Download or read book Molecular Studies Using Resonance Enhanced Multiphoton Ionization written by Jeffrey Matos and published by . This book was released on 2006 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resonance Enhanced Multiphoton Ionization Spectra of Molecules and Molecular Fragments Annual Technical Report written by and published by . This book was released on 1997 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance Enhanced Multiphoton Ionization (REMPI) utilizes pulsed laser radiation to prepare a molecule in an excited state via absorption of one or more photons and to subsequently ionize that state before it can decay. A remarkable feature of REMPI, and one that is very basic to many of its applications and uses, is that the very narrow bandwidth of the {open_quotes}pump{close_quotes} laser makes it possible to select a specific vibrational and rotational level in the initial state and to prepare the excited state of interest in a single vibrational and rotational level. Thus, by suitable choice of the photon pump transition, it is possible to selectively ionize a species of interest without ionizing any other species that might be present. This feature makes REMPI one of the most powerful tools for ultrasensitive detection of species. With REMPI it is also possible to study the photoionization dynamics of a single rotational level of an excited electronic state. Such state-resolved studies can certainly be expected to provide significant insight into the underlying dynamics of molecular photoionization.
Download or read book Resonance Enhanced Multiphoton Ionization of Molecules and Molecular Fragments written by and published by . This book was released on 1994 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have completed studies of ion rotational distributions produced by resonance enhanced multiphoton ionization of excited states of molecules and by single-photon ionization of ground states of jet-cooled molecules by coherent VUV radiation. The objective of this effort was to provide a robust analysis and prediction of key spectral features of interest in related experimental studies and technological applications of these laser-driven ionization techniques. Specific achievements include: identification of underlying mechanisms for anomalous behavior of ion rotational distributions in laser ionization of molecules and molecular fragments, development of schemes for exploiting such anomalous behavior to achieve state-selective production of ions, and providing needed insight into the underlying dynamics of state-resolved molecular photoionization.
Download or read book Studies of Resonantly Enhanced Multiphoton Ionization Processes in Molecules written by and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies were completed of several Resonance Enhanced Multiphoton Ionization (REMPI) processes in molecules. The overall objective of this effort was to provide a robust theoretical analysis and prediction of the key spectral features associated with various experimental and technology applications of this technique including its use for state-specific detection and production of species and for diagnostics in combustion and processing plasmas. Specific achievements of this research included: (1) studies of ion vibrational distributions produced by REMPI with emphasis on anomalous behavior in these distributions in molecules and molecular fragments, e.g. OH and CF; (2) ion rotational distributions that results from REMPI, the underlying dynamics of these processes, and the identification of schemes for enhancing state selectivity in these distributions; (3) use of photoelectron angular distributions produced by REMPI to probe molecular alignment, an important dynamical feature in gas-surface collisions and molecular fragmentation.
Download or read book Resonance Enhanced Multiphoton Ionization Spectra of Molecules and Molecular Fragments Annual Technical Report March 1991 February 1992 written by and published by . This book was released on 1993 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance Enhanced Multiphoton Ionization (REMPI) utilizes pulsed laser radiation to prepare a molecule in an excited state via absorption of one or more photons and to subsequently ionize that state before it can decay. The overall objective of this effort is to carry out theoretical studies of these REMPI processes in molecules and molecular fragments which are designed to provide a robust analysis and prediction of key spectral features of interest in several experimental studies and applications of this technique. A specific and very important objective of the effort is to predict the vibrational and rotational ion distributions which result from REMPI of representative molecules and to understand the underlying mechanisms that give use to these ion distributions. The author highlights progress made during this period.
Download or read book Resonance Enhanced Multiphoton Ionization Spectra of Molecules and Molecular Fragments Annual Progress Report March 1992 February 1993 written by and published by . This book was released on 1993 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report, the author will review the progress made in his studies of ion rotational distributions resulting from resonance enhanced multiphoton ionization of excited electronic states and from single-photon ionization of ground electronic states of jet-cooled molecules by coherent VUV and XUV radiation. To do so he will select a few examples from his studies which serve to highlight his progress and to identify the background and significance of the specific spectral features and systems he has chosen to study.
Download or read book Experimental REMPI Resonance Enhanced Multiphoton Ionization Studies of Small Molecules written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance Enhanced Multiphoton Ionization (REMPI) utilizes tunable dye lasers to ionize an atom or molecule by first preparing an excited state by multiphoton absorption and then ionizing that state before it can decay. This process is highly selective with respect to both the initial and resonant intermediate states of the target, and it can be extremely sensitive. In addition, the products of the REMPI process can be detected as needed by analyzing the resulting electrons, ions, fluorescence, or by additional REMPI. This points to a number of exciting opportunities for both basic and applied science. On the applied side, REMPI has great potential as an ultrasensitive, highly selective detector for trace, reactive, or transient species. On the basic side, REMPI affords an unprecedented means of exploring excited state physics and chemistry at the quantum-state-specific level. We shall give an overview together with examples of current studies of excited molecular states to illustrate the principles of and prospects for REMPI. 27 refs., 3 figs.
