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Tunable far infrared laser spectroscopy of van der Waals bonds: Ar-NH sub 3

Description: Hyperfine resolved vibration-rotation-tunneling spectra of Ar--NH{sub 3} and (NH{sub 3}){sub 2}, generated in a planar supersonic jet, have been measured with the Berkeley tunable far infrared laser spectrometer. Among the seven rotationally assigned bands, one band belongs to Ar--NH{sub 3}, and the other six belong to (NH{sub 3}){sub 2}. To facilitate the intermolecular vibrational assignment for Ar--NH{sub 3}, a dynamics study aided by a permutation-inversion group theoretical treatment is pe… more
Date: November 1, 1989
Creator: Gwo, Dz-Hung (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Chemistry)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Condensed molecular beam as gas target for antiprotons in the SPS

Description: With condensed molecular beams of hydrogen as described in literature, very well defined high local gas densities can be produced, which for antiproton beams of 5 x 10/sup 11/ give luminosities between 10/sup 30/ and 10/sup 31/ cm/sup -2/ sec/sup -1/, two orders of magnitude higher than the luminosity estimates for p-anti p physics in the ISR (10/sup 28/ to 10/sup 29/) and one order of magnitude higher than the luminosity for p-anti p physics in the SPS. After some minor modifications, the same… more
Date: February 14, 1978
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Threshold photodetachment spectroscopy of negative ions

Description: This thesis is concerned with the development and application of high resolution threshold photodetachment spectroscopy of negative ions. Chapter I deals with the principles of our photodetachment technique, and in chapter II a detailed description of the apparatus is presented. The threshold photodetachment spectra of I{sup {minus}}, and SH{sup {minus}}, presented in the last sections of chapter II, indicated that a resolution of 3 cm{sup {minus}1} can be achieved using our technique. In chapt… more
Date: December 1, 1991
Creator: Kitsopoulos, T. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Photodissociation Processes in Molecular Beams

Description: A description is presented of a study of the photodissociation dynamics of molecules in a molecular beam. Photo-fragmentation translational spectroscopy has been utilized to observe the photodissociation dynamics of ozone. Using a supersonic molecular beam and a 10 nanosecond pulsed laser at lambda = 266 nm, the velocities of the fragment products are measured by the method of time of flight. The resolution of the time of flight spectrum of ozone is sufficiently high that the electronic and vib… more
Date: May 1, 1979
Creator: Carlson, L. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Reactions of carbon atoms using crossed pulsed molecular beams

Description: In the second year of the current funding period, we continued the study of the following reactions: C({sup 1}D) + H{sub 2} {yields} CH(X{sup 2}{Omicron}) + H, {Delta}H = {minus}6.0 kcal.mol{sup {minus}1}; C({sup 1}D) + HCl {yields} CH(X{sup 2}{Omicron}) + Cl, {Delta}H = 7.0 kcal.mol{sup {minus}1}; and C({sup 1}D) + HCl {yields} CCl(X{sup 2}{Omicron}) + H, {Delta}H = {minus}5.8 kcal.mol{sup {minus}1}. In particular, we concentrated on three issues: the use of two-photon photolysis of C{sub 3}O{… more
Date: April 1, 1990
Creator: Reisler, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Crossed Laser and Molecular Beam Study of Multiphoton Dissociation of C/sub 2/F/sub 5/Cl

Description: Rate constants for the photodissociation of C/sub 2/F/sub 5/Cl as well as the yield of C/sub 2/F/sub 4//sup +/ were measured. The dynamics of the two dissociation channels was studied by measuring the angular and velocity distributions of the products. 2 references. (JFP)
Date: September 1, 1978
Creator: Krajnovich, D.J.; Giardini-Guidoni, A.; Sudboe, A.S.; Schulz, P.A.; Shen, Y.R. & Lee, Y.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electric-dipole moment of CaF by molecular-beam, laser-rf, double-resonance study of Stark splittings

