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Showing 1 to 20 of 26 for “"multiphoton ionization"”.
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Multiphoton ionization photoelectron spectroscopy of iodine-bearing molecules
Multiphoton ionization of iodine-bearing molecules has been studied, under collision-free conditions, by observing the kinetic energy of the ejected photoelectrons. These experiments have demonstrated that, for photoionization of I$\sb2$, CF$\sb3$I and HI at 532 nm, the scission of the R-I bond …
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Multiphoton ionization of hydrogen iodide and molecular iodine using photoelectron spectroscopy
… time-of-flight photoelectron spectroscopy using multiphoton ionization techniques. At a pumping wavelength of 532 nm, it was concluded that dissociation due to the intermediate repulsive valence states is very strong for both HI and I$\sb2.$ For HI, the dissociative valence states correlate with …
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Optical Processes in Xenon: Multiphoton Ionization and Ultraviolet Photodissociation of the Dimer Ion
The coefficient for two-photon ionization of xenon at 193 nm has been measured using a microwave absorption scheme which determines peak electron densities. The electron-neutral collision frequency, (nu)(,m), has been obtained using a microwave bridge and the result is consistent with 0.7 eV …
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Optical processes in xenon: Multiphoton ionization and ultraviolet photodissociation of the dimer ion
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-09T18:07:47Z No. of bitstreams: 1 1983_mccown.pdf: 2864187 bytes, checksum: 4f71cae5d24766c4f3268969775f4bf4 (MD5)
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Investigation of Resonant Enhanced Multiphoton Ionization of Solid State High Explosives With Laser Ablation
… presents investigations of resonant enhanced multiphoton ionization of solid high explosives following laser desorption. This study is driven by the need for new, fast and reliable in-situ detection techniques for hazardous materials such as high explosives, in order to reduce the danger of …
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Multiphoton ionization and photoelectron spectroscopy of hydrogen iodide with fixed wavelength and tunable laser sources
Multiphoton ionization of the hydrogen iodide molecule has been examined by photoelectron spectroscopy. The fixed wavelength experiments, at 355 nm and optical intensities of $\sim$10$\sp{12}$ W/cm$\sp2,$ reveal clear vibrational progressions associated with the $X\sp2\Pi$ spin-orbit split ion …
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Optical processes in Kr and Kr2f, absolute cross sections for multiphoton ionization of Kr(1S0), photoionization of metastastable Kr* and Kr2*, and absorption of Kr2F (42gamma)
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-03T14:11:37Z No. of bitstreams: 1 1986_geohegan.pdf: 6764728 bytes, checksum: 84a3b6ee81b8c90530bf9c9c178782cb (MD5)
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Mass selective investigations of ultrafast dynamical processes and spectroscopy
… atoms are explored by Resonantly-Enhanced Multiphoton Ionization (REMPI) with Time-of-Flight mass spectrometric (TOFMS) detection.
