6,377 research outputs found
Light propagation and fluorescence quantum yields in liquid scintillators
For the simulation of the scintillation and Cherenkov light propagation in
large liquid scintillator detectors a detailed knowledge about the absorption
and emission spectra of the scintillator molecules is mandatory. Furthermore
reemission probabilities and quantum yields of the scintillator components
influence the light propagation inside the liquid. Absorption and emission
properties are presented for liquid scintillators using 2,5-Diphenyloxazole
(PPO) and 4-bis-(2-Methylstyryl)benzene (bis-MSB) as primary and secondary
wavelength shifter. New measurements of the quantum yields for various aromatic
molecules are shown.Comment: 11 pages, 3 figures, 1 tabl
Correlations in nuclear energy recurrence relations
The excitation energies of states belonging to the ground state bands of
heavy even-even nuclei are analysed using recurrence relations. Excellent
agreement with experimental data at the 10 keV level is obtained by taking into
account strong correlations which emerge in the analysis. This implies that the
excitation energies can be written as a polynomial of maximum degree four in
the angular momentum.Comment: 4 pages, 1 figure, 1 table, 9 reference
Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection
Over the course of several decades, organic liquid scintillators have formed
the basis for successful neutrino detectors. Gadolinium-loaded liquid
scintillators provide efficient background suppression for electron
antineutrino detection at nuclear reactor plants. In the Double Chooz reactor
antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded
scintillator is utilized for the first time. Its large scale production and
characterization are described. A new, light yield matched metal-free companion
scintillator is presented. Both organic liquids comprise the target and "Gamma
Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table
Cavity QED determination of atomic number statistics in optical lattices
We study the reflection of two counter-propagating modes of the light field
in a ring resonator by ultracold atoms either in the Mott insulator state or in
the superfluid state of an optical lattice. We obtain exact numerical results
for a simple two-well model and carry out statistical calculations appropriate
for the full lattice case. We find that the dynamics of the reflected light
strongly depends on both the lattice spacing and the state of the matter-wave
field. Depending on the lattice spacing, the light field is sensitive to
various density-density correlation functions of the atoms. The light field and
the atoms become strongly entangled if the latter are in a superfluid state, in
which case the photon statistics typically exhibit complicated multimodal
structures.Comment: 10 pages revtex, 13 figure
Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection
Over the course of several decades, organic liquid scintillators have formed
the basis for successful neutrino detectors. Gadolinium-loaded liquid
scintillators provide efficient background suppression for electron
antineutrino detection at nuclear reactor plants. In the Double Chooz reactor
antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded
scintillator is utilized for the first time. Its large scale production and
characterization are described. A new, light yield matched metal-free companion
scintillator is presented. Both organic liquids comprise the target and "Gamma
Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table
Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection
Over the course of several decades, organic liquid scintillators have formed
the basis for successful neutrino detectors. Gadolinium-loaded liquid
scintillators provide efficient background suppression for electron
antineutrino detection at nuclear reactor plants. In the Double Chooz reactor
antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded
scintillator is utilized for the first time. Its large scale production and
characterization are described. A new, light yield matched metal-free companion
scintillator is presented. Both organic liquids comprise the target and "Gamma
Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table
Classical and Quantum Correlation Functions for a Ring Model
Classical and quantum correlation functions are derived for a system of
non-interacting particles moving on a circle. It is shown that the decaying
behaviour of the classical expression for the correlation function can be
recovered from the strictly periodic quantum mechanical expression by taking
the limit that the Planck's constant goes to zero, after an appropriate
transformation.Comment: 8 page
Science is perception: what can our sense of smell tell us about ourselves and the world around us?
Human sensory processes are well understood: hearing, seeing, perhaps even tasting and touchâbut we do not understand smellâthe elusive sense. That is, for the others we know what stimuli causes what response, and why and how. These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that ⊠smells. I report, here, the status quo theories for olfaction, highlighting what we do not know, and explaining why dismissing the perception of the input as âtoo subjectiveâ acts as a roadblock not conducive to scientific inquiry. I outline the current and new theory that conjectures a mechanism for signal transduction based on quantum mechanical phenomena, dubbed the âswipe cardâ, which is perhaps controversial but feasible. I show that such lines of thinking may answer some questions, or at least pose the right questions. Most importantly, I draw links and comparisons as to how better understanding of how small (10âs of atoms) molecules can interact so specially with large (10â000âs of atoms) proteins in a way that is so integral to healthy living. Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example
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