| Vibrational Relaxation and Collision-Induced Dissociation of Xenon Fluoride by Neon |
01 MAR 89 |
35 pages |
| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB
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 | Rate coefficients were calculated for vibrational relaxation and collision induced dissociation of ground state xenon fluoride in neon at temperatures between 300 and 1000 K for each of nine vibrational levels. These coefficients were calculated using a pairwise additive potential energy surface, which consists, of a Morse function for the XeF interaction and Lennard-Jones functions for the NeXe and NeF interactions. Rate coefficients are provided for temperature and v-dependences. The ... |
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| Theoretical Calculations of XeF Ground State Kinetics |
01 MAR 88 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB
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 | State-to-state rate coefficients were calculated for collision- induced vibrational-to-translational (V-T) and rotational-to-translational (R-T) relaxation, and for dissociation processes that occur when XeF(v,J) molecules collide with He atoms. Three-dimensional classical trajectories of the collision dynamics of these processes were calculated by means of a pairwise additive potential energy surface, which consists of a Morse function for the XeF interaction and Lennard-Jones functions for the HeXe and HeF interactions. On the basis ... |
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| Rotational Energy Transfer in HF |
16 MAY 1983 |
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| Authors:
Roger L. Wilkins; Munson A. Kwok; AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB
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| A rotational nonequilibrium model has been developed to simulate the infrared double-resonance experimental technique designed to study rotational relaxation of HF gas in the v = 1 and higher vibrational states. State-to-state rate coefficients for this rotation-to-translation relaxation model have been obtained from a surprisal analysis and are found to scale as an inverse power of the rotational energy transferred. Phenomenological rates for the rotational energy transfer in the v ... |
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| Temperature Dependence of Vibrational Relaxation from the Upper Vibrational Levels of HF and DF. |
29 AUG 1980 |
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| Authors:
Roger L. Wilkins; Munson A. Kwok; AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB
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| Room temperature quenching rate coefficients for relaxation from the upper vibrational levels of HF and DF have been successfully duplicated with good agreement with available experimental data. This agreement was obtained with the use of a rotational nonequilibrium model and rate coefficients computed by Wilkins. The key processes are V to R and R to V mechanisms, which give the problem a multiple-channel nature. The model provided temperature-dependent quenching rate ... |
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| Temperature Dependence of HE(v sub 1 = 1) + HF(v sub 2 = 0) Vibrational Relaxation. |
15 AUG 1978 |
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| Authors:
Roger L. Wilkins; Munson A. Kwok; AEROSPACE CORP EL SEGUNDO CALIF IVAN A GETTING LABS
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| A kinetics model of infrared laser-induced fluorescence experiments has been used to simulate the experimental quenching rate coefficients reported between 300 and 4000 K for the vibrational relaxation of HF(v 1 = 1) by HF. This rotational nonequilibrium model is based on the predicted energy-transfer mechanisms in hydrogen fluoride systems reported in a trajectory study by Wilkins. This model includes v yields R, R yields v, R yields (R', T'), ... |
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| Vibrational Relaxation in the HF-DF and DF-HF Systems. |
08 JUN 1978 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF AEROPHYSICS LAB
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| Mechanisms of Energy Transfer in Deuterium Fluoride Systems. |
13 APR 1978 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF IVAN A GETTING LABS
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| A three-dimensional trajectory study has been employed to determine temperature-dependent rate coefficients for the important energy-transfer and deactivation processes that occur in DF(v1) + DF(v2) collisions. From this study, it was predicted that the v to v energy-transfer processes occur by means of delta v = + or - 1 transitions and that the rate coefficients for the v to v processes DF(v1 = 1) + DF(v2) to DF(v1' = ... |
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| Mechanisms of Energy Transfer in Hydrogen Fluoride Systems. |
23 SEP 1977 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF AEROPHYSICS LAB
