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Reaction Sequence Of Iron Sulfide Minerals In Bacteria And Their Use As Biomarkers, Mihály Pósfai, Peter R. Buseck, D. A. Bazylinski, Richard B. Frankel May 1998

Reaction Sequence Of Iron Sulfide Minerals In Bacteria And Their Use As Biomarkers, Mihály Pósfai, Peter R. Buseck, D. A. Bazylinski, Richard B. Frankel

Physics

Some bacteria form intracellular nanometer-scale crystals of greigite (Fe3S4) that cause the bacteria to be oriented in magnetic fields. Transmission electron microscope observations showed that ferrimagnetic greigite in these bacteria forms from nonmagnetic mackinawite (tetragonal FeS) and possibly from cubic FeS. These precursors apparently transform into greigite by rearrangement of iron atoms over a period of days to weeks. Neither pyrrhotite nor pyrite was found. These results have implications for the interpretation of the presence of pyrrhotite and greigite in the martian meteorite ALH84001.

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Observation Of The Radiative Decay D*+→D+Γ, J. Bartelt, Kenneth A. Bloom, Cleo Collaboration May 1998

Observation Of The Radiative Decay D*+→D+Γ, J. Bartelt, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We have observed a signal for the decay D*+→D+γ at a significance of 4 standard deviations. From the measured branching ratio B(D*+→D+γ)/ B(D*+→ D++pi0 = 0.055 ± 0.014 ± 0.010 we find B(D*+→D+γ)= 0.017 ± 0.004 ± 0.003, where the first uncertainty is statistical and the second is systematic. We also report the highest precision determination of the remaining D*+ branching fractions.

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Measuring The Bunch-Length Of An Electron Beam By Utilizing The Laser Heterodyne Technique, Katrina L. Carter May 1998

Measuring The Bunch-Length Of An Electron Beam By Utilizing The Laser Heterodyne Technique, Katrina L. Carter

Electronic Dissertations and Theses

The focus of this project was to develop an apparatus that would aid in measuring the bunch-length of an electron beam at the interaction point of the Stanford Linear Collider (SLC) by utilizing the laser heterodyne technique. This technique involves the superposition of two laser pulses of slightly different frequencies. As a result, a traveling fringe pattern is created, and a bunch-to-bunch variation of the Compton rate would be introduced. The magnitude of this variation depends on the best wavelength and on Fourier transform of the longitudinal bunch distribution. The laser heterodyne technique is implemented by the addition of a …

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The Spin Polarized Band Structure Of Strained Thin Films Of Gadolinium, C. Waldfried, Elio Vescovo, Peter A. Dowben May 1998

The Spin Polarized Band Structure Of Strained Thin Films Of Gadolinium, C. Waldfried, Elio Vescovo, Peter A. Dowben

Peter Dowben Publications

The magnetic properties of strained thin films of gadolinium are characterized by a wave vector and thickness dependence of the exchange splitting. The spin-resolved band structure has been mapped by spin polarized photoemission, and provides considerable insight into the relationship between magnetism of local moment systems, and band structure.

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Nobel Prize Winners In Physics From 1901 To 1990: Simple Statistics For Physics Teachers, Weijia Zhang, Robert Fuller May 1998

Nobel Prize Winners In Physics From 1901 To 1990: Simple Statistics For Physics Teachers, Weijia Zhang, Robert Fuller

Robert G. Fuller Publications

A demographic database for the 139 Nobel prize winners in physics from 1901 to 1990 has been created from a variety of sources. The results of our statistical study are discussed in the light of the implications for physics teaching.

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The Growth Of Strained Thin Films Of Gadolinium, C. Waldfried, O. Zeybek, T. Bertrams, S.C. Barrett, Peter A. Dowben May 1998

The Growth Of Strained Thin Films Of Gadolinium, C. Waldfried, O. Zeybek, T. Bertrams, S.C. Barrett, Peter A. Dowben

Peter Dowben Publications

The growth of strained thin films of gadolinium has been investigated with low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM) and compared to the film growth of unstrained gadolinium. Strained thin films of gadolinium are distinct from the unstrained films by a substrate induced preferential domain growth direction, which is also reflected in the electronic structure.