Description: The electronic structure of diatomic molecules is much more complex for open-shell sytems (radicals) than for the normal closed-shell systems, and the development of an adequate theoretical understanding will require a substantial upgrading of experimental knowledge in both quality and quantity. The alkaline-earth monohalide family of radicals, with only a single electron outside closed-shell cores, would appear to be a logical starting point for such studies, and there has been a great increas… more
Date: January 1, 1984
Creator: Childs, W. J.; Goodman, L. S.; Nielsen, U. & Pfeufer, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Chemical Sciences Division annual report, 1990

Description: This report contains sections on the following topics: photochemistry of materials in the stratosphere, energy transfer and structural studies of molecules on surfaces, crossed molecular beams, molecular interactions, theory of atomic and molecular collision processes, selective photochemistry, photodissociation of free radicals, physical chemistry with emphasis on thermodynamic properties, chemical physics at the high photon energies, high-energy atomic physics, atomic physics, high-energy oxi… more
Date: August 1, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Crossed molecular beam studies of unimolecular reaction dynamics. [Angular and velocity distributions]

Description: The study of seven radical-molecule reactions using the crossed molecular beam technique with supersonic nozzle beams is reported. Product angular and velocity distributions were obtained and compared with statistical calculations in order to identify dynamical features of the reactions. In the reaction of chlorine and fluorine atoms with vinyl bromide, the product energy distributions are found to deviate from predictions of the statistical model. A similar effect is observed in the reaction o… more
Date: April 1, 1979
Creator: Buss, R.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Active sites for hydrocarbon catalysis on metal surfaces

Description: There is a great deal of experimental evidence associating selective bond breaking ability with low coordination number surface sites on transition metal surfaces. Atomic steps break H-H and C-H bonds efficiently while kinks in the steps are required for additional C-C and C=O bond scissions. The blockage of some of the ''active sites'' yields the reaction selectivity commonly observed as a result of alloying or upon introduction of certain promoters. Another important parameter in controlling … more
Date: October 18, 1977
Creator: Somorjai, G.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The evaporative vector: Homogeneous systems

Description: Molecular beams of van der Waals molecules are the subject of much current research. Among the methods used to form these beams, three-sputtering, laser ablation, and the sonic nozzle expansion of neat gases - yield what are now recognized to be ''warm clusters.'' They contain enough internal energy to undergo a number of first-order processes, in particular that of evaporation. Because of this evaporation and its attendant cooling, the properties of such clusters are time-dependent. The states… more
Date: May 1, 1987
Creator: Klots, C.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Preliminary Evaluation of a Modified Mueller--Hortig Geometry Negative Ion Source Using a Negative Ion Source Test Facility

Description: A negative sputter-type ion source of the Mueller-Hortig geometry is described which utilizes a positive surface ionization source. Among the ion beams which have been produced are: Al-0.2 $mu$A; All0$sup -$-3 $mu$A; Au$sup -$- 6 $mu$A; C$sup -$-25 $mu$A; C$sub 2$$sup -$-20$mu$A; Cl$sup -$-100 $mu$A; Cu$sup - $-0.5 $mu$A; CuO$sup -$-0.8 $mu$A; F$sup -$-40 $mu$A; I$sup -$-26 $mu$A; 0$sup -$- 30 $mu$A; Pt$sup -$-3 $mu$A; S$sup -$-44 $mu$A; TaO$sub 2$$sup -$-2 $mu$A. The yields of Cl$sup -$, F$sup… more
Date: January 1, 1975
Creator: Alton, G. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Experimental Chemical Kinetics: A Study of Chemical Reactions by Means of Molecular Beam Techniques. Progress Report, October 1975--October 1976

