38,145 research outputs found
Measurement of the proton light response of various LAB based scintillators and its implication for supernova neutrino detection via neutrino-proton scattering
The proton light output function in electron-equivalent energy of various
scintillators based on linear alkylbenzene (LAB) has been measured in the
energy range from 1 MeV to 17.15 MeV for the first time. The measurement was
performed at the Physikalisch-Technische Bundesanstalt (PTB) using a neutron
beam with continuous energy distribution. The proton light output data is
extracted from proton recoil spectra originating from neutron-proton scattering
in the scintillator. The functional behavior of the proton light output is
described succesfully by Birks' law with a Birks constant kB between (0.0094
+/- 0.0002) cm/MeV and (0.0098 +/- 0.0003) cm/MeV for the different LAB
solutions. The constant C, parameterizing the quadratic term in the generalized
Birks law, is consistent with zero for all investigated scintillators with an
upper limit (95% CL) of about 10^{-7} cm^2/MeV^2. The resulting quenching
factors are especially important for future planned supernova neutrino
detection based on the elastic scattering of neutrinos on protons. The impact
of proton quenching on the supernova event yield from neutrino-proton
scattering is discussed.Comment: 12 pages, 17 figures, 4 tables, updated version for publication in
Eur.Phys.J.
The Kinetic Energy of Hydrocarbons as a Function of Electron Density and Convolutional Neural Networks
We demonstrate a convolutional neural network trained to reproduce the
Kohn-Sham kinetic energy of hydrocarbons from electron density. The output of
the network is used as a non-local correction to the conventional local and
semi-local kinetic functionals. We show that this approximation qualitatively
reproduces Kohn-Sham potential energy surfaces when used with conventional
exchange correlation functionals. Numerical noise inherited from the
non-linearity of the neural network is identified as the major challenge for
the model. Finally we examine the features in the density learned by the neural
network to anticipate the prospects of generalizing these models
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