Collision-induced Absorption in Gases PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Collision-induced Absorption in Gases PDF full book. Access full book title Collision-induced Absorption in Gases by Lothar Frommhold. Download full books in PDF and EPUB format.
Author: Lothar Frommhold
Publisher:
ISBN: 9780521393454
Category : Science
Languages : en
Pages : 410
Get Book Here
Book Description
This book reviews the theory and experiment of collision-induced absorption of infrared radiation in dense gases.
Author: Lothar Frommhold
Publisher:
ISBN: 9780521393454
Category : Science
Languages : en
Pages : 410
Get Book Here
Book Description
This book reviews the theory and experiment of collision-induced absorption of infrared radiation in dense gases.
Author: Douglas R. Bosomworth
Publisher:
ISBN:
Category : Gases
Languages : en
Pages : 172
Get Book Here
Book Description
Author: H. T. Yura
Publisher:
ISBN:
Category : Collisions (Nuclear physics)
Languages : en
Pages : 42
Get Book Here
Book Description
A quantum mechanical calculation is given for collision-induced absorption in the infrared and far-infrared spectral regions for mixtures consisting of symmetrical diatomic molecules and rare-gas atoms. The induced moment consists of a short-range overlap term and a long-range quadrupole term. Near molecular transition lines, the quadrupole term gives the main contribution to the absorption, while in the far wings, the overlap term is dominant. The H2-He, H2-Ar, N2-Ar systems are considered, and an estimate is given of the absorption coefficient near 10 millimicrons for N2-N2 systems. (Author).
Author: G.C. Tabisz
Publisher: Springer Science & Business Media
ISBN: 9401101833
Category : Science
Languages : en
Pages : 581
Get Book Here
Book Description
Collision-or interaction-induced spectroscopy refers to radiative transitions, which are forbidden in free atoms or molecules, but which occur in clusters of interacting atoms or molecules. The most common phenomena are induced absorption, in the infrared region, and induced light scattering, which involves inelastic scattering of visible laser light. The particle interactions giving rise to the necessary induced dipole moments and polarizabilities are modelled at long range by multipole expansions; at short range, electron overlap and exchange mechanisms come into play. Information on atomic and molecular interactions and dynamics in dense media on a picosecond timescale may be drawn from the spectra. Collision-induced absorption in the infrared was discovered at the University of Toronto in 1949 by Crawford, Welsh and Locke who studied liquid O and N. Through the 1950s and 1960s, 2 2 experimental elucidation of the phenomenon, particularly in gases, continued and theoretical underpinnings were established. In the late 1960s, the related phenomenon of collision-induced light scattering was first observed in compressed inert gases. In 1978, an 'Enrico Fermi' Summer School was held at Varenna, Italy, under the directorship of J. Van Kranendonk. The lectures, there, reviewed activity from the previous two decades, during which the approach to the subject had not changed greatly. In 1983, a highly successful NATO Advanced Research Workshop was held at Bonas, France, under the directorship of G. Birnbaum. An important outcome of that meeting was the demonstration of the maturity and sophistication of current experimental and theoretical techniques.
Author: G. Birnbaum
Publisher: Springer Science & Business Media
ISBN: 1461325110
Category : Computers
Languages : en
Pages : 784
Get Book Here
Book Description
This book is concerned with recent experimental and theoretical work dealing with phenomena created by the transient dipoles and polarizabilities produced by intermolecular interactions. The for mer produce absorption from the microwave to the optical regions of the spectrum and the latter produce Rayleigh and Raman scattering; such absorption and scattering would be absent without collisions. Static properties, such as dielectric constant, refractive index, and Kerr effect, also exhibit the effects of induced dipoles and polarizabilities. The first observation of an infrared absorption spectrum pro duced by the collisions of molecules which ordinarily do not have an allowed dipole transition was reported in 1949 (Crawford, Welsh, and Locke). The first observation of depolarized Rayleigh spectra due to collisions in atomic gases appeared in 1968 (McTague and Birnbaum). However, it was not until 1977 that the first conference dealing with collision-induced phenomena was organized by J. D. Poll at the University of Guelph. This conference was mainly concerned with studies of collision-induced absorption in gases. Light scat tering received more attention at the second meeting of the colli sion-induced community in 1978, at the E. Fermi Summer School on "Intermolecular Spectroscopy and Dynamical Properties of Dense Sys tems," organized by J. Van Kranendonk. However, the emphasis was still on collision-induced absorption in compressed gases, although some work on liquids, solid H , and related subjects such as ro 2 tational relaxation was included. The third induced phenomena con ference, organized by F.
