Intermediate-state theory of single-particle resonances.
Intermediate state in oxygen observed as very sharp scattering resonance
ELECTRON STATE↗
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Single-particle calculations in nuclear fission.
Effective mass in nuclear deformational Hamiltonian calculated by asymptotic approximation method which is two orders of magnitude better than liquid drop model
HAMILTONIAN↗
Total single-particle energy of isotropic semiconductors.
Total single particle energy of isotropic semiconductors, discussing energy spectra of bonded crystals for diamond and silicon
Van Vechten, J. A.↗
A systematic method of calculating reduced matrix elements of single-particle operators
Inelastic transition density method for calculating reduced matrix elements of single particle operators
Braley, R. C.↗
Analysis of suspended solids by single-particle scattering
Light scattering by individual particulates is used in a multiple-detector system to categorize the composition of suspended solids in terms of broad particulate categories. The scattering signatures of red clay and taconite tailings, the two primary particulate contaminants in western Lake Superior, along with two types of asbestiform fibers, amphibole and chrysolite, were studied in detail. A method was developed to predict the concentration of asbestiform fibers in filtration plant samples for which electron microscope analysis was done concurrently. Fiber levels as low as 50,000 fibers/liter were optically detectable. The method has application in optical categorization of samples for remote sensing purposes and offers a fast, inexpensive means for analyzing water samples from filtration plants for specific particulate contaminants.
Diehl, S. R.↗
Resonant diffusion in strongly turbulent plasmas.
The effect of turbulent fluctuations on plasma particles is considered, and equations are derived which describe the evolution of macroscopic properties such as temperature and flow speed of the turbulent plasma. Initially, a diffusion equation for a single-particle distribution function averaged over an ensemble of plasmas is derived for an unmagnetized plasma. For the resonant diffusion in strongly turbulent plasmas, an ensemble of three-dimensional plasmas is considered with an approximately homogeneous and stationary distribution of random electromagnetic fluctuations. For each realization, the single-particle distribution function satisfies the Vlasov equation.
Birmingham, T. J.↗
Deformed Brueckner-Hartree-Fock calculation for light nuclei
For the first time the Brueckner-Hartree-Fock (BHF) method was applied to nuclei whose intrinsic structure is nonspherical. One aim was to investigate whether the energy dependent reaction matrix calculated from a realistic nucleon-nucleon interaction leads to deformations similar to, or different from, those obtained from energy independent interactions in Hartree-Fock (HF) calculations. Reaction matrix elements were calculated as a function of starting energy for the Hamada-Johnston interaction, using a Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single-particle energies, radii, and shape deformations of the intrinsic state in unrenormalized as well as renormalized BHF are discussed and compared with previous HF studies. Results are presented for C-12, O-16, and Ne-20.
Braley, R. C.↗
Cloud microstructure as determined by an optical cloud particle spectrometer.
Use of an improved single-particle light-scattering instrument for measurement of cloud microstructure in field studies. Cloud particle size and number information is measured over 12 sizing intervals, in the range from 4 to 85 microns in diameter. The microstructure can be observed in real time and with a spatial resolution not previously reported. The general features of water cloud droplet size and number distributions are consistent with previous direct capture and replication studies. The transition from water to ice phase regions in cumuliform clouds can be inferred from dramatic changes observed in the distribution features. Results are also presented for stratus and cirrus cloud penetrations.
Ryan, R. T.↗
Electromagnetic scattering by arbitrarily oriented ice cylinders.
The scattering of electromagnetic waves by arbitrarily oriented, infinitely long circular cylinders is solved by following the procedures outlined by van de Hulst. The far-field intensities for two cases of a linearly polarized incident wave are derived. The scattering coefficients involve the Bessel functions of the first kind, the Hankel functions of the second kind, and their first derivatives. Calculations are made for ice cylinders at three wavelengths: 0.7, 3, and 10 microns. The numerical results of intensity coefficients are presented as functions of the observation angle. A significant cross-polarized component for the scattered field, which vanishes only at normal incidence, is obtained. It is also shown that the numerous interference maxima and minima of the intensity coefficients due to single-particle effects depend on the size parameter as well as on the oblique incident angle.
Liou, K.-N.↗
Molecular beams in chemistry.
The molecular-beam technique is a means for producing isolated atoms or molecules within a narrow range of speed and solid angle. The phenomena studied with molecular beams can be classified as single-particle interactions, many-particle interactions, and two particle-interactions. The results of scattering experiments fall into two categories including collisions that do not result in atomic rearrangements and collisions that do. Experimental methods are discussed, giving attention to low-energy beams, high-energy beams, and intermediate-energy beams. Examples are presented to illustrate the information that can be obtained from elastic, inelastic, and reactive scattering.
Jordan, J. E.↗
Ion kinematics in a plasma focus.
The results of numerical integrations of three-dimensional equations of motion of ions subject to given electric and magnetic fields are presented. The fields represent those which may exist in the pinch phase of the plasma focus, although here they depend only on the radial coordinate. The ions initially have Maxwellian velocity distributions, and their trajectories are interpreted in terms of single-particle constants of the motion. Two models of the axial electric field Ez are considered. For strong Ez away from the axis, there is a cyclotron acceleration which leads to ion heating. For positive Ez on the axis, ions within a Larmor radius of the axis undergo very efficient acceleration; the results for this new model are in general agreement with experimental results.
