Multigroup resonance-region cross sections for tungsten and depleted uranium for use in shielding calculations
Multigroup resonance region cross sections for tungsten and depleted uranium for use in shielding calculations
Lahti, G. P.↗
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Liquid oscillation frequencies on tilted cylinders for five cross-section shapes
Measurement of liquid oscillation frequencies in tilted cylindrical tanks of five different cross section shapes
Thornton, S.↗
An integral test of inelastic scattering cross sections using measured neutron spectra from thick shells of Ta, W, Mo, and Be
Inelastic scattering cross sections, using measured neutron leakage spectra from thick spherical shells of Ta, W, Mo and Be
Alexander, R. L.↗
Critical review of ultraviolet photoabsorption cross sections for molecules of astrophysical and aeronomic interest
Astrophysical and aeronomic UV molecular photoabsorption cross sections, discussing experimental techniques and associated systematic and random errors
Hudson, R. D.↗
Inelastic-electron-scattering cross-section measurements at 0.2-, 1.0-, and 2.0-MeV incident electron energies
Inelastic electron scattering cross sections and energy spectra from Al and Au targets, using magnetic analyzer with high resolution detector
Edmonson, N.↗
Bibliography of photoabsorption cross-section data
This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.
Hudson, R. D.↗
Coincidence measurement of the fully differential cross section for atomic-field bremsstrahlung
A coincidence measurement was made of the absolute cross section for electron-atomic-field bremsstrahlung, differential in photon energy, photon-emission angle, and electron scattering angle. The incident electron energy was 140 keV and the scattering materials were thin films of aluminum and gold. The data are compared to the theoretical calculations of Elwert and Haug and of Bethe and Heitler. Both theories give generally satisfactory agreement for aluminum. The Elwert-Haug theory is somewhat more accurate for gold.
Faulk, J. D.↗
Analytical representation of elastic scattering cross sections of low energy electrons by atmospheric gases
Analytical representations of the elastic scattering cross sections of electrons with energies of 0.01-1 keV in atmospheric gases of N2, O2, O are given. These representations are suitable for the Monte Carlo method.
Ivanov, V. Y.↗
SO2 and CS2 cross section data in the ultraviolet region
Using synchrotron radiation as a continuum background, the cross sections of SO2 in the 208-228 and 299-340 nm region and of CS2 in the 318-350 nm region have been measured with a bandwidth of 0.06 nm. It has been confirmed that the reported band positions of SO2 in the 170-315 nm region by Warneck et al. (1964) should all be shifted by about 0.3 nm toward shorter wavelengths. An important application of the present results is found in the SO2 and CS2 mixing ratio calculations for Venus and Io.
Wu, C. Y. R.↗
Parametrization of electron impact ionization cross sections for CO, CO2, NH3 and SO2
The electron impact ionization and dissociative ionization cross section data of CO, CO2, CH4, NH3, and SO2, measured in the laboratory, were parameterized utilizing an empirical formula based on the Born approximation. For this purpose an chi squared minimization technique was employed which provided an excellent fit to the experimental data.
Srivastava, Santosh K.↗
Energy-absorption capability and scalability of square cross section composite tube specimens
Static crushing tests were conducted on graphite/epoxy and Kevlar/epoxy square cross section tubes to study the influence of specimen geometry on the energy-absorption capability and scalability of composite materials. The tube inside width-to-wall thickness (W/t) ratio was determined to significantly affect the energy-absorption capability of composite materials. As W/t ratio decreases, the energy-absorption capability increases nonlinearly. The energy-absorption capability of Kevlar epoxy tubes was found to be geometrically scalable, but the energy-absorption capability of graphite/epoxy tubes was not geometrically scalable.
