TY - JOUR
TI - Elastic and inelastic scattering of neutrons from 54, 56Fe and 63, 65Cu
AU - El-Kadi, S.M.
AU - Nelson, C.E.
AU - Purser, F.O.
AU - Walter, R.L.
AU - Beyerle, A.
AU - Gould, C.R.
AU - Seagondollar, L.W.
T2 - Nuclear Physics A
AB - Differential cross sections were measured at 8, 10, 12 and 14 MeV for elastic scattering of neutrons from enriched samples of 54Fe, 56Fe, 63Cu and 65Cu. Inelastic scattering to the first excited state in 54, 56Fe was also observed. For the 63, 65Cu isotopes, the inelastic cross sections for scattering to the combined group of the three (five) states were determined at 8 and 10 MeV (12 and 14 MeV). The elastic scattering data are compared to predictions of earlier global optical models. New spherical optical model representations were obtained. These data were combined with data for nickel, tin and lead to generate a new global parametrization. Comparisons of derived volume integrals for the potentials, total cross sections and potential radii are made to available information.
DA - 1982/12//
PY - 1982/12//
DO - 10.1016/0375-9474(82)90281-0
VL - 390
IS - 3
SP - 509-540
J2 - Nuclear Physics A
LA - en
OP -
SN - 0375-9474
UR - http://dx.doi.org/10.1016/0375-9474(82)90281-0
DB - Crossref
ER -
TY - JOUR
TI - Neutron Elastic Scattering Cross Sections for ^{16}O Between 9 and 15 MeV
AU - Glendinning, S. G.
AU - El-Kadi, S.
AU - Nelson, C. E.
AU - Purser, F. O.
AU - Gould, C. R.
AU - Seagondollar, L. W.
T2 - Nuclear Science and Engineering
AB - Differential cross sections are reported for elastic scattering of neutrons from 16O. Source neutrons were provided by the D(d,n)3He reaction with average neutron energies of 9.21, 9.71, 10.21, 10.70, 10.95, 11.15, 11.95, 12.45, 12.94, 13.94, and 14.93 MeV. Time-of-flight spectra were obtained for neutrons scattered by a BeO sample at 28 angles from 25 to 160 deg in 5-deg increments. Flight paths of 4 and 6 m were used. Spectra obtained with a separate beryllium sample were subtracted to remove the beryllium scattering contribution. The angular distribution data were corrected for finite source and finite sample-size effects. Legendre polynomial coefficients and total elastic scattering cross sections are reported for oxygen. The data are not well reproduced by the spherical optical model because of the many resonances in the total neutron cross section. Inclusion of resonances together with an optical model background improves the fits to the angular distribution and total cross-section data.
DA - 1982/12//
PY - 1982/12//
DO - 10.13182/nse82-a21453
VL - 82
IS - 4
SP - 393-399
J2 - Nuclear Science and Engineering
LA - en
OP -
SN - 0029-5639 1943-748X
UR - http://dx.doi.org/10.13182/nse82-a21453
DB - Crossref
ER -
TY - JOUR
TI - Elastic and Inelastic Neutron Cross Sections for Boron-10 and Boron-11
AU - Glendinning, S. G.
AU - El-Kadi, S.
AU - Nelson, C. E.
AU - Pedroni, R. S.
AU - Purser, F. O.
AU - Walter, R. L.
AU - Beyerle, A. G.
AU - Gould, C. R.
AU - Seagondollar, L. W.
AU - Thambidurai, P.
T2 - Nuclear Science and Engineering
AB - Neutron cross sections have been measured for 10B and 11B. Elastic angular distribution data for 10B are reported for incident neutron energies of 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, and 14.0 MeV. Elastic scattering data and inelastic scattering data for states at excitation energies of 2.14, 4.46, and 5.04 MeV in 11B are reported for incident neutron energies of 8.0, 9.0, 9.7, 9.9, 11.0, 12.0, 13.0, and 14.0 MeV. Legendre coefficients for angular distributions are obtained. All data are corrected for finite geometry and multiple scattering effects through a light-element Monte Carlo code. The angle integrated data for 11B are in disagreement with ENDF/B-IV for the higher neutron energies.
DA - 1982/2//
PY - 1982/2//
DO - 10.13182/nse82-a21429
VL - 80
IS - 2
SP - 256-262
J2 - Nuclear Science and Engineering
LA - en
OP -
SN - 0029-5639 1943-748X
UR - http://dx.doi.org/10.13182/nse82-a21429
DB - Crossref
ER -
TY - JOUR
TI - Neutron Elastic and Inelastic Scattering Cross Sections for Carbon-13 Between 10 and 18 MeV
AU - Dave, J. H.
AU - Gould, C. R.
AU - Seagondollar, L. W.
AU - Howell, C. R.
AU - Pedroni, R. S.
AU - Purser, F. O.
AU - Walter, R. L.