Download or read book Photoionization and Photo Induced Processes in Mass Spectrometry written by Ralf Zimmermann and published by John Wiley & Sons. This book was released on 2021-07-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides comprehensive coverage of laser-induced ionization processes for mass spectrometry analysis Drawing on the expertise of the leading academic and industrial research groups involved in the development of photoionization methods for mass spectrometry, this reference for analytical scientists covers both the theory and current applications of photo-induced ionization processes. It places widely used techniques such as MALDI side by side with more specialist approaches such as REMPI and RIMS, and discusses leading edge developments in ultrashort laser pulse desorption, to give readers a complete picture of the state of the technology. Photoionization and Photo-Induced Processes in Mass Spectrometry: Fundamentals and Applications starts with a complete overview of the fundamentals of the technique, covering the basics of the gas phase ionization as well as those of laser desorption and ablation, pulse photoionization, and single particle ionization. Numerous application examples from different analytical fields are described that showcase the power and the wide scope of photo ionization in mass spectrometry. -The first general reference book on photoionization techniques for mass spectrometry -Examines technologies and applications of gas phase resonance-enhanced multiphoton ionization mass spectrometry (REMPI-MS) and gas phase resonance ionization mass spectrometry (RIMS) -Provides complete coverage of popular techniques like MALDI -Discusses the current and potential applications of each technology, focusing on process and environmental analysis Photoionization and Photo-Induced Processes in Mass Spectrometry: Fundamentals and Applications is an excellent book for spectroscopists, analytical chemists, photochemists, physical chemists, and laser specialists.
Download or read book Resonance Enhanced Multiphoton Ionization Spectra of Molecules and Molecular Fragments Technical Report January 1990 December 1990 written by and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of our effort is to carry out theoretical studies of resonance enhanced multiphoton ionization processes in molecules and molecular fragments. These studies are designed to provide a quantitatively robust analysis and prediction of key spectral features of interest in several ongoing experimental studies and applications of this technique.
Download or read book Resonance Enhanced Multiphoton and Single photon Ionization of Molecules and Molecular Fragments Final Report May 1993 April 1997 written by and published by . This book was released on 1998 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance enhanced multiphoton ionization (REMPI) utilizes pulsed laser radiation to prepare a molecule in an excited state via absorption of one or more photons and to subsequently ionize that level before it decays. A remarkable feature of REMPI is that the very narrow bandwidth of laser radiation makes it possible to select a specific rotational level in the initial (ground) state and to prepare the excited state of interest in a single rotational level. Thus, by suitable choice of the excitation step, it is possible to selectively ionize a species that may be present. The key objective of the effort is to carry out quantitative studies of REMPI of molecules and molecular fragments, as well as of single-photon ionization of these species by coherent VUV radiation, in order to provide a robust description of significant spectral features of interest in related experiments and needed insight into the underlying dynamics of these spectra. A major focus of the effort is joint theoretical and experimental studies of these ion rotational distributions which are being widely studied by the zero-kinetic-energy (ZEKE) technique. This technique, which is based on the detection of photoelectrons resulting from pulsed-field ionization of very high Rydberg states lying just below an ion threshold, makes it possible to obtain cation distributions with subwavenumber resolution. The unprecedented resolution of this ZEKE technique is opening up entirely new vistas in studies of photoionization dynamics, ion spectroscopy, and state-selected ion-molecule reactions. Emerging applications built on the ultra-high resolution of this technique include its use for accurate determination of thermochemically important ionization energies, for characterization of ion rovibrational level structure of large organic molecules, of elemental clusters, and of weakly bound molecular complexes, for probing reactive fragments, and for pump-probe photoelectron studies of wavepacket dynamics. This surge of experimental activity in ultra-high resolution studies of molecular photoelectron spectra continues to raise new theoretical challenges and has provided the stimulus for several of the collaborations with experimental groups in North America and Europe.
Download or read book Resonance Enhanced Multiphoton and Single photon Ionization of Molecules and Molecular Fragments Annual Technical Report May 1 1994 April 30 1995 written by and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: In resonance enhanced multiphoton ionization (REMPI) pulsed laser radiation is utilized to prepare a molecule in an excited state via absorption of one or more photons and to subsequently ionize that level before it decays. A remarkable feature of REMPI is that the very narrow bandwidth of laser radiation makes is possible to select a specific rotational level in the initial (ground) state and to prepare the excited state of interest in a single rotational level. By suitable choice of the excitation step, it is thus possible to selectively ionize a species of interest present in very minor concentrations without ionizing any other species that may be present. This feature makes REMPI a very powerful tool for ultrasensitive detection of trace or transient species.