Author: Hua-Kuang Lee
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 99
Get Book Here
Book Description
In the Big Bang, hydrogen and helium were produced, with very small quantities of deuterium, tritium, and lithium. Due to gravitational attraction, the gases began to congregate. The conversion of gravitational potential energy to kinetic energy raised the temperature. For the gas clouds to continue to contract for form stars, some cooling mechanism was needed. In this thesis, ab initio calculations of collision-induced dipoles are reported, for use in evaluating collision-induced emission as a potential cooling mechanism during the formation of the first stars. In nonequilibrium conditions, molecular hydrogen and atomic hydrogen can coexist, so transient dipoles formed during collisions of molecular hydrogen with either molecular hydrogen or atomic hydrogen may contribute to cooling. The first stars that were formed in the universe are called Population III stars. This thesis includes calculations that are relevant to the observed radiative profiles of very old, very cool white dwarf stars. The detected radiation from the stars is a combination of the radiation from both the core and the stellar atmosphere. Radiation coming from the core may be absorbed by the atmosphere and then reemitted at a lower frequency. The core temperature and the radiative spectrum from the core can be evaluated by fitting the high-energy end of the spectrum with a black-body radiative profile. Often the radiative profile at lower energy does not fit the predicted profile, based on the core temperature. This is attributed to absorption in the stellar atmosphere, due to transient dipoles formed during collisions of hydrogen molecules with hydrogen atoms, helium atoms, or other hydrogen molecules.Due to the harsh conditions that are required for the existence of atomic hydrogen, experimental data collision-induced absorption involving atomic hydrogen is not available from experiment. Also, results at very high temperatures are not available from experiment. The collision-induced dipoles and collision-induced absorption spectra must be determined through computational work. The interest in atomic hydrogen for the astrophysical applications leads to the three research projects that are described in this thesis: 1) the dipole moment of the H2-H system in various configurations, 2) the energy and dipole moment of equilateral/isosceles triangular H3, and 3) the correlation energy and dipole of He-H.This thesis contains high-level ab initio computational results for all three projects, obtained with comparatively large basis sets. The results for H2-H are the best available. The collision-induced dipole has been expressed as a series in the spherical harmonics of the H2 bond vector and the intermolecular vector for various bond lengths and intermolecular separations. The calculated coefficients in this series are reported, and it is shown that the coefficients converge to the known analytical forms at long range. For H3, the energies of the three lowest states are reported as functions of the H-H separation and vertex angle in equilateral and isosceles triangular configurations. The conical intersection is located. For He-H, the calculated correlation energies and the correlation contribution to the dipole are shown to match the known long-range forms very accurately. The leading sp-charge density matrix on H shows the predicted R7 behavior. It appears that larger basis sets are required to show the same behavior at the He center.
Author: J. L. Urbaniak
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Mary Moon
Publisher:
ISBN:
Category : Collision spectroscopy
Languages : en
Pages : 482
Get Book Here
Book Description
Author: Roger Philip Blickensderfer
Publisher:
ISBN:
Category :
Languages : en
Pages : 160
Get Book Here
Book Description
Author: Rand Corporation
Publisher:
ISBN:
Category :
Languages : en
Pages : 35
Get Book Here
Book Description