Farley, Gary L.↗
Reduction of the radar cross section of arbitrarily shaped cavity structures
The problem of the reduction of the radar cross section (RCS) of open-ended cavities was studied. The issues investigated were reduction through lossy coating materials on the inner cavity wall and reduction through shaping of the cavity. A method was presented to calculate the RCS of any arbitrarily shaped structure in order to study the shaping problem. The limitations of this method were also addressed. The modal attenuation was studied in a multilayered coated waveguide. It was shown that by employing two layers of coating, it was possible to achieve an increase in both the magnitude of attenuation and the frequency band of effectiveness. The numerical method used in finding the roots of the characteristic equation breaks down when the coating thickness is very lossy and large in terms of wavelength. A new method of computing the RCS of an arbitrary cavity was applied to study the effects of longitudinal bending on RCS reduction. The ray and modal descriptions for the fields in a parallel plate waveguide were compared. To extend the range of validity of the Shooting and Bouncing Ray (SBR) method, the simple ray picture must be modified to account for the beam blurring.
Chou, R.↗
Absorption and dissociative photoionization cross sections of NH3 from 80 to 1120 A
The total absorption, photoionization, and dissociative photoionization cross sections of ammonia have been measured from 80 to 1120 A. All possible fragment ions have been observed including doubly ionized ammonia. The absolute ionization efficiencies have also been measured in this spectral range. The appearance potentials of the fragment ions have been measured and are compared with the calculated appearance potentials derived from published heats of formation and ionization potentials of the fragments.
Samson, James A. R.↗
Parameterized cross sections for Coulomb dissociation in heavy-ion collisions
Simple parameterizations of Coulomb dissociation cross sections for use in heavy-ion transport calculations are presented and compared to available experimental dissociation data. The agreement between calculation and experiment is satisfactory considering the simplicity of the calculations.
Norbury, John W.↗
Calculation of turbulence-driven secondary motion in ducts with arbitrary cross section
Calculation methods for turbulent duct flows are generalized for ducts with arbitrary cross-sections. The irregular physical geometry is transformed into a regular one in computational space, and the flow equations are solved with a finite-volume numerical procedure. The turbulent stresses are calculated with an algebraic stress model derived by simplifying model transport equations for the individual Reynolds stresses. Two variants of such a model are considered. These procedures enable the prediction of both the turbulence-driven secondary flow and the anisotropy of the Reynolds stresses, in contrast to some of the earlier calculation methods. Model predictions are compared to experimental data for developed flow in triangular duct, trapezoidal duct and a rod-bundle geometry. The correct trends are predicted, and the quantitative agreement is mostly fair. The simpler variant of the algebraic stress model procured better agreement with the measured data.
Demuren, A. O.↗
Energy-absorption capability and scalability of square cross section composite tube specimens
Static crushing tests were conducted on graphite/epoxy and Kevlar/epoxy square cross section tubes to study the influence of specimen geometry on the energy-absorption capability and scalability of composite materials. The tube inside width-to-wall thickness (W/t) ratio was determined to significantly affect the energy-absorption capability of composite materials. As W/t ratio decreases, the energy-absorption capability increases nonlinearly. The energy-absorption capability of Kevlar epoxy tubes was found to be geometrically scalable, but the energy-absorption capability of graphite/epoxy tubes was not geometrically scalable.
Farley, Gary L.↗
Calculation of turbulence-driven secondary motion in ducts with arbitrary cross-section
Calculation methods for turbulent duct flows are generalized for ducts with arbitrary cross-sections. The irregular physical geometry is transformed into a regular one in computational space, and the flow equations are solved with a finite-volume numerical procedure. The turbulent stresses are calculated with an algebraic stress model derived by simplifying model transport equations for the individual Reynolds stresses. Two variants of such a model are considered. These procedures enable the prediction of both the turbulence-driven secondary flow and the anisotropy of the Reynolds stresses, in contrast to some of the earlier calculation methods. Model predictions are compared to experimental data for developed flow in triangular duct, trapezoidal duct and a rod-bundle geometry. The correct trends are predicted, and the quantitative agreement is mostly fair. The simpler variant of the algebraic stress model procured better agreement with the measured data.
Demuren, A. O.↗
A modal radar cross section of thin-wire targets via the singularity expansion method
A modal radar cross section (RCS) of arbitrary wire scatterers is constructed in terms of SEM parameters. Numerical results are presented for both straight and L-shaped wire targets and are compared to computations performed in the frequency domain using the method of moments.
Richards, M. A.↗