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Invariant Representations Of Finite Rotation Matrices And Some Applications, N. L. Manakov, A. V. Meremianin, Anthony F. Starace May 1998

Invariant Representations Of Finite Rotation Matrices And Some Applications, N. L. Manakov, A. V. Meremianin, Anthony F. Starace

Anthony F. Starace Publications

Standard representations of finite rotation matrices (FRM) are defined by expressions that are wedded to two particular coordinate frames such as, e.g., are involved in the definition of Euler angles. We present here representations for the FRM in invariant tensor forms comprised of vectors defined in a space-fixed coordinate frame K. Three explicit expressions for a FRM are presented: First, in terms of tensor products of the spherical or Cartesian basis vectors of frame K, second in a differential form containing the tensor products of gradient operators, and, third, as the superposition of so-called “minimal” bipolar harmonics depending …

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Thermoconvective Instability Of Paramagnetic Fluids In A Nonuniform Magnetic Field, J. Huang, D. D. Gray, Boyd F. Edwards May 1998

Thermoconvective Instability Of Paramagnetic Fluids In A Nonuniform Magnetic Field, J. Huang, D. D. Gray, Boyd F. Edwards

All Physics Faculty Publications

The effect of a static, nonuniform magnetic field on a laterally unbounded nonconducting paramagnetic fluid layer heated from below or above is studied using a linear stability analysis of the Navier-Stokes equations supplemented by Maxwell’s equations and the appropriate magnetic body force. Buoyancy-driven convection can be controlled by subjecting the layer to a nonuniform magnetic field. Theoretical predictions agree with experimental observations.

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All-Sky Measurements Of The Mesospheric "Frontal Events" From Bear Lake Observatory, Utah, Seon-Hee Seo May 1998

All-Sky Measurements Of The Mesospheric "Frontal Events" From Bear Lake Observatory, Utah, Seon-Hee Seo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies of internal gravity waves in the earth's upper atmosphere are of considerable interest. These waves play a very important role in the dynamics of the mesosphere and lower thermosphere (ML T) region where they can transfer large amounts of energy and momentum from the lower atmosphere via wave saturation and dissipation. In particular, small-scale short-period ( < 1 hour) waves of the type regularly recorded by all-sky nightglow imagers operated by Utah State University (USU) are known to be very important contributors. In this thesis attention is focused on a subset of small-scale wave phenomena recently discovered using such image data, the so called "frontal events." Frontal events have distinguishable characteristics from usual short-period ( < 1 hour) gravity waves. The principal characteristics are a well defined leading "front, " which exhibits a sharp change in intensity followed by a coherent wave trail (often extending from horizon to horizon) and relatively high phase speeds ( > 50ms-1) Another unusual characteristic of "frontal events" is an apparent reversal in contrast of the wave structures as imaged in the hydroxyl (OH) emission (peak altitude - 87 km) when compared with the oxygen (OJ) "green line" (557.7 nm) emission (peak …

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Deep Centers In N-Gan Grown By Reactive Molecular Beam Epitaxy, Z-Q. Fang, David C. Look, W. Kim, Z. Fan, A. Botchkarev, H. Morkoç May 1998

Deep Centers In N-Gan Grown By Reactive Molecular Beam Epitaxy, Z-Q. Fang, David C. Look, W. Kim, Z. Fan, A. Botchkarev, H. Morkoç

Physics Faculty Publications

Deep centers in Si-doped n-GaN layers grown by reactive molecular beam epitaxy have been studied by deep-level transient spectroscopy as a function of growth conditions. Si-doped GaN samples grown on a Si-doped n+-GaN contact layer at 800 °C show a dominant trap C1 with activation energy ET = 0.44 eV and capture cross-section σT = 1.3×10−15 cm−2, while samples grown at 750 °C on an undoped semi-insulating GaN buffer show prominent traps D1 and E1, with ET = 0.20 eV and σT = 8.4×10−17 cm …

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Neutral-Donor-Bound-Exciton Complexes In Zno Crystals, D. C. Reynolds, David C. Look, B. Jogai, C. W. Litton, T. C. Collins, W. C. Harsch, G. Cantwell May 1998

Neutral-Donor-Bound-Exciton Complexes In Zno Crystals, D. C. Reynolds, David C. Look, B. Jogai, C. W. Litton, T. C. Collins, W. C. Harsch, G. Cantwell

Physics Faculty Publications

Neutral-donor–bound-exciton transitions have been observed in ZnO. The isolated neutral donors are made up of defect pair complexes. The neutral-donor nature of these pair complexes was determined from magneticfield measurements and from two-electron transitions. Excited states of the neutral-donor bound excitons were observed in the form of rotator states analogous to rotational states of the H2 molecule.