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| Rate coefficients are calculated for the energy-transfer processes that occur when HF(v1,J1) molecules collide with HF(v2,J2) molecules. Three-dimensional classical trajectories of the collision dynamics of these energy-transfer processes were calculated by means of a potential energy surface, which consists of a London-Eyring-Polanyi-Sato (LEPS) potential function for the short-range interactions and a partial-point-charge, dipole-dipole function for the long-range interactions. This energy surface was used to predict an equilibrium geometry of the ... |
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| Vibration-Rotation Bands of HF and DF. |
23 SEP 1977 |
125 pages |
| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF AEROPHYSICS LAB
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| Calculations have been made for HF of the rotational lines for both the P- and R-branches in 45 (v approaches v - delta v) bands with v = delta v to v = 9, and for DF of the rotational lines for both P- and R-branches in 78 (v approaches v- delta v) bands with v = delta v to v = delta v to v = 12. The line ... |
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| Flow-Tube Studies of Vibrational Energy Transfer HF(v) + HF, DF(v) + HF, and DF(v) + D2 Systems. |
23 AUG 1976 |
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| Authors:
Munson A Kwok; Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF AEROPHYSICS LAB
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| A medium-pressure (1-Torr), large-diameter (10-cm) flow tube has been used to measure rate coefficients at 298 K for (1) total relaxation (sum of vibrational-vibrational and vibrational-rotational, translational processes) of HF(v= 1,2, 3, 4, and 5) by HF, (2) relaxation of DF(1, 2, 3, and 4) by HF, and (3) overall relaxation of DF(v = 1, 2, 3, and 4) by D2. The chemically produced vibrationally excited HF or DF species ... |
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| Flow Tube Measurements of H + HF(v) Deactivation Rates. |
25 MAR 1975 |
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| Authors:
Munson A. Kwok; Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A medium-pressure flow tube is used to determine the rate constants for vibrational deactivation of HF(v = 1, 2, 3) by H-atoms by monitoring the HF vibration-rotation emission. The deactivation of HF(v) by H-atoms is found to be a very efficient energy-transfer process. The experimental results are compared with available theoretical data of Wilkins. |
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| Vibrational Relaxation of HCl (v = 1,2,3,6) by H and Cl Atoms, |
25 FEB 1975 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF
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| Rate coefficients are calculated for the collisional de-excitation of vibrationally excited HCl molecules by H and Cl atoms. Three-dimensional classical trajectories of the collisional dynamics of these reactions are calculated by using London-Eyring-Polanyi-Sato (LEPS) potential-energy surfaces. The results indicate that (1) the rapid deactivation of vibrationally excited HCl by H and Cl atoms can be explained if bound complexes are postulated for both HClH and ClHCl, (2) H- and Cl ... |
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| Reaction Rates and Energy Distributions Among Reaction Products for the H + Cl2 and Cl + H2 Reactions. |
21 FEB 1975 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| Rate coefficients have been calculated for the bimolecular exchange reactions of H with Cl2 and Cl with H2. Three-dimensional classical trajectories of the collision dynamics of these reactions have been calculated by means of the London-Eyring-Polanyi-Sato (LEPS) potential energy surfaces. Energy transfer and distribution are discussed. |
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| Vibrational Deactivation of H2(v = 1) by H-Atoms. |
29 MAR 1974 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| Rate constants are calculated for the vibrational relaxation of H2(v = 1) by H-atoms. A classical three-dimensional trajectory calculation is carried out to determine if both reactive and nonreactive collisions play an important role in the dynamics of this reaction on a London-Eyring-Polanyi-Sato (LEPS) potential energy hypersurface. The results of this calculation are compared with available experimental data. (Author) |
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| Monte Carlo Calculations of Reaction Rates and Energy Distributions Among Reaction Products: Reactions of HF and DF with H- and D-Atoms. |
15 JAN 1974 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| Rate coefficients are calculated for the reactions of H- and D-atoms with vibrationally excited HF and DF molecules. Three-dimensional classical trajectories of the collision dynamics of these reactions have been calculated by means of the London-Eyring-Polanyi-Sato (LEPS) potential energy surface. The Monte Carlo procedure is used to start each collision trajectory. This report indicates that (1) chemical exchange provides an efficient mechanism for relaxing vibrationally excited HF and DF molecules ... |