Download or read book Resonance Enhanced Multiphoton Ionization Spectra of Molecules and Molecular Fragments and Femtosecond Energy and Angle Resolved Pump Probe Photoelectron Spectra written by Vincent McKoy and published by . This book was released on 1998 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have completed studies of ion rotational distributions produced by resonance multiphoton ionization of molecules, molecular fragments and small clusters such as NaH2O and NaNH3. Our key objective was to provide a robust analysis and prediction of spectral features of interest in related experimental studies and technological applications of laser driven ionization. We have also extended our studies of photoelectron spectroscopy from the energy domain to the ultrafast time domain with an emphasis on exploiting femtosecond energy- and angle-resolved photoelectron spectra for real-time mapping of wavepacket motion in molecular systems. We have developed a formulation of time-resolved photoelectron spectroscopy that is well suited for such applications. Results of applications provide compelling evidence of the unprecedented insight that such spectra can provide into both wavepacket motion and the evolution of the associated electronic structure. This capability shows significant promise as a probe of wavepacket motion in regions of avoided crossings (nonadiabatic behavior).
Download or read book Molecular Spectroscopy and Dynamics of Reactive Chemical Intermediates Studied Using Laser Induced Flourescence LIF Single Vibronic Level SVL Emission and Resonance Enhanced Multiphoton Ionization REMPI Spectrometry written by Lloyd Godfrey Muzangwa and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the studies of complex chemical processes, it is necessary to postulate mechanisms involving transient intermediates such as radicals, ions, and pre-reactive complexes. The detection and characterization of these intermediates affords in ideal cases determination of the detailed chemical mechanism, which, in turn, can permit the development of rational strategies for removing undesired products and enhancing the yield of the desired species. This dissertation describes spectroscopic study of transient molecules and molecular complexes. Laser Induced Fluorescence (LIF), Single Vibronic Level (SVL) emission and Resonance Enhanced Multiple Photon Ionization (REMPI) spectroscopy has been used to probe the electronic states of NiI, NiBr, NiCl, CCN and chlorobenzene clusters (ClBz)n where n = 1-4. In this work, term energies and a complete set of vibrational parameters were derived for all the electronic states accessible for NiI, NiBr, NiCl and CCN. These vibrational parameters were compared to the recent high level ab initio calculations. REMPI spectra of chlorobenzene clusters formed in a He/Ar supersonic jet were obtained. Different types of non-covalent interactions (Ã{u0192}Æ{u2019}Ã{u201A}°-Ã{u0192}Æ{u2019}Ã{u201A}° stacking, CH/Ã{u0192}Æ{u2019}Ã{u201A}° interactions, and halogen bonding) were found to be in operation in the ClBz clusters. To rationalize the experimental results, the clusters were characterized computationally using Density Functional Theory (DFT) and Time-Dependent DFT methods in combination with correlation consistent basis sets.
Download or read book Structural Studies of Cyclic Ketones Cooled in a Molecular Beam Studied by Resonance Enhanced Multiphoton Ionization Through the Intermediate 3s Rydberg State written by Timothy J. Cornish and published by . This book was released on 1987 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Resonance enhanced Multiphoton Ionization System written by P. D. Naik and published by . This book was released on 2009 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances In Multi photon Processes And Spectroscopy Vol 4 written by Sheng-hsien Lin and published by World Scientific. This book was released on 1988-05-01 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents:Two-Color Double Resonance Spectroscopy For the Study of High Excited States of Molecules (M Ito & M Fujii)Resonantly Enhanced Multiphoton Ionization — Photoelectron Spectroscopy as a Probe of Molecular Photophysics and Photochemistry (S Pratt, P Dehmer & J Dehmer)Progress in Resonance Enhanced Multiphoton Ionization Spectroscopy of Transient Free Radicals (J Hudgens)Time-Resolved Resonance Raman Spectroscopy: Intense Electromagnetic Field Effects, and Photoelectrochemical Reactions on Semiconductor Crystallite Surfaces (L Brus) Readership: Atomic physicists, chemists and materials scientists.
Download or read book High Resolution Spectroscopy and Dynamics of Multiphoton Processes in Atoms and Molecules written by P. M. Dehmer and published by . This book was released on 1984 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes research on resonantly enhanced multiphoton absorption dissociation, and ionization processes in atoms and molecules. Multiphoton processes are studied using from one to three independently tunable visible and/or UV laser beams in order to establish both the underlying physics and the high degree of selectivity of multiphoton processes. Measurements are made to probe both the formation of excited molecular states and the subsequent behavior of excited states either in the presence or in the abscence of further intense laser radiation. Detection methods include laser-induced fluorescence, ion mass analysis, and electron energy analysis. During the current reporting period, we have studied resonant multiphoton ionization processes for the molecules N2, CO, O2, NO, NeXe, ArXe, KrXe, and Xe2 and for the atoms C, I, and S using both mass spectrometry and photoelectron spectroscopy to analyze the products of the ionizations. In addition, we are developing three new instruments that will provide significantly enhanced resolution, collection efficiency, and versatility in both the ion mass and the electron kinetic energy detection channels. Keywords include: double resonance spectroscopy, electron spectroscopy, molecular beams, rydberg states; photoelectron angular, distributions. (Author).