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Discrete-To-Continuum Simulation Approach To Polymer Chain Systems: Subdiffusion, Segregation, And Chain Folding, Grace M. Foo, Ras B. Pandey May 1998

Discrete-To-Continuum Simulation Approach To Polymer Chain Systems: Subdiffusion, Segregation, And Chain Folding, Grace M. Foo, Ras B. Pandey

Faculty Publications

A discrete-to-continuum approach is introduced to study the static and dynamic properties of polymer chain systems with a bead-spring chain model in two dimensions. A finitely extensible nonlinear elastic potential is used for the bond between the consecutive beads with the Lennard-Jones (LJ) potential with smaller (Rc=21/6σ=0.95) and larger (Rc=2.5σ=2.1) values of the upper cutoff for the nonbonding interaction among the neighboring beads. We find that chains segregate at temperature T =1.0 with Rc=2.1 and remain desegregated with Rc=0.95. At low temperature (T=0.2), chains become folded, …

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The New Aleph Silicon Vertex Detector, D. Creanza, Manoj Thulasidas May 1998

The New Aleph Silicon Vertex Detector, D. Creanza, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The ALEPH collaboration, in view of the importance of effective vertex detection for the Higgs boson search at LEP 2, decided to upgrade the previous vertex detector. Main changes were an increased length (+/- 20 cm), a higher granularity for r phi view (50 mu m), a new preamplifier (MX7 rad hard chip), a polymide (upilex) fan-out on z side to carry the signals from the strips to the front-end electronics outside the fiducial region reducing consequently the passive material in the central region by a factor of two. The detector, the running experience and its performance will be described. …

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High Mobility Algan/Gan Heterostructures Grown By Gas-Source Molecular Beam Epitaxy, L. K. Li, J. Alperin, W. I. Wang, David C. Look, Donald C. Reynolds May 1998

High Mobility Algan/Gan Heterostructures Grown By Gas-Source Molecular Beam Epitaxy, L. K. Li, J. Alperin, W. I. Wang, David C. Look, Donald C. Reynolds

Physics Faculty Publications

We report on the growth of high electron mobility AlGaN/GaN heterostructures on sapphire substrates by gas-source molecular beam epitaxy (GSMBE) using ammonia as the nitrogen source. Improvements in structural, electrical, and optical properties of GaN and AlGaN layers have been made to achieve this goal. For the growth of AlGaN layers, the reflection high-energy electron diffraction revealed a twofold surface reconstruction, indicative of atomic smoothness of the film surface. High mobility two-dimensional electron gas has been achieved in both unintentionally doped (by piezoelectric effect induced by lattice mismatch strain) and modulation doped AlGaN/GaN heterostructures. The modulation-doped n+-Al0.2Ga …

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Known Source Detection Predictions For Higher Order Correlators, Lisa A. Pflug, George E. Ioup, Juliette W. Ioup May 1998

Known Source Detection Predictions For Higher Order Correlators, Lisa A. Pflug, George E. Ioup, Juliette W. Ioup

Physics Faculty Publications

The problem addressed in this paper is whether higher order correlation detectors can perform better in white noise than the cross correlation detector for the detection of a known transient source signal, if additional receiver information is included in the higher order correlations. While the cross correlation is the optimal linear detector for white noise, additional receiver information in the higher order correlations makes them nonlinear. In this paper, formulas that predict the performance of higher order correlation detectors of energy signals are derived for a known source signal. Given the first through fourth order signal moments and the noise …

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Confocal Microscopy: A Powerful Tool For Biological Research, Amit Singh, K. P. Gopinathan May 1998

Confocal Microscopy: A Powerful Tool For Biological Research, Amit Singh, K. P. Gopinathan