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| Monte Carlo Calculations of Reaction Rates and Energy Distribution Among Reaction Products H + F2 to HF + F and D + F1 to DF + F, |
03 DEC 1973 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A three-dimensional classical trajectory calculation is made of the collision dynamics of the exothermic reactions H + F2(v, J) to HF(v',J') + F and D + F2(v,J) to DF(v',J) + F by means of a modified London-Eyring-Polanyi-Sato (LEPS) potential energy surface. Trajectory calculations are used to establish the anti-Morse interaction potentials for the first repulsive states of HF and F2. Reaction rate constants are presented for reaction directly into specific ... |
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| Monte Carlo Calculations of Reaction Rates F+HF(v) yields HF(v)+F and F+DF(v) yields DF(v)+F. |
04 APR 1973 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| Rate constants have been calculated for vibrational relaxation of HF(v) and DF(v) by F atoms with v = 1, 2, 3, and 6. Three-dimensional classical trajectories of the collision dynamics of these exothermic reactions were calculated by means of the modified London-Eyring-Polanyi-Sato (LEPS) potential energy surface used in a previous paper to calculate rate constants for the reactions between H atoms and F2 and D atoms and F2. The Monte ... |
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| Monte Carlo Calculations of Reaction Rates and Energy Distribution among Reaction Products F+HD yields HF+D and F+HD yields DF+H. |
30 MAR 1973 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| Rate constants are calculated for the exothermic reactions F + HD (v, J) to HF(v', J') + D and F + HD(v, J) to DF(v', J') + H by analyzing the results of three-dimensional classical trajectories on an assumed London-Eyring-Polanyi-Sato (LEPS) potential energy surface. The Monte Carlo method is used to start each collision trajectory. Data are presented for the temperature dependences of (1) the overall rate constants, (2) the ... |
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| Monte Carlo Calculations of Reaction Rates and Energy Distributions Among Reaction Products. F + D2 to DF + D. |
28 FEB 1973 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A three-dimensional classical trajectory analysis is used to determine the reaction dynamics of the reaction F + D2(v,J) to DF(v',J') + D on an assumed London-Erying-Polanyi-Sato (LEPS) potential energy surface. Monte Carlo procedures are used to start each collision trajectory. Data are presented of the temperature dependences of energy distributions of the reaction products and rate constants for formation of DF in specific vibrational and rotational states. By means of ... |
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| Monte Carlo Calculations of Reaction Rates H + HF(v) yielding H2(v') + F and H + HF(v) yielding HF(v') + H. |
15 NOV 1972 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A total of 10,000 three-dimenional classical trajectories on a semi-empirical potential energy surface were computed for collisions of H atoms with vibrationally excited HF, chemical effects provide an important mechanism for the efficient relaxation of HF in collision with H, and the deactivation rates are extremely fast. Both theory and experiment indicate that the rate of deactivation of vibrationally excited hydrogen fluoride is amost gas kinetic. Rate coefficients are provided ... |
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| Monte Carlo Calculations of Reaction Rates and Energy Distributions Among Reaction Products F + H2 yields HF + H, |
15 SEP 1972 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A three-dimensional, classical trajectory calculation is made of the collision dynamics of the reaction F + H2(v,J) to HF(v',J') + H by means of the London-Eyring-Polanyi-Sato (LEPS) potential energy surface. Monte Carlo procedures are used to start each collision trajectory. A discussion is presented of the temperature dependence of the relative rates of formation of vibrationally excited hydrogen fluoride. By means of this calculation, it can be predicted that 71% ... |
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| Absolute Rates of the Reactions H2(+)F and F2(+)H. |
18 MAR 1971 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| Absolute reaction rate theory has been used to calculate the rate constants for the exchange reactions H2 + F = HF + H and F2 + H = HF + F. Three-atom potential energy surfaces for collinear motion have been determined for these two reactions by using the London-Eyring-Polany-Sato technique for construction of such surfaces. Three-dimensional plots are presented of the potential energy surfaces, gradient of the potential energy surfaces, ... |
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| Role of Active Modes in Unimolecular Reactions. Volume 2. Thermal Decomposition of Fluoroform and Methane. |
