Search results for "Photon"
showing 10 items of 3171 documents
Ab initio modeling of radiation damage in MgF2 crystals
2014
Abstract MgF2 with a rutile structure is important radiation-resistant material with numerous applications due to its transparency from vacuum ultraviolet to infrared range of photon energies. We present and discuss the results of calculations for basic radiation defects in this crystal. The study is based on the large scale ab initio DFT calculations using hybrid B3PW exchange–correlation functional and atomic basis set. We analyzed the electronic structure, atomic displacements, charge density distribution as well as defect formation energies using large supercells. We compared properties of close and well separated F−H (Frenkel) defect pairs as well as individual defects. We simulated al…
Intra-atomic versus interatomic process in resonant Auger spectra at the TiL23edges in rutile
2001
The two components of the Ti ${L}_{23}{M}_{23}V$ Auger transition recorded on a stoichiometric rutile crystal are identified as ${L}_{2}{M}_{23}V$ and ${L}_{3}{M}_{23}V$ contributions. This assignment is evidenced by concordant data relative to resonances of the LMV decay at the Ti ${L}_{23}$ thresholds and to Auger emission recorded in coincidence with the ${2}_{1/2}$ and ${2}_{3/2}$ photoemission at a photon energy far above the Ti ${L}_{23}$ edges. The ${L}_{3}{M}_{23}V$ transition is shown to follow either the direct photoexcitation of a ${2}_{3/2}$ electron or the fast Coster-Kronig decay of a ${2}_{1/2}$ photohole. Although specific LMV contributions related to valence orbitals are id…
The influence of sigma and pi acceptors on two-photon absorption and solvatochromism of dipolar and quadrupolar unsaturated organic compounds.
2003
Two-photon absorption cross sections delta and solvatochromic properties were determined for a series of quadrupolar and dipolar compounds by using femtosecond excitation in the spectral range between 710 and 960 nm. The compounds investigated were distyrylbenzenes and polyenes bearing appropriate pi or sigma acceptors. The delta values for the centrosymmetric compounds trans, trans- 1,4-bis[2-(2',5'-dihexyloxy)phenylethenyl]-2,3,5,6-tetrafluorobenzene (6), trans, trans-1,4-bis[2-(4'-dibutylamino)phenylethenyl]- 2,3,5,6-tetrafluorobenzene (2), trans, trans-1,4-bis[2-(4'dimethylamino)phenylbutadienyl]- 2,3,5,6-tetrafluorobenzene (7), trans,-trans-1,4-bis[2-(4'-dimethylamino)phenylethenyl]2,5…
The role of Nb in intensity increase of Er ion upconversion luminescence in zirconia
2014
It is found that Nb co-doping increases the luminescence and upconversion luminescence intensity in rare earth doped zirconia. Er and Yb-doped nanocrystalline samples with or without Nb co-doping were prepared by sol-gel method and thermally annealed to check for the impact of phase transition on luminescence properties. Phase composition and grain sizes were examined by X-ray diffraction; the morphology was checked by scanning- and high-resolution transmission electron microscopes. Both steady-state and time-resolved luminescence were studied. Comparison of samples with different oxygen vacancy concentrations and different Nb concentrations confirmed the known assumption that oxygen vacanc…
Analog Photonic Fractional Signal Processing
2018
Fil: Cuadrado Laborde, Christian. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales; España Fil: Cuadrado Laborde, Christian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cuadrado Laborde, Christian. Pontificia Universidad Católica Argentina. Facultad de Química e Ingeniería del Rosario; Argentina Fil: Poveda-Wong, Luis. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales; España Fil: Carrascosa, Antonio. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales ; España Fil: Diez, Antonio. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales; España Fil: Cruz, Jo…
Study of η and η′ Photoproduction at MAMI
2017
The reactions γp→ηp and γp→η′p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections are obtained with unprecedented statistical accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section for η photoproduction at the energies in the vicinity of the η′ threshold, W=1896 MeV (Eγ=1447 MeV). Within the framework of a revised ηMAID isobar model, the cusp, in connection with a steep rise of the η′ total cross section from its threshold, can only be explained by a strong coupling of the poorly known N(1895)1/2− …
Translational dynamics effects on the non-local correlations between two atoms
2005
A pair of atoms interacting successively with the field of the same cavity and exchanging a single photon, leave the cavity in an entangled state of Einstein-Podolsky-Rosen (EPR) type (see, for example, [S.J.D. Phoenix, and S.M. Barnett, J. Mod. Opt. \textbf{40} (1993) 979]). By implementing the model with the translational degrees of freedom, we show in this letter that the entanglement with the translational atomic variables can lead, under appropriate conditions, towards the separability of the internal variables of the two atoms. This implies that the translational dynamics can lead, in some cases, to difficulties in observing the Bell's inequality violation for massive particles.
"Table 4" of "Exclusive production of pion and kaon meson pairs in two photon collisions at LEP."
2003
Measured cross section for kaon production as a function of W.
"Table 35" of "High-$E_{\rm T}$ isolated-photon plus jets production in $pp$ collisions at $\sqrt s=$ 8 TeV with the ATLAS detector"
2018
Measured cross sections for isolated-photon plus 3jet production as a function of $\Delta\phi^{\rm jet2-jet3}$ for the range $E_{\rm T}^{\gamma} >300$ GeV.
"Table 30" of "High-$E_{\rm T}$ isolated-photon plus jets production in $pp$ collisions at $\sqrt s=$ 8 TeV with the ATLAS detector"
2018
Measured cross sections for isolated-photon plus 3jet production as a function of $\Delta\phi^{\rm \gamma-jet3}$ for the range $130< E_{\rm T}^{\gamma} <300$ GeV.