The process of neutrino interaction with
and
nuclei is studied with allowance for the effect of charge-exchange resonances. The results obtained by calculating the cross section for solar-neutrino ...capture by the isotopes
Mo and
Mo,
, are presented. Use is made of both experimental data obtained for the strength functions
in (
) and (
He,
) charge-exchange reactions and the strength functions
calculated within the theory of finite Fermi systems. The effect of the resonance structure of
on the calculated cross sections for solar-neutrino capture is studied, and the contribution of each high-lying resonance to the capture cross section
is isolated. The contributions of all components of the solar neutrino spectrum are calculated. The contribution of background solar neutrinos to the double-beta decay of
Mo nuclei is estimated.
The charge-exchange strength functions
for the isotopes
Mo are presented. Both experimental data obtained for the strength functions
in (
) and (
He,
) reactions and the strength functions
calculated ...within the self-consistent theory of finite Fermi systems are analyzed. The resonance structure of the strength function
is investigated, and the Gamow–Teller, analog, and pygmy resonances are isolated. The quenching effect manifesting itself as a sum-rule shortfall, which changes the normalization of the strength function
, is studied. It is indicated that the resonance structure of the strength function
is of decisive importance for the calculation and analysis of neutrino capture by nuclei.
This paper discusses the charge-exchange strength functions
of the isotopes
Te. The experimental data of the
strength functions obtained from (
He,
) reactions, as well as the
strength functions ...calculated in the microscopic theory of finite Fermi systems, are analyzed. The resonance structure of the strength function
is examined, and the Gamow–Teller and pygmy resonances are identified. The resonance structure of the strength function
is vital for the calculation and analysis of the process of neutrino capture by atomic nuclei.
The resonance structure of the charge-exchange strength function
and its effect on the cross sections for solar-neutrino capture by
I nuclei are analyzed. Three types of isobaric resonances are ...studied within the self-consistent theory of finite Fermi systems. These are the giant Gamow–Teller resonance; the analog resonance; and the pygmy resonances, which lie lower. The capture cross section
for solar neutrinos incident to
I nuclei is calculated with allowance for the resonance structure of the strength function
, and the effect of each resonance on the energy dependence
is analyzed. It is shown that all high-lying charge-exchange resonances should be taken into account in calculating the cross section
. The contributions of neutrinos of different origin to the structure of the cross section
are analyzed. In particular, the contribution of energetic neutrinos to the ratio of the
Xe and
Xe production rates is considered. The
Xe
Xe isotope ratio is an indicator of hard boron neutrinos in the solar spectrum.
We present the status of research and development of a new highly efficient liquid scintillator based on linear alkylbenzene and organosilicon scintillation fluor, so called NOL (Nanostructured ...Organosilicon Luminophore). The measurements of the emission kinetics under irradiation by gamma-quanta and alpha-particles were performed. The results of long term stability measurements are decribed.
Interaction of Solar Neutrinos with 128Te and 130Te Lutostansky, Yu. S.; Fazliakhmetov, A. N.; Lubsandorzhiev, B. K. ...
Bulletin of the Russian Academy of Sciences. Physics,
08/2024, Letnik:
88, Številka:
8
Journal Article
Recenzirano
The interaction of solar neutrinos with the
128
Te and
130
Te isotopes was studied taking into account the resonance structure of charge-exchange strength functions
S
(
E
). An analysis was made of ...both experimental data on the strength functions
S
(
E
) obtained in the reactions (
3
He,
t
) and the strength functions
S
(
E
) calculated in the microscopic theory of finite Fermi systems. The resonance structure of the
S
(
E
) strength function was investigated, and the Gamow–Teller, analog, and pygmy resonances were identified. The capture cross sections σ(
E
) of solar neutrinos by the two isotopes were calculated with consideration of the resonance structure of the strength function
S
(
E
), and the influence of the resonances on the energy dependence σ(
E
) was analyzed. It was shown that, when calculating the cross section σ(
E
), the resonance structure of the strength function
S
(
E
) should be taken into account.
This study has indicated that the resonance structure of the charge-exchange strength function
S
(
E
) strongly affects the cross section for solar neutrino capture σ(
E
) by the
127
I nucleus. The ...effect of each resonance on the energy dependence of σ(
E
) for an iodine detector has been analyzed. It has been shown that all high-lying charge-exchange resonances should be taken into account in the calculations of the cross section σ(
E
), and the highest energy resonances in the strength function
S
(
E
) determine the formation of the stable
126
Xe isotope at the capture of a high-energy solar neutrino by the
127
I nucleus and the subsequent neutron emission from the formed
127
Xe isotope. The calculations with the inclusion of the neutron separation energy
S
n
in the
127
Xe nucleus show that the inclusion of the neutron separation energy
S
n
reduces the neutrino capture rate, particularly for boron and hep neutrinos, and the
126
Xe/
127
Xe isotope ratio is an indicator of these hard neutrinos. It has been found that the formation of the
126
Xe isotope is accompanied by the emission of gamma-ray photons with a certain energy. It has been shown that the analysis of the
126
Xe/
127
Xe isotope ratio in the formed xenon gas mixture and the detection of gamma emission in
126
Xe open new capabilities of the iodine detector for the detection of solar neutrinos and make it possible to separate the important boron component of the solar spectrum.
The article reports on the current status of the Baksan Large Neutrino Telescope project and describes some selective results of the first stage of the project, a detector prototype with a liquid ...scintillator mass of 0.5 tons. The results of the second stage of the project, a prototype with liquid scintillator mass of 5 tons, and project prospects also presented.
The detectors based on the liquid scintillator (LS) monitored by an array of photo-multiplier tubes (PMT) are often used in low energy experiments such as neutrino oscillation studies and search for ...dark matter. Detectors of this kind operate in an energy range spanning from hundreds of keV to a few GeV providing a few percent resolution at energies above 1 MeV and allowing to observe fine spectral features. This article gives a brief overview of relevant physical processes and introduces a new universal simulation tool LSMC (Liquid Scintillator Monte Carlo) for simulation of LS-based detectors equipped with PMT arrays. This tool is based on the Geant4 framework and provides supplementing functionality for ease of configuration and comprehensive output. The usage of LSMC is illustrated by modeling and optimization of a compact detector prototype currently being built at Baksan Neutrino Observatory.
At the Baksan Neutrino Observatory (Institute for Nuclear Research of the Russian Academy of Sciences, Moscow) deployed in the Caucasus mountains, it is proposed to create, at a depth corresponding ...to about 4700 mwe (meter water equivalent), a large-volume neutrino detector on the basis of a liquid scintillator with a target mass of 10 kt. This article describes the current state of the first stage of the project, namely a prototype detector with a scintillator mass of 0.5 t. The design of the detector, the equipment and methods used are described.
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