Gary, S. P.↗
K-LL Auger transition probabilities for elements with low and intermediate atomic numbers
Radiationless K-LL transition probabilities have been calculated nonrelativistically in j-j coupling and in intermediate coupling, without and with configuration interaction, for elements with atomic numbers from 13 to 47. The system is treated as a coupled two-hole configuration. The single-particle radial wave functions required in the calculation of radial matrix elements, and in the calculation of mixing coefficients in the intermediate-coupling scheme, were obtained from Green's atomic independent-particle model. Comparison with previous theoretical work and with experimental data is made. The effects of intermediate coupling, configuration interaction, and relativity are noted.
Chen, M. H.↗
Ground-state energies of simple metals
A structural expansion for the static ground-state energy of a simple metal is derived. Two methods are presented, one an approach based on single-particle band structure which treats the electron gas as a nonlinear dielectric, the other a more general many-particle analysis using finite-temperature perturbation theory. The two methods are compared, and it is shown in detail how band-structure effects, Fermi-surface distortions, and chemical-potential shifts affect the total energy. These are of special interest in corrections to the total energy beyond third order in the electron-ion interaction and hence to systems where differences in energies for various crystal structures are exceptionally small. Preliminary calculations using these methods for the zero-temperature thermodynamic functions of atomic hydrogen are reported.
Hammerberg, J.↗
A photometric function for diffuse reflection by particulate materials
A photometric function is proposed to describe the diffuse reflection of radiation by particulate materials. Both multiple scattering and the dominant effects of particle shadowing are included and the function is verified by comparisons with the photometries of laboratory surfaces. Brightness measurements of planetary and other diffusely scattering surfaces can be used to calculate the brightness for geometries other than those used in the measurements and for which the Minnaert function does not apply. The measurements also can be directly related to such surface characteristics as particle size, single-particle albedo, and compactness.
Meador, W. E.↗
Catastrophic rupture of lunar rocks - A Monte Carlo simulation
A computer model based on Monte Carlo techniques was developed to simulate the destruction of lunar rocks by 'catastrophic rupture' due to meteoroid impact. Energies necessary to accomplish catastrophic rupture were derived from laboratory experiments. A crater-production rate derived from lunar rocks was utilized to calculate absolute time scales. Calculated median survival times for crystalline lunar rocks are 1.9, 4.6, 10.3, and 22 m.y. for rock masses of 10, 100, 1000, and 10,000 g, respectively. Corresponding times of 6, 14.5, 32, and 68 million years are required before the probability of destruction reaches 0.99. These results are consistent with absolute exposure ages measured on returned rocks. Some results also substantiate previous conclusions that the catastrophic-rupture process is significantly more effective in obliterating lunar rocks than mass wasting by single-particle abrasion. The view is also corroborated that most rocks presently on the lunar surface either are exhumed from the regolith or are fragments of much larger boulders rather than primary ejecta excavated from pristine bedrock.
Hoerz, F.↗
Turbulent measurements in supersonic boundary layer flows using laser velocimetry
Laser velocimetry has been applied successfully in the measurement of mean velocities and Reynolds stresses in a zero pressure gradient, Mach 2.9 boundary layer, and upstream and downstream of a two-dimensional, shock-wave boundary layer interaction for the same Mach number. The Reynolds stresses were obtained using a one-component, dual-scatter laser velocimeter operated in a manner analogous to the 'slanted hot-wire' technique. Signal processing was of the single-particle counting type which permitted measurements to be made using only the naturally occurring particles in the tunnel air stream for light scattering. The results for the shock-wave boundary layer interaction are presented along with hot-wire anemometer and pitot-static pressure measurements obtained in the same flow. Also, a data acquisition scheme for use with a two-component laser velocimeter is presented which should provide even better accuracies in future studies.
Johnson, D. A.↗
Laboratory observations of RF emission at plasma electron frequency and n + 1/2 times the electron cyclotron frequency in electron beam-plasma and beam-beam interactions
Electric field emissions at frequencies of (n + 1/2) times the electron cyclotron frequency have been generated in a large-scale electron beam experiment in a vacuum facility. These emissions arise when a contrastreaming beam configuration exists, the primary beam consisting of monoenergetic electrons (50 eV to 5 keV) and the other beam of lower-energy backscattered secondary electrons. It is suggested that the same mechanism could also be the source of the observed 3/2 times the electron cyclotron frequency emissions at auroral latitudes. In the absence of the beam-beam instability, weak oscillations were observed at the plasma frequency. In the latter case no significant modifications of the primary beam velocity distribution occurred, and the beam configuration is adequately described by single-particle motion in the ambient magnetic field.
Bernstein, W.↗
Quasi-microscope concept for planetary missions - Stereo
The quasi-microscope has been used for stereo pictures using a small aperture placed at the right and left over the entrance aperture. A 16-degree stereo view angle yields an enhanced stereo effect. When viewed upward through a transparent support, all grains come into focus. The technique may be used for determining mineral constituents on the basis of cleavage and fracture patterns, grain details, and surface slopes used in estimating single-particle albedo and the illumination of scattering profiles.
Burcher, E. E.↗