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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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Integrated Bragg X ray scattering intensities for monatomic crystalline lattices, considering thermal diffuse component contribution
X-ray diffractometer for single crystal damage studies, and theoretical evaluation of cesium gas scattering problem
High altitude atmospheric density measurements using X-ray or gamma ray backscatter and rocket sounding techniques
Space astronomy, considering UV spectra of Jupiter and Venus, stellar energy distributions, interstellar scattering and X-ray observations
Calculation of approximate expression for van der Waals energy with aid of variationally determined polarizabilities
Characteristics of modulated energetic electron precipitation occurring during auroral substorms
Microburst precipitation of energetic electrons into auroral zone
Relativistic electron energy loss due to inverse Compton scattering from cosmological blackbody radiation, noting diffuse X ray background implication for electron source strength
Fe rich Fe-Al alloys single crystals, determining three dimensional order and atomic displacements coefficients by X ray diffuse scattering
High resolution muonic X-ray studies on nuclear isotope interactions
Members from industry and federal agencies of the United States have developed a collaborating group focused on improving the understanding of the atomization processes common to gas turbine engines. The group is aimed on providing high quality data using x-ray diagnostics in the internal geometry and the near-field dense spray as well as optical diagnostics in the visible spectrum, downstream of the nozzle. This paper reports results from one of the two non-proprietary injectors designs from the group: the primary-secondary injector. In particular, we characterize the spray from only the primary, pressure-swirl atomizing circuit using water through the nozzle. We observed Sauter mean diameter decreased with increased water pressure drop across the nozzle. SMD was also collected at three axial distances and showed decreased size with distance from the nozzle. Planar laser sheet droplet scattering provided qualitative assessment of the spray. Higher water pressure drops provided better atomization than lower pressure drops. The addition of swirling air flow through the injector alleviates and improves the atomization quality, particularly at the lower water pressure drops.
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IXPE has provided for the first time detailed energy- and time-resolved X-ray polarimetry of Z-type neutron star low-mass X-ray binaries (NS-LMXBs) as they move along their color-color diagrams (CCDs). These sources can reach the highest polarization observed for NS-LXMBs in the 2–8 keV range when they move along the horizontal branch. In a previous paper, we characterized the spectral state of a sample of Z-sources using the CCD and estimated the polarization with model-independent analysis. Here, we present detailed spectropolarimetric analysis for each source on each branch using data from IXPE, NICER, and NuSTAR. The continuum X-ray emission of all the sources is well described with a combination of thermal accretion disk emission plus a harder Comptonized component. In addition, reflection features, in particular the relativistically broadened Fe Kα line, are observed for our sources, except GX 5–1. For most of the sources and branches, the main contribution to the X-ray emission and polarization is due to Comptonization: moving from the horizontal branch (HB) to the normal branch (NB), the polarization degree (PD) in the 2–8 keV band varies from about 6% to 3–4%, while the PD is loosely constrained in the flaring branch (FB), due to the shorter exposures. These PD values are significantly higher than theoretical expectations for typical spreading or boundary layer configurations. The polarization of the disk is generally lower (below 3%) but still higher than predictions for an electron scattering-dominated, plane-parallel atmosphere above the disk observed at the corresponding inclination. Moreover, the polarization angle (PA) of the disk seems to be significantly misaligned and not perpendicular to that of Comptonization. We find no correlation between the polarization signal and the inclination, nor with the contribution of reflected photons throughout the Z-track.
Electron momentum density in diamond, graphite and carbon black from Compton profile measurement by X ray scattering vector
X ray line emission from Sco X-1 using Monte Carlo estimates of spectral distribution of scattered photons in terms of Fe line and cosmic abundance
Diffuse cosmic X rays produced by Compton scattering of far IR radiation on cosmic ray electrons
X ray spectrum measurement of Scorpius X-1 by Bragg spectrometer, explaining emission or absorption absence by source model with line weakened by electron scattering