Biology Faculty Publications

Conventional light microscopy allows the observation of living as well as fixed cells and tissues to generate two-dimensional images. The out-of-focus information often obscures the ultrastructural details, especially in thick specimens with overlapping structures. The earliest available light microscopy visualized the objects in hydrated state in two-dimensions during their temporal development. The emergence of electron microscopy (EM) provided superb resolution of ultrastructural details, but it was applicable only for objects in the dehydrated state and thereby potentially introducing handling artifacts. The usefulness of optical methods, however, has been limited by the poor depth discrimination. Often, the fluorescence and reflectance images …

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Particle Concentration Characterization For Jet Engine Emissions Under Cruise Conditions, Jonathan D. Paladino, Philip D. Whitefield, Donald E. Hagen, Alfred R. Hopkins, Max B. Trueblood May 1998

Particle Concentration Characterization For Jet Engine Emissions Under Cruise Conditions, Jonathan D. Paladino, Philip D. Whitefield, Donald E. Hagen, Alfred R. Hopkins, Max B. Trueblood

Chemistry Faculty Research & Creative Works

Airborne particle measurements during NASA project SUCCESS have shown that particle concentration profiles serve as good indicators of aircraft exhaust plume encounters. During exhaust plume penetrations there is a strong anticorrelation between the ratio of nonvolatile/total particulates and Nitrogen Oxide (NO) concentrations. an increase in fuel sulfur content was found to increase the total particle emission index, while the nonvolatile emission index remained unchanged. the EI's increased by a factor of 2.6 as the fuel sulfur increased from 70 - 700 ppm. the large particle size distribution (200-400 nm) was seen as a good long term indicator of an aircraft …

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Sources And Chemistry Of Noₓ In The Upper Troposphere Over The United States, Lyatt Jaegle, Daniel J. Jacob, Yuhua Wang, Andrew J. Weinheimer, Brian A. Ridley, Teresa L. Campos, Glen W. Sachse, Donald E. Hagen May 1998

Sources And Chemistry Of Noₓ In The Upper Troposphere Over The United States, Lyatt Jaegle, Daniel J. Jacob, Yuhua Wang, Andrew J. Weinheimer, Brian A. Ridley, Teresa L. Campos, Glen W. Sachse, Donald E. Hagen

Physics Faculty Research & Creative Works

The origin of NOx in the upper troposphere over the central United States is examined using aircraft observations obtained during the SUCCESS campaign in April–May of 1996. Correlations between NOy (sum of NOx and its oxidation products) and CO at 8–12 km altitude indicate that NOx originates primarily from convective transport of polluted boundary layer air. Lightning and aircraft emissions appear to be only minor sources of NOx. Chemical steady state model calculations constrained by local observations of NO underestimate the measured NOx/NOy concentration ratio at 8–12 km altitude by a …

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Particulate Sizing And Emission Indices For A Jet Engine Exhaust Sampled At Cruise, Donald E. Hagen, Philip D. Whitefield, Jonathan D. Paladino, Max B. Trueblood May 1998

Particulate Sizing And Emission Indices For A Jet Engine Exhaust Sampled At Cruise, Donald E. Hagen, Philip D. Whitefield, Jonathan D. Paladino, Max B. Trueblood

Physics Faculty Research & Creative Works

Particle size and emission indices measurements for jet engines, primarily the Rolls Royce RB211 engines on a NASA 757 aircraft are reported. These data were used to estimate the fraction of fuel sulfur that was converted to particulates. These measurements were made in-situ with the sampling aircraft several kilometers behind the source. Some complimentary ground measurements on the same source aircraft and engines are also reported. Significant differences are seen between the ground observations and the in-situ observations, indicating that plume processes are changing the aerosol's characteristics.

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Field-Induced Transverse Spin Ordering In Febr2, O. Petracie, Christian Binek, Wolfgang Kleemann, U. Neuhausen, H. Lueken May 1998

Field-Induced Transverse Spin Ordering In Febr2, O. Petracie, Christian Binek, Wolfgang Kleemann, U. Neuhausen, H. Lueken

Christian Binek Publications

Weak first-order phase transitions from axial to oblique spin ordering in FeBr2 are evidenced by superconducting quantum interference device magnetometry in axial fields H1(T) above the multicritical point, Hm=2.4 MA/m, Tm=4.6 K, and below the antiferro-to-paramagnetic phase line, Hc (T), in agreement with recent specific-heat data [H. Aruga Katori, K. Katsumata, and M. Katori, Phys. Rev. B 54, R9620 (1996)]. The ordering of the in-plane moments is probably due to nondiagonal coupling to the longitudinal ones, both of which increase discontinuously at H1 (T) only under …

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New Limits For Neutrinoless Tau Decays, D. W. Bliss, Kenneth A. Bloom, Cleo Collaboration May 1998

New Limits For Neutrinoless Tau Decays, D. W. Bliss, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using 4.79 fb-1 of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits are either more stringent than those set previously or represent the first attempt to find these decays.

