photoionization cross sections of both cyclopentanone and cyclohexanone, as well as the Cl-initiated oxidation of propargylamine were completed through the use of a multiplexed photoionization mass spectrometer (MPMIS) located at the Lawrence …
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Photoionization and Photofragmentation of the Endohedral Xe@C60+ Molecular Ion
An experimental study of photoionization and fragmentation of the Xe@C60 + endohedral molecular ion is presented in the photon energy range of the well-known Xe 4d giant resonance, and evidence of redistribution of the Xe 4d oscillator strength in photon energy due to multipath interference is …
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Photoionization of the Cerium Isonuclear Sequence and Cerium Endohedral Fullerene
This dissertation presents an experimental photoionization study of the cerium isonuclear sequence ions in the energy range of the 4d inner-shell giant resonance. In addition, single and double photoionization and photofragmentation cross sections of the cerium endohedral ion Ce$@$C$_{82}^{+}$ were …
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Photoionization of atoms with ultrashort XUV laser pulses at extreme intensities
The present thesis is concerned with the photoionization dynamics of atoms exposed to high intense and ultrashort XUV-laser pulses of free-electron lasers. In particular, the influence of coherent dynamics of the electrons as well as the electron-electron interaction are in focus of this survey and …
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Photofragmentation of carbonyl sulfide (Ocs) following core-shell photoexcitation and photoionization
… of cations and anions after photoexcitation and photoionization of OCS in the vicinity of the S 2p, C 1s and O 1s thresholds. Singly charged cations are produced predominantly at the pi* and Rydberg resonances while dications are major products of dissociative channels above the thresholds. At …
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A krypton VUV photoionization source for gas chromatography and mass spectrometry.
… energies of 10.0 and 10.6 eV. When used as a photoionization mass spectrometer source, conditions can be created where molecular ions can be produced which do not undergo fragmentation. This effect can greatly simplify spectral interpretation in the case of either direct sample introduction or …
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Study of Plasmon Resonances in Single Photoionization of Carbon Fullerene Molecular Ions
… from 18-70 eV at 0.5 eV intervals. Single photoionization was studied over this energy range using a merged-beams research endstation at the Advanced Light Source and absolute photoionization cross sections were measured. Electric-dipole-excited surface and volume plasmon resonances due to …
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Aqueous photoionization of anionic 2'-deoxythmidine-5'-phosphate, 2'-deoxyguanosine and tryptophan.
Aqueous photoionization of anionic 2'-deoxythmidine-5'-phosphate, 2'-deoxyguanosine and tryptophan.
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Characterization of ETBE + Cl and Isooctane + Cl Combustion Products using Synchrotron Photoionization
… lab, using a multiplexed chemical kinetics photoionization mass spectrometer with tunable synchrotron radiation. Using Cl atoms as initiators in presence of oxygen, photoionization data were collected. Data analysis was performed via characterization of the reaction species photoionization …
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Photoionization of excited states of atomic hydrogen in a strong electric field
The photoionization of excited states of atomic hydrogen in a strong external electric field is examined theoretically and experimentally. A theoretical treatment which predicts novel effects in the excitation of the broad resonant states in the continuum from pure parabolic Stark states is …
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Photoionization of Se Ions for the Determination of Elemental Abundances in Astrophysical Nebulae
Absolute single photoionization cross section measurements are presented for Se+ ,Se2+, Se3+ and Se5+. These measurements were performed at undulator beamline 10.0.1 of the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the merged-beams technique. All ions except Se5+ …
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Cross sections for photoionization of the 6²P-fine structure levels of cesium
<p>"The cross sections for photoionization of excited cesium from the 6<sup>2</sup>P<sub>3/2</sub>- and 6²P<sub>1/2</sub>-fine structure levels have been measured using a triple crossed-beam apparatus. Two photon beams, one for excitation and one for ionization, impinge upon an atomic beam and …
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Photoionization Mass Spectrometry and Photoelectron-Photoion Coincidence (PEPICO) Spectroscopy Studies of Select Biofuel Molecules
… of the newly obtained data. It presents some photoionization mass spectrometry studies on γ-valerolactone (GVL). The photoionization cross section of GVL and some suspected combustion products are measured. In addition, several dissociative ions are determined. Theoretical calculations are …
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Photoionization and excitation of free variable size van der Waals clusters in the inner shell regime
… interaction. Complementary experiments on the photoionization of free van der Waals clusters are performed by using zero kinetic energy (ZEKE) photoelectron spectroscopy in the Ar 2p-, Kr 3d-, Ne 1s-, and N2-regimes. The experimental approach is also suitable to detect cluster size dependent …
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The Investigation of the Low Temperature Combustion of Mesitylene and Tert-Amyl Methyl Ether by Synchrotron Photoionization Mass Spectrometry
<p>This thesis describes the combustion experiments performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) located at the Lawrence Berkeley National Laboratories (LBNL). The need for renewable fuel sources, the need for the study of their combustion in the contexts of …
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The study of bimolecular radical reactions using a novel time-resolved photoionization time-of-flight mass spectrometry and laser absorption spectrometry apparatus
This thesis discusses my work to design, build, troubleshoot, and utilize a novel experimental apparatus that is capable of quantitatively measuring the concentrations of reacting gas-phase species and their reactive intermediates with sufficient time-resolution and sensitivity to determine both …
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Absolute molecular electronic spectroscopy at UV and soft X-Ray energies by hihg-energy electron impact
… employed to study the molecular and dissociative photoionization in the valence shell of CH3OH, and in the valence and inner shells of CC14. Time-of-flight mass spectroscopy is used to determine photoionization branching ratios and photoionization efficiencies. These data are combined with the …
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