651 research outputs found
Electron-induced proton knockout from neutron rich nuclei
We study the evolution of the \eep cross section on nuclei with increasing
asymmetry between the number of neutrons and protons. The calculations are done
within the framework of the nonrelativistic and relativistic distorted-wave
impulse approximation. In the nonrelativistic model phenomenological
Woods-Saxon and Hartree-Fock wave functions are used for the proton bound-state
wave functions, in the relativistic model the wave functions are solutions of
Dirac-Hartree equations. The models are first tested against experimental data
on Ca and Ca nuclei, and then they are applied to a set of
spherical calcium isotopes.Comment: 5 pages, 2 figures. contribution to the XIX International School on
Nuclear Physics, Neutron Physics and Applications, Varna (Bulgaria) September
19-25, 201
Power-laws in recurrence networks from dynamical systems
Recurrence networks are a novel tool of nonlinear time series analysis
allowing the characterisation of higher-order geometric properties of complex
dynamical systems based on recurrences in phase space, which are a fundamental
concept in classical mechanics. In this Letter, we demonstrate that recurrence
networks obtained from various deterministic model systems as well as
experimental data naturally display power-law degree distributions with scaling
exponents that can be derived exclusively from the systems' invariant
densities. For one-dimensional maps, we show analytically that is not
related to the fractal dimension. For continuous systems, we find two distinct
types of behaviour: power-laws with an exponent depending on a
suitable notion of local dimension, and such with fixed .Comment: 6 pages, 7 figure
Collimated dual species oven source and its characterisation via spatially resolved fluorescence spectroscopy
We describe the design, construction and characterisation of a collimated, dual-species oven source for generating intense beams of lithium and caesium in UHV environments. Our design produces full beam overlap for the two species. Using an aligned microtube array the FWHM of the output beam is restricted to ~ 75 milliradians, with an estimated axial brightness of 3.6x10[superscript]14 atoms s[superscript]-1 sr[superscript]-1 for Li and 7.4x10[superscript]15 atoms s[superscript]-1 sr[superscript]-1 for Cs. We measure the properties of the output beam using a spatially-resolved fluorescence technique, which allows for the extraction of additional information not accessible without spatial resolution
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