8 research outputs found
Search for the Neutrino Magnetic Moment in the Non-Equilibrium Reactor Antineutrino Energy Spectrum
We study the time evolution of the typical nuclear reactor antineutrino
energy spectrum during reactor ON period and the decay of the residual
antineutrino spectrum after reactor is stopped. We find that relevant
variations of the soft recoil electron spectra produced via weak and magnetic
scattering process can play a signigicant role in
the current and planned searches for the neutrino magnetic moment at reactors.Comment: 4 pages LaTeX 2.09. 4 PS figures. Resume of seminar talks given at
Kurchatov Institute, March 1999
Present and Future Experiments in Non-equilibrium Reactor Antineutrino Energy Spectrum
Considerable efforts that have been undertaken in the recent years in low
energy antineutrino experiments require further systematic investigations in
line of reactor antineutrino spectroscopy as a metrological basis of these
experiments. We consider some effects associated with the non-equilibrium of
reactor antineutrino radiation and residual antineutrino emission from spent
reactor fuel in contemporary antineutrino experiments.Comment: 7 pages, 5 figures; Talk presented at International Conference
NANP-2005, Dubna, Russia, Jun.-2005; Submitted to Phys. Atom. Nuc
Weak and Magnetic Inelastic Scattering of Antineutrinos on Atomic Electrons
Neutrino scattering on electrons is considered as a tool for laboratory
searches of the neutrino magnetic moment. We study inelastic
-scattering on electrons bound in the germanium (Z=32) and iodine
(Z=53) atoms for antineutrinos generated in a nuclear reactor core and also in
the Sr-Y and Pm artificial sources. Using the
relativistic Hartree-Fock-Dirac model, we calculate both the magnetic and weak
scattering cross sections for the recoil electron energy range of 1 to 100 keV
where a higher sensitivity to the neutrino magnetic moment could be achieved.
Particular attention is paid to the approximate procedure which allows us to
take into account the effects of atomic binding on the inelastic scattering
spectra in a simple way.Comment: 7 pages in LaTeX, 10 figures in P
Components of Antineutrino Emission in Nuclear Reactor
New scattering experiments aimed for sensitive searches of
the magnetic moment and projects to explore small mixing angle
oscillations at reactors call for a better understanding of the reactor
antineutrino spectrum. Here we consider six components, which contribute to the
total spectrum generated in nuclear reactor. They are: beta
decay of the fission fragments of U, Pu, U and
Pu, decay of beta-emitters produced as a result of neutron capture in
U and also due to neutron capture in accumulated fission fragments
which perturbs the spectrum. For antineutrino energies less than 3.5 MeV we
tabulate evolution of spectra corresponding to each of the four
fissile isotopes vs fuel irradiation time and their decay after the irradiation
is stopped and also estimate relevant uncertainties. Small corrections to the
ILL spectra are considered.Comment: LaTex 8 pages, 2 ps figure
Sensitivities of Low Energy Reactor Neutrino Experiments
The low energy part of the reactor neutrino spectra has not been
experimentally measured. Its uncertainties limit the sensitivities in certain
reactor neutrino experiments. The origin of these uncertainties are discussed,
and the effects on measurements of neutrino interactions with electrons and
nuclei are studied. Comparisons are made with existing results. In particular,
the discrepancies between previous measurements with Standard Model
expectations can be explained by an under-estimation of the low energy reactor
neutrino spectra. To optimize the experimental sensitivities, measurements for
\nuebar-e cross-sections should focus on events with large (1.5 MeV)
recoil energy while those for neutrino magnetic moment searches should be based
on events 100 keV. The merits and attainable accuracies for
neutrino-electron scattering experiments using artificial neutrino sources are
discussed.Comment: 25 pages, 9 figure
The first result of the neutrino magnetic moment measurement in the GEMMA experiment
The first result of the neutrino magnetic moment measurement at the
Kalininskaya Nuclear Power Plant (KNPP) with the GEMMA spectrometer is
presented. An antineutrino-electron scattering is investigated. A high-purity
germanium detector of 1.5 kg placed 13.9 m away from the 3 GW reactor core is
used in the spectrometer. The antineutrino flux is . The differential method is used to extract the -e
electromagnetic scattering events. The scattered electron spectra taken in 6200
and 2064 hours for the reactor ON and OFF periods are compared. The upper limit
for the neutrino magnetic moment Bohr magnetons
at 90{%} CL is derived from the data processing.Comment: 9 pages, 10 figures, 2 table