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Damages in Transparent Materials by Ultrashort Laser Pulse
… underlying mechanism of electron generation by multiphoton ionization and avalanche ionization is numerically investigated. The multiphoton ionization rate and avalanche ionization rate are determined by fitting experimental results. The relative role of multiphoton ionization and avalanche …
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Investigating multiphoton phenomena using nonlinear dynamics
… thesis, we report our theoretical analyses on multiphoton ionization of Rydberg atoms exposed to strong microwave fields and the dissociation of diatomic molecules exposed to bichromatic lasers using nonlinear dynamical tools. This thesis is composed of three subtopics. In the first subtopic, …
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In-situ laser tagging of barium ions in liquid xenon for the EXO experiment
… ions. An unexpected discovery of the nonresonant multiphoton ionization of liquid xenon using pulsed UV lasers was made while characterizing the purity monitor. The discovery was vital to the ability to accurately measure the purity of the liquid xenon. The spectroscopy of Ba+ ions in liquid xenon …
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Optical Processes in Krypton and Krypton(2)fluoride: Absolute Cross-Sections for Multiphoton Ionization of Krypton (1S(0)), Photoionization of Metastable Atomic and Molecular States of Krypton, Andabsorption of Krypton(2)fluoride (4-Doublet-Gamma)
… for the three-photon, resonantly-enhanced ionization of Kr(('1)S(,0)) at 193 nm. The presence of a two-photon resonance with the Kr 6p 3/2 (,2) level enabled the generation of large electron densities and a measurement of the two-photon absorption cross section. A similar technique was …
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Two photon and two colour ionization of atoms in intense extreme-UV and optical laser fields
Inner shell ionization and excitation in atoms has been studied extensively for many decades using a variety of ultraviolet and X-ray light sources, especially, but not exclusively, synchrotrons. In addition, the study of multiphoton absorption by outer (valence) electrons rapidly followed the …
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Πολυφωτονική φασματοσκοπία του Sr-αυτοϊονιζόμενες καταστάσεις με J=3 και διπλός ιονισμός
… We have recorded energy level positions and autoionization widths of the odd pavity J=3 states of Sr, in the energy range. Between the 5S1/2 and 4D3/2, 5/2 ionization limits. The analysis of the spectra showed that strong perturbations exist among Rydberg series converging in different limits. B) …
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Multiphoton laser spectroscopy of indium monoiodide
The laser induced fluorescence (LIF) and the multiphoton ionization (MPI) spectra of indium monoiodide have been obtained at ultraviolet and visible wavelengths. Fluorescence from excited indium atoms at 451.1 nm (6s $\sp2$S$\sb{1/2}$ $\to$ 5p $\sp2$P$\sb{3/2}$) is produced by the multiphoton …
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ΦΑΣΜΑΤΟΣΚΟΠΙΑ ΔΙΕΓΕΡΜΕΝΩΝ ΗΛΕΚΤΡΟΝΙΑΚΩΝ ΚΑΤΑΣΤΑΣΕΩΝ ΤΩΝ ΠΙΚΟΛΙΝΩΝ
… 1 AND 12. FINALLY, THROUGH THE RESONANT MULTIPHOTON IONIZATION SPECTRA IN A STATIC CELL AND IN A SUPERSONIC BEAM, WE STUDIED 3S RYDBERG STATE AND WE ANALYSED ITS VIBRATIONAL STRUCTURE. THAT ANALYSIS PROVIDED SERIOUS INDICATIONS THAT THE HIGHER OCCUPIED MOLECULAR ORBITAL IS A Π-TYPE ONE IN …
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Which way did it go? Revisiting the time-resolved study of bromine atom and iodine molecule
… The method of detection, Resonance Enhanced Multiphoton Ionization (REMPI)-Time of Flight Mass Spectroscopy (TOFMS), allows unambiguous identification of products. The interaction is initiated in a restricted region of phase space defined by the geometry of the precursor dimer, H(D)Br$\rm\sp …
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Spectroscopy of Ultracold LiRb Molecules Using Ionization Detection
… studies of ultracold LiRb molecules using ionization detection. The molecules are created by cooling and trapping Li and Rb atoms in overlapping magneto-optical traps (MOTs) and using light resonant with a free-bound transition to create weakly bound excited state molecules in a process …
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The Development of a Novel Femtosecond Xuv Light Source to Do Spectroscopy of Atoms and Molecules.
… light-matter interaction. As a consequence, Multiphoton Ionization (MPI), Above Threshold Ionization, and High Order Harmonic Generation (HOHG) are the primary phenomena associated with this special interaction. High order harmonic generation (HOHG) is a promising way to generate usable short …
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The spectroscopy of bound and predissociating Rydberg states of NO in external electric fields
… Chapter 3 describes the structure of NO and multiphoton excitation scheme utilised for the work presented in this thesis. Chapter 4 investigates the effect of applied DC electric fields in the range 0 – 150 V cm-1 on the predissociating Rydberg states of NO below the υ+ = 0 ionisation limit, …
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