15 DEC 1970 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A recently developed model has been applied to the Rice-Ramsperger-Kassel-Marcus (RRKM) theory of unimolecular reactions to calculate rate constants for the thermal decomposition of fluoroform and methane. Unlike previous failures to determine the pressure dependence for the thermal decomposition of fluoroform and methane by means of the quantum statistical RRKM theory of unimolecular reactions, the new model correlates available experimental data for both fluoroform and methane. In addition, the new ... |
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| Role of Active Modes in Unimolecular Reactions. Volume I. Thermal Decomposition of Sulfur Tetrafluoride and Sulfur Hexafluoride. |
15 DEC 1970 |
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| Authors:
Roger L. Wilkins; Jerry F. Bott; Theodore A. Jacobs; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A new modification is introduced in the theory of unimolecular reactions. This modification assumes that not all normal vibrations of the active molecule are active modes. The modified theory has been used to investigate the thermal decomposition of sulfur tetrafluoride and sulfur hexafluoride in a background of inert atoms. Unlike previous failures to determine the pressure dependence for the thermal decomposition of these highly symmetrical molecules by means of the ... |
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| POLARIZABILITY OF MOLECULAR HYDROGEN. |
JUL 1968 |
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| Authors:
Roger L. Wilkins; Howard S. Taylor; AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
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| A summation technique is used to calculate the static dipole electric polarizabilities of molecular hydrogen. The technique requires a complete set of single-particle Hartree-Fock states. The occupied Hartree-Fock orbitals for molecular hydrogen are bound, and the complementary set of Hartree-Fock orbitals all lie in the continuum. Such a basis set permits one to evaluate the required sums by integrating over the excited states. The uncoupled Hartree-Fock model is used to ... |
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| ELASTIC SCATTERING OF LOW-ENERGY ELECTRONS FROM MOLECULAR HYDROGEN, |
JUN 1967 |
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| Authors:
Roger L. Wilkins; Howard S. Taylor; AEROSPACE CORP EL SEGUNDO CALIF LABS DIV
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| The cross sections for elastic scattering of low energy electrons by molecular hydrogen are calculated by solving numerically the continuum Hartree-Fock equations for an electron moving in the potential field of the neutral homonuclear diatomic hydrogen molecule. Hartree-Fock equations make full allowance for electron exchange. The cross sections for elastic scattering of electrons by molecular hydrogen are treated with and without the assumption of electron exchange. The theoretical agreement in ... |
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| A NUMERICAL SINGLE-CENTER SELF-CONSISTENT FIELD FUNCTION FOR THE HYDROGEN MOLECULE, |
JUN 1967 |
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| Authors:
Roger L. Wilkins; Howard S. Taylor; AEROSPACE CORP EL SEGUNDO CALIF LABS DIV
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| A Hartree-Fock single determinant wave function is calculated for the normal state (1)Sigma(+)g of the hydrogen molecule. The one-electron molecular orbitals in this determinant are expanded up to fourth-order terms as a product of a series of spherical harmonics and radial wave functions about the molecular midpoint of the molecule. The potential field caused by the nuclei is expanded in spherical harmonics up to eighth-order terms, and the complete Hartree-Fock ... |
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| MONTE CARLO CALCULATIONS OF CROSS SECTIONS OF ELECTRON-POSITIVE MOLECULAR ION DISSOCIATIVE RECOMBINATION. |
DEC 1965 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF
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| In a recent paper, Bauer and Wu proposed a self-consistent model for the application of perturbation theory to calculating the general order of magnitude of cross sections of electron-positive molecular ion dissociative recombination. In applying their model to the calculation on a hypothetical system of electron capture by molecular hydrogen ions, it was necessary to make several approximations, without which it would have been exceedingly difficult to evaluate certain matrix ... |
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| CONTINUOUS ABSORPTION COEFFICIENTS OF CHLORINE, |
10 JAN 1964 |
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| Authors:
Roger L. Wilkins; AEROSPACE CORP EL SEGUNDO CALIF
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| Continuous absorption coefficients of chlorine have been calculated at wavelengths between 4000 and 2300 angstroms for temperatures from 291 to 2400 K. The necessary partial absorption coefficients were calculated on a high-speed electronic digital computer. The resulting total absorption coefficients for chlorine agree well enough with the available experimental data to verify existing theory. (Author) |
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Reports by Author