T2 - Nuclear Science and Engineering
DA - 1982/3//
PY - 1982/3//
DO - 10.13182/nse82-a19823
VL - 80
IS - 3
SP - 388-392
J2 - Nuclear Science and Engineering
LA - en
OP -
SN - 0029-5639 1943-748X
UR - http://dx.doi.org/10.13182/nse82-a19823
DB - Crossref
ER -
TY - JOUR
TI - Tritium break-up contribution to the neutron source reaction 3H(p, n) from 9 to 14 MeV
AU - Thambidurai, P.
AU - Beyerle, A.G.
AU - Gould, C.R.
T2 - Nuclear Instruments and Methods in Physics Research
AB - Zero degree neutron emission spectra have been measured in the 3H(p, n) reaction for bombarding energies from 9.77 to 14.77 MeV in 1 MeV steps. Double differential cross sections for neutrons resulting from tritium break-up reactions have been extracted and compared to previous work. The break-up cross section are small in comparison to the 3H(p, n)3He source neutron cross sections, but are not negligible. The effect of these break-up neutrons should be considered in evaluating measurements of neutron evaporation spectra induced by neutrons in the 10–14 MeV energy range.
DA - 1982/5//
PY - 1982/5//
DO - 10.1016/0029-554x(82)90106-9
VL - 196
IS - 2-3
SP - 415-420
J2 - Nuclear Instruments and Methods in Physics Research
LA - en
OP -
SN - 0167-5087
UR - http://dx.doi.org/10.1016/0029-554x(82)90106-9
DB - Crossref
ER -
TY - JOUR
TI - The 1H(7Li, n)7Be reaction as an intense MeV neutron source
AU - Dave, J.H.
AU - Gould, C.R.
AU - Wender, S.A.
AU - Shafroth, S.M.
T2 - Nuclear Instruments and Methods in Physics Research
AB - Abstract Heavy ion bombardment of hydrogen provides a number of new possibilities for mono-energetic and quasi mono-energetic neutron beam production. Close to the threshold, the strong kinematic focussing for negative Q-value reactions gives rise to intense well-collimated beams of MeV neutrons. An experimental study of 0° neutron production in the 1H(7Li, n) reaction (Q = −1.64 MeV) has been carried out from the threshold energy, 13.15 MeV, up to 22 MeV. Measured cross sections are compared to prediction based on known 7Li(p, n) cross sections. At 13.5 MeV the effective cross section reaches 4 b/sr, and the neutrons are confined within a cone of half angle 9°. Cross section predictions for 9Be, 11B and 13C bombardment of hydrogen are also presented.
DA - 1982/9//
PY - 1982/9//
DO - 10.1016/0167-5087(82)90444-6
VL - 200
IS - 2-3
SP - 285-290
J2 - Nuclear Instruments and Methods in Physics Research
LA - en
OP -
SN - 0167-5087
UR - http://dx.doi.org/10.1016/0167-5087(82)90444-6
DB - Crossref
ER -
TY - JOUR
TI - Electronic structure of deep sp-bonded substitutional impurities in silicon
AU - Bernholc, J.
AU - Lipari, N. O.
AU - Pantelides, S. T.
AU - Scheffler, M.
T2 - Physical Review B
AB - The recently-developed Green's-function method for defects in semiconductors is used to investigate the electronic properties of deep substitutional $\mathrm{sp}$-bonded impurities in Si. These impurities are grouped according to the value ${\ensuremath{\Delta}}_{z}={z}_{\mathrm{imp}}\ensuremath{-}{z}_{\mathrm{host}}$ where $z$ is the chemical valence. We choose a typical representative impurity from each group: sulfur with $\ensuremath{\Delta}z=2$ (double donor), zinc with $\ensuremath{\Delta}z=\ensuremath{-}2$ (double acceptor), and hydrogen with $\ensuremath{\Delta}z=\ensuremath{-}3$ (triple acceptor). In each case we obtain the impurity-induced state-density changes in the valence bands, and the energy positions and wave functions of the bound states in the forbidden gaps. These results are compared with earlier results for the vacancy, which may be viewed as a $\ensuremath{\Delta}z=\ensuremath{-}4$ nominal quadruple acceptor. We describe a simple physical model which explains the chemical trends as a function of $\ensuremath{\Delta}z$ and compare with available experimental data.
DA - 1982/11/15/
PY - 1982/11/15/
DO - 10.1103/physrevb.26.5706
VL - 26
IS - 10
SP - 5706–5715
SN - 0163-1829
UR - http://dx.doi.org/10.1103/physrevb.26.5706
ER -
TY - JOUR
TI - Optical properties of thin films
AU - Aspnes, D.E.
T2 - Thin Solid Films
AB - In this paper we discuss the connection between the microstructure of a heterogeneous thin film and its macroscopic dielectric response ε. Effective medium theory is developed from a solution of the Clausius-Mossotti problem from basic principles. The solution is generalized to obtain the Lorentz-Lorenz. Maxwell Garnett and Bruggeman expressions. The connection between microstructure and absolute limits to the allowed values of the dielectric response of two-phase composites is reviewed. The form of these limits for two-phase composites of known composition and two- or three-dimensional isotropy can be used to derive simple expressions for ε and also for the average fields within each phase. These results are used to analyze dielectric function spectra of semiconductor films for information about density, polycrystallinity and surface roughness. Examples illustrating the detection of unwanted overlayers and the real-time determination of nucleation growth are also given.