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Search For Color-Suppressed B Hadronic Decay Processes At The Υ(4S) Resonance, B. Nemati, Kenneth A. Bloom, Cleo Collaboration May 1998

Search For Color-Suppressed B Hadronic Decay Processes At The Υ(4S) Resonance, B. Nemati, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

Using 3.1 fb-1 of data accumulated at the Υ(4S) by the CLEO-II detector, corresponding to 3.3×106 BB̅ pairs, we have searched for the color-suppressed B hadronic decay processes B0→D0 (D*0)X0, where X0 is a light neutral meson π0, ρ0, η, η′ or ω. The D*0 mesons are reconstructed in D*0→D0π0 and the D0 mesons in D0→K-π+, K-π+π0 and K …

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Two-Body B Meson Decays To Η And Η′: Observation Of B→Η′K, B. H. Behrens, Kenneth A. Bloom, Cleo Collaboration Apr 1998

Two-Body B Meson Decays To Η And Η′: Observation Of B→Η′K, B. H. Behrens, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

In a sample of 6.6 X 106 produced B mesons we have observed decays B → η′K, with branching fractions Ɓ(B+ → η′K) = 6.5-1.4+1.5± 0.9) X 10-5 and Ɓ(B0 → η′K0) = 4.7-2.0+2.7 ± 0.9) X 10-5. We have searched with comparable sensitivity for 17 related decays to final states containing an η or η′ meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the B → η′K signal.

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X-Ray Spectroscopic Mapping Of Three Unusual Active Galaxies (Ngc 4258, Ngc 1097, And Ngc 1068), Jeremy Kotter '98 Apr 1998

X-Ray Spectroscopic Mapping Of Three Unusual Active Galaxies (Ngc 4258, Ngc 1097, And Ngc 1068), Jeremy Kotter '98

Honors Projects

One enigmatic class of objects whose structures are interesting and only recently explored are active galactic nuclei (AGN). These are galaxies in which massive black holes sit at the center and accrete matter. The term "active" refers to energetic processes which are not directly attributable to stars and which occur in the innermost portions of galaxies. Astrophysicists have developed general descriptions of AGN, but details about these objects remain incomplete. Notably, the thermal and ionization structures of AGN accretion disks and the geometries of the circum-source clouds which surround the black hole and comprise an important portion of the energy …

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Measurement Of B(D0 → K-Π+) Using Partial Reconstruction Of B̅ → D*+Xℓ- Ν̅, M. Artuso, Kenneth A. Bloom, Cleo Collaboration Apr 1998

Measurement Of B(D0 → K-Π+) Using Partial Reconstruction Of B̅ → D*+Xℓ- Ν̅, M. Artuso, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We present a measurement of the absolute branching fraction for D0 → K-π+ using the reconstruction of the decay chain B̅ → D*+Xℓ- ν̅ where only the lepton and the low-momentum pion from the D*+ are detected. With data collected by the CLEO II detector at the Cornell Electron Storage Ring, we have determined Ɓ(D0 → K-π+)= [3.81 ± 0.15(stat) ± 0.16(syst)]%.

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Evidence For A Scalar Kappa(900) Resonance In Pi-K Scattering, Joseph Schechter, Deirdre Black, Amir H. Fariborz, Francesco Sannino Apr 1998

Evidence For A Scalar Kappa(900) Resonance In Pi-K Scattering, Joseph Schechter, Deirdre Black, Amir H. Fariborz, Francesco Sannino

Physics - All Scholarship

Motivated by the 1/N_c\ expansion, we study a simple model in which the pi-K scattering amplitude is the sum of a current-algebra contact term and resonance pole exchanges. This phenomenological model is crossing symmetric and, when a putative light strange scalar meson, kappa, is included, satisfies the unitarity bounds to well above 1 GeV. The model also features chiral dynamics, vector meson dominance and appropriate interference between the established scalar K*(1430) resonance and its predicted background. We briefly discuss the physical significance of the results and directions for further work.

