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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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MHD power generator in which ionization of alkali atoms occurs by collision with excited noble gas atoms, calculating velocity-dependent cross section
Abstract We measured the Born cross sections for the processe + e − →ωη′ at 22 center-of-mass energies from 2.000 to 3.080 GeV with the BESIII detector at the BEPCII collider. We observed a resonant structure with a statistical significance of 9.6σ. A Breit-Wigner fit determines its mass to beM R = (2153±30±31) MeV/c 2 and its width to be Γ R = (167±77±7) MeV, where the first uncertainties are statistical and the second are systematic.
The production cross section of inclusive isolated photons has been measured by the ALICE experiment at the CERN LHC in pp collisions at centre-of-momentum energy of $\mathbf {\sqrt{\textit{s}}=13}$ TeV collected during the LHC Run 2 data-taking period. The measurement is performed by combining the measurements of the electromagnetic calorimeter EMCal and the central tracking detectors ITS and TPC, covering a pseudorapidity range of and a transverse momentum range of |η γ | < 0.67 and a transverse momentum range 7 < p$^{γ}_{T}$ < 200 GeV/c. The result extends to lower p$^{γ}_{T}$ and x$^{γ}_{T}$ = 2p$^{γ}_{T}$/$\sqrt{s}$ ranges, the lowest x$^{γ}_{T}$ of any isolated photon measurements to date, extending significantly those measured by the ATLAS and CMS experiments towards lower p$^{γ}_{T}$ at the same collision energy with a small overlap between the measurements. The measurement is compared with next-to-leading order perturbative QCD calculations and the results from the ATLAS and CMS experiments as well as with measurements at other collision energies. The measurement and theory prediction are in agreement with each other within the experimental and theoretical uncertainties.
This report examines narrow slot maximum versus average transmission cross sections and the resulting directivity gain. Other aperture shapes at high frequencies are also briefly discussed.
In this report, we describe the corrections necessary for neutron scattering cross section measurements in experiments which use finite-geometry scattering samples. A new Geant4 based framework was developed to calculate these corrections which has been benchmarked against a well-measured test case. This framework also calculates the outgoing neutron energy dependence of the correction factors, which is crucial when resolving individual final states in the scatterer is not possible.
Stopping cross sections for helium plus and low atomic number elements over energy range of 65 to 180 keV -nuclear physics
Point matching approximate method for investigating electromagnetic propagation of waveguides with complicated cross sections
Charge exchange cross section between neutral and positive nitrogen
Calculation method for wind tunnel wall interference velocities for tunnels of arbitrary cross section
Average cross sections for nuclear reaction for gamma radiation spectrum of fission products
Bremsstrahlung cross sections formulated with Dirac wave functions for screened and unscreened nuclear electrostatic fields
Numerical calculation of capture cross sections between ions and polar molecules
Mie total and differential backscattering cross sections at laser wavelengths for Junge size distribution aerosol models
Jet-wake cross section analysis for jet exhausting in free stream flow
Absorption cross sections of minor constituent gases in planetary atmospheres from 1050 to 2100 A
Correlation of critical heat flux for wetting fluids and channels of various cross sections
Description of a method for calculating the photoionization cross section of magnesium, using the technique of configuration reaction in the continuum. The two series of levels which give rise to autoionization near the threshold are explicitly included in the calculation. The described method is a logical extension of the basic technique developed by Atlick and Moore (1966) for similar calculations in application to helium.
Total cross sections angular distributions, and spectral distributions for the exclusive production of charged and neutral subthreshold pions produced in peripheral nucleus-nucleus collisions are calculated by using a particle-hole formalism. The pions result from the formation and decay of an isobar giant resonance state formed in a C-12 nucleus. From considerations of angular momentum conservation and for the sake of providing a unique experimental signature, the other nucleus, chosen for this work to be C-12 also, is assumed to be excited to one of its isovector (1+) giant resonance states. The effects of nucleon recoil by the pion emission are included, and Pauli blocking and pion absorption effects are studied by varying the isobar width. Detailed comparisons with experimental subthreshold pion data for incident energies between 35 and 86 MeV/nucleon are made.