SEARCH · Search NASA
Results for “Shells”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Measurement of Inflight Shell Areal Density Near Peak Velocity using a Self Backlighting Technique
Abstract not provided
Single-active electron calculations of high-order harmonic generation from valence shells in atoms for quantitative comparison with TDDFT calculations
Not Available
Direct double ionization of the Ar + M shell by a single photon
Direct double ionization of the Ar + (3p –1 ) ion by a single photon is investigated both experimentally and theoretically. The photon-ion merged-beams technique was employed at the Advanced Light Source in Berkeley, USA, to measure absolute cross sections in the energy range from 60 to 150 eV. In this range, three contributions to the double ionization of Ar + are to be expected: the removal of two 3p electrons, of a 3s and a 3p electron, and of two 3s electrons. Among the possible mechanisms leading to double ionization, the TS1 (two-step one) process dominates in the near-threshold region. In TS1, a photoelectron is ejected and, on its way out, knocks out a secondary electron. Here, this two-step mechanism is treated theoretically by multiplying the calculated cross section for direct single photoionization of a given subshell with the calculated (e, 2e) ionization probability for the ejected photoelectron to knock off a secondary electron. The calculated cross section is in very good agreement with the experiment.
Streaking single-electron ionization in open-shell molecules driven by x-ray pulses
Not Available
Dipole phase and photoelectron group delay in inner-shell photoionization
Not Available
Probing and extracting the structure of vibrating SF 6 molecules with inner-shell photoelectrons
In this paper, we propose a scheme for probing the structure of vibrating molecules with photoelectrons generated from ultrashort soft-x-ray pulses. As an example we analyze below-100-eV photoelectrons liberated from the S ( 2 p ) orbital of vibrating SF 6 molecules to image very small structural changes of molecular vibration. In particular, photoionization cross sections and photoelectron angular distributions (PAD) at nonequilibrium geometries can be retrieved accurately with photoelectrons near the shape resonance at 13 eV. Finally, this is achieved with a pump-probe scheme, in which the symmetric stretch mode is first Raman excited predominantly by a relatively short laser pulse and then later probed at different time delays by a few-femtosecond soft-x-ray pulse with photon energy near 200 eV.
Macrospin model of an assembly of magnetically coupled core-shell nanoparticles
Not Available
Strain-induced polarization enhancement in BaTi O 3 core-shell nanoparticles
Not provided.
Tuning g factors of core-shell nanoparticles by controlled positioning of magnetic impurities
Not Available
Is BaCr 2 As 2 symmetrical to BaFe 2 As 2 with respect to half 3 d shell filling?
We have performed an angle-resolved photoemission spectroscopy study of BaCr 2 As 2 , which has the same crystal structure as BaFe2As2, a parent compound BaFe 2 As 2 of Fe-based superconductors. We determine the Fermi surface of this material and its band dispersion down to 5 eV below the Fermi level. Very moderate band renormalization (1.35) is observed for only two bands. We attribute this small renormalization to enhanced direct exchange as compared to Fe in BaFe 2 As 2 , and to a larger contribution of the eg orbitals in the composition of the bands forming the Fermi surface.