DA - 1982/3//
PY - 1982/3//
DO - 10.1016/0040-6090(82)90590-9
VL - 89
IS - 3
SP - 249-262
J2 - Thin Solid Films
LA - en
OP -
SN - 0040-6090
UR - http://dx.doi.org/10.1016/0040-6090(82)90590-9
DB - Crossref
ER -
TY - JOUR
TI - Local‐field effects and effective‐medium theory: A microscopic perspective
AU - Aspnes, D. E.
T2 - American Journal of Physics
AB - Standard textbook derivations of the Clausius–Mossotti (Lorentz–Lorenz) relation tend to obscure the physical origin of local-field effects by proceeding from the macroscopic dielectric function of the equivalent homogeneous system to the microscopic parameters of the model. The microscopic and macroscopic aspects can be made clearer by reversing the order, that is, by first obtaining the microscopic solution and then implementing the definition of macroscopic quantities as averages of their microscopic counterparts. This approach also leads naturally into a treatment of effective-medium theory and the description of the dielectric response of heterogeneous materials.
DA - 1982/8//
PY - 1982/8//
DO - 10.1119/1.12734
VL - 50
IS - 8
SP - 704-709
J2 - American Journal of Physics
LA - en
OP -
SN - 0002-9505 1943-2909
UR - http://dx.doi.org/10.1119/1.12734
DB - Crossref
ER -
TY - PAT
TI - Method for producing devices comprising high density amorphous silicon or germanium layers by low pressure CVD technique
AU - Adams, A. C.
AU - Aspnes, D. E.
AU - Bagley, B. G.
C2 - 1982///
DA - 1982///
PY - 1982///
ER -
TY - PAT
TI - Method for optical monitoring in materials fabrication
AU - Aspnes, D. E.
C2 - 1982///
DA - 1982///
PY - 1982///
ER -
TY - JOUR
TI - INTEGRAL-EQUATIONS FOR FLUIDS OF LINEAR-MOLECULES .3. ORIENTATIONAL ORDERING
AU - LADO, F
T2 - MOLECULAR PHYSICS
AB - The connection between the orientation correlation function, Kirkwood parameters, and spherical harmonic coefficients of the pair distribution function is obtained for classical fluids of linear molecules. The general results are illustrated with computed values from a recent integral equation solution for a fluid of hard dumbells.
DA - 1982///
PY - 1982///
DO - 10.1080/00268978200100222
VL - 47
IS - 2
SP - 313-317
SN - 0026-8976
ER -
TY - JOUR
TI - INTEGRAL-EQUATIONS FOR FLUIDS OF LINEAR-MOLECULES .2. HARD DUMBBELL SOLUTIONS
AU - LADO, F
T2 - MOLECULAR PHYSICS
AB - The reference-hypernetted chain integral equation, incorporating a spherically symmetric approximation for the bridge function B 0(12), has been numerically solved for a fluid of hard dumbells over an extended set of densities and elongations. Comparison with Monte Carlo data shows that the spherically symmetric B 0(12) is inadequate only when a large density is combined with a large elongation.
DA - 1982///
PY - 1982///
DO - 10.1080/00268978200100212
VL - 47
IS - 2
SP - 299-311
SN - 0026-8976
ER -
TY - JOUR
TI - INTEGRAL-EQUATIONS FOR FLUIDS OF LINEAR-MOLECULES .1. GENERAL FORMULATION
AU - LADO, F
T2 - MOLECULAR PHYSICS
AB - A general procedure is described that puts the practice of integral equation theory for molecular fluids on a par with that of simple fluids: any integral equation approximation can be solved for any intermolecular potential with no additional approximations beyond those inherent in numerical analysis. The essential elements are expansions in spherical harmonics and numerical evaluation of the spherical harmonic coefficients of the pair distribution function. An explicit formula is derived giving the Helmholtz free energy from the computed coefficients.
DA - 1982///
PY - 1982///
DO - 10.1080/00268978200100202
VL - 47
IS - 2
SP - 283-298
SN - 0026-8976
ER -
TY - JOUR
TI - A LOCAL THERMODYNAMIC CRITERION FOR THE REFERENCE-HYPERNETTED CHAIN EQUATION
AU - LADO, F
T2 - PHYSICS LETTERS A
AB - Rosenfeld and Ashcroft have demonstrated that the function Bor, contained in the closure of the RHNC equation, can be adapted from the hard sphere model to produce excellent results for any potential. We propose here a local thermodynamic criterion for the best Bor based on minimizing the free energy.
DA - 1982///
PY - 1982///
DO - 10.1016/0375-9601(82)90207-9
VL - 89
IS - 4
SP - 196-198
SN - 0375-9601
ER -