Description: The exchange of translational with internal energy ..delta..E in collisions of CsI with Ar and Xe is studied at initial kinetic energies in the thermal range. Differential cross sections are integrated over scattering angles to get total cross sections for various ..delta..E. There is evidence that a short-lived complex is formed at low energies. Beams of electrons can influence the motion of neutral atoms and molecules by concentrating them near the electronic beam. This effect, which has been… more
Date: October 1, 1976
Creator: Greene, E. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Photoionization studies with molecular beams

Description: A molecular beam photoionization apparatus which combines the advantages of both the molecular beam method with photoionization mass spectrometry has been designed and constructed for carrying out some unique photoionization experiments. Rotational cooling during the supersonic expansion has resulted in high resolution photoionization efficiency curves for NO, ICl, C/sub 2/H/sub 2/ and CH/sub 3/I. The analysis of these spectra has yielded ionization potentials for these molecules to an accuracy… more
Date: September 1, 1976
Creator: Ng, C. Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Reactive and nonreactive scattering of modulated molecular beams from well characterized platinum single crystal surfaces. [Mechanism, rainbow scattering, angular distribution]

Description: Reactive and nonreactive gas-surface interactions were studied by modulated molecular beam mass spectrometry on Pt(111) and stepped Pt(111) surfaces under ultra-high vacuum conditions. The angular distribution of helium atoms scattered from the stepped Pt(553) surface was measured as a function of the angle of incidence (polar, theta, and azimuthal, Phi). Rainbow scattering was observed indicating that the ordered array of steps and terraces exhibits a strongly periodic surface potential. In co… more
Date: December 1, 1978
Creator: Gale, Rebecca Johnson
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Crossed beam studies of full and half collisions. [F + H/sub 2/(D/sub 2/)]

Description: Results of two experiments performed on a new very high resolution crossed molecular beams apparatus are discussed. The first experiment, photofragmentation of methyl iodide, is deconvoluted to yield vibrational state distributions for the recoiling methyl fragment. These distributions are then analyzed in terms of half-collision models and Franck-Condon factors. The second experiment, a full-collision example, is the reaction of F atoms with H/sub 2/ and D/sub 2/. Laboratory angular and veloci… more
Date: November 1, 1979
Creator: Sparks, R. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Studies of gas phase reactions of uranium with selected oxidizers and fluoromethanes

Description: A crossed molecular beam study was made of the reactions of U with inorganic oxidizers (O/sub 2/, NO, SO/sub 2/, N/sub 2/O, CO/sub 2/), water, alcohols, acetone, and halogenated methanes. Results show that U in the gas phase behaves very much like most other heavy metals, and may be called a heavy Ba or Sn atom. 8 figures. (DLC)
Date: April 6, 1979
Creator: Lang, N. C. & Stern, R. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effects of Reagent Translational and Vibrational Energy on the Dynamics of Endothermic Reactions

Description: The endothermic reactions Br + CH/sub 3/I ..-->.. CH/sub 3/ + IBr (..delta..H/sub 0//sup 0/ = 13 kcal/mole) and Br + CF/sub 3/I ..-->.. CF/sub 3/ + IBr (..delta..H/sub 0//sup 0/ = 11 kcal/mole) have been studied by the crossed molecular beams method. Detailed center-of-mass contour maps of the IBr product flux as a function of recoil velocity and scattering angle are derived. For both systems it is found that the IBr product is sharply backward scattered with respect to the incident Br dirction… more
Date: July 1, 1981
Creator: Krajnovich, D.; Zhang, Z.; Huisken, F.; Shen, Y.R. & Lee, Y.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reactions of carbon atoms using crossed pulsed molecular beams

Description: The development of efficient carbon atom sources was carried out concurrently with studying reactions 1--3, and we already have intriguing results concerning these reactions, even though the development phase is still in progress. Our goals are to study reactions of carbon atoms with hydrogen, hydrogen chloride, and nitrous oxide include correlations between the energy distributions of the fragments, branching ratios, and kinetic energy dependences. These studies will provide prototypical examp… more
Date: April 1, 1989
Creator: Reisler, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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