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Dynamic And Chemical Aspects Of The Mesospheric Na ‘Wall’ Event On 9 October 1993 During The Aloha Campaign, G. R. Swenson, J. Qian, J. M.C. Plane, P. J. Espy, Michael J. Taylor, D. N. Turnbull, R. P. Lowe Apr 1998

Dynamic And Chemical Aspects Of The Mesospheric Na ‘Wall’ Event On 9 October 1993 During The Aloha Campaign, G. R. Swenson, J. Qian, J. M.C. Plane, P. J. Espy, Michael J. Taylor, D. N. Turnbull, R. P. Lowe

All Physics Faculty Publications

On October 9, 1993, observations were made from the National Center for Atmospheric Research Electra aircraft during a flight from Maui, Hawaii, toward a low-pressure system NW of the island, a flight of 7 hours in total. The leading edge (wall) of a bright airglow layer was observed 900 km NW of Maui at 0815 UT, which was traveling at 75 m s−1 toward the SE, reaching Haleakala, Maui, about 3.25 hours later [see Swenson and Espy, 1995]. An intriguing feature associated with the event was the large increase in the mesospheric Na column density at the wall (∼180%). The …

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Application Of Tomographic Inversion In Studying Airglow In The Mesopause Region, T. Nygren, Michael J. Taylor, M. S. Lehtinen, M. Markkanen Apr 1998

Application Of Tomographic Inversion In Studying Airglow In The Mesopause Region, T. Nygren, Michael J. Taylor, M. S. Lehtinen, M. Markkanen

All Physics Faculty Publications

It is pointed out that observations of periodic nightglow structures give excellent information on atmospheric gravity waves in the mesosphere and lower thermosphere. The periods, the horizontal wavelengths and the phase speeds of the waves can be determined from airglow images and, using several cameras, the approximate altitude of the luminous layer can also be determined by triangulation. In this paper the possibility of applying tomographic methods for reconstructing the airglow structures is investigated using numerical simulations. A ground-based chain of cameras is assumed, two-dimensional airglow models in the vertical plane above the chain are constructed, and simulated data are …

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Scaling Studies Of Spheromak Formation And Equilibrium, Cameron G. R. Geddes , '97, Thomas W. Kornack , '98, Michael R. Brown Apr 1998

Scaling Studies Of Spheromak Formation And Equilibrium, Cameron G. R. Geddes , '97, Thomas W. Kornack , '98, Michael R. Brown

Physics & Astronomy Faculty Works

Formation and equilibrium studies have been performed on the Swarthmore Spheromak Experiment (SSX). Spheromaks are formed with a magnetized coaxial plasma gun and equilibrium is established in both small (d(small)=0.16 m) and large (d(large)=3d(small)=0.50 m) copper flux conservers. Using magnetic probe arrays it has been verified that spheromak formation is governed solely by gun physics (in particular the ratio of gun current to flux, mu(0)I(gun)/Phi(gun)) and is independent of the flux conserver dimensions. It has also been verified that equilibrium is well described by the force free condition del xB=lambda B (lambda=constant), particularly early in decay. Departures from the force-free …

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Nonlocal Theory Of Dissociative Electron Attachment To H2 And Hf Molecules, Gordon A. Gallup, Y. [Yuanguang] Xu, Ilya I. Fabrikant Apr 1998

Nonlocal Theory Of Dissociative Electron Attachment To H2 And Hf Molecules, Gordon A. Gallup, Y. [Yuanguang] Xu, Ilya I. Fabrikant

Gordon Gallup Publications

We develop a method for calculation of dissociative electron attachment cross sections based on the Fano- Feshbach projection-operator approach. The coupling between the diabatic state and electron continuum is calculated with the inclusion of orthogonality scattering and long-range electron-molecule interaction. The dynamics of nuclear motion in the non-local complex potential is treated by semiclassical theory. We apply the theory to the calculation of dissociative attachment to the H2 and HF molecules. Our results for attachment to ground-state hydrogen molecules and the near-threshold vibrational enhancement of H2 are essentially the same as previous non-local results. However, the shape of …

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