A search for resonant absorption of solar axions by
169
Tm
nuclei was carried out. A newly developed approach involving low-background cryogenic bolometer based on
Tm
3
Al
5
O
12
crystal was used ...that allowed for significant improvement of sensitivity in comparison with previous
169
Tm
based experiments. The measurements performed with 8.18 g crystal during 6.6 days exposure yielded the following limits on axion couplings:
|
g
A
γ
(
g
AN
0
+
g
AN
3
)
≤
1.44
×
10
-
14
GeV
-
1
and
|
g
Ae
(
g
AN
0
+
g
AN
3
)
≤
2.81
×
10
-
16
.
The resonant excitation of the
83
Kr first excited nuclear level (
E
= 9.4 keV) by solar axions whose fluxes depend on the axion–electron coupling constant
g
Ae
is sought. The γ- and X-ray photons ...and the conversion and Auger electrons from the excited-level relaxation are detected with a gas proportional counter of a low-background detector in the underground Baksan Neutrino Observatory (Institute for Nuclear Research, Russian Academy of Sciences). As a result, a new constraint
≤ 1.50 × 10
–17
(90% C.L.) has been obtained for the axion–electron and axion–nucleon coupling constants, which corresponds to new constraints on the axion mass
m
A
≤ 320 eV and
m
A
≤ 4.6 eV in the KSVZ and DFSZ axion models, respectively.
The 169Tm nuclide has first nuclear level at 8.41 keV with magnetic type transition to the ground state and, therefore, can be used as a target nucleus for the search of resonant absorption of solar ...axions. We plan to use a Tm-containing crystal of a garnet family Tm3Al5O12 as a bolometric detector in order to search for the resonant absorption of solar axions. With this perspective in mind, a sample of the Tm3Al5O12 crystal was grown and tested for its bolometric and optical properties. Measurements of chemical and radioactive contaminations were performed as well. In this paper we present the test results and estimate the requirements for a future low-background experimental setup.
Axions with an energy of 8.4 keV emitted in the
М
1 transition in
169
Tm nuclei in the Sun are sought in the
→
169
Tm* →
(8.4 keV) reaction of resonant absorption by
169
Tm nuclei on the Earth using ...a
thulium garnet crystal as a bolometric detector. The flux of monochromatic 8.4‑keV axions has been calculated. New constraints on the axion–nucleon coupling constants have been obtained and, as a result, new upper bounds on the axion mass
eV and
eV have been obtained at 90% C.L. in the KSVZ and DFSZ models, respectively.
Resonance excitation of the
83
Kr first nuclear level (
E
= 9.4 keV) by solar axions formed via the Primakoff mechanism is sought. The γ- and X-ray photons and the conversion and Auger electrons ...arising from the excited-level relaxation are detected with a gas proportional counter of a low-background detector in the underground Baksan Neutrino Observatory. The following experimental constraint is obtained for the product of the axion–photon coupling constant and the axion mass:|
g
A
γ
×
m
A
| ≤ 6.3 × 10
-17
In the framework of the hadronic-axion model, this corresponds to a new axion-mass constraint of
m
A
≤ 12.7 eV at 95% C.L.
—
A 4π β spectrometer consists of two Si(Li) detectors with a sensitive region that is more than 8-mm thick. Using this total-absorption spectrometer it is possible to make a direct measurement of β ...spectra without correcting the response function for the electron backscattering from the crystal surface. The β spectra of transitions to the excited states of daughter nuclei have been measured using an additional 3'' BGO detector of γ rays, which is connected in coincidence with the pair of Si(Li) detectors.
4π spectrometer of β-decay electrons with Si(Li)-detectors Alekseev, I.E.; Bakhlanov, S.V.; Bazlov, N.V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
June 2023, Letnik:
1051
Journal Article
Recenzirano
We present a description of the originally developed β-spectrometer consisting of two Si(Li)-detectors with sensitive area thickness above 8 mm and 4π-geometry. The full absorption spectrometer ...allows for direct measurements of β-spectra, disregarding the corrections to response function induced by the electron backscattering from the crystal surface. In case of β-spectra of transitions to the excited state of the daughter isotope additional 3″ BGO-detector is used in order to detect the γ-quanta in coincidence with the pair of Si(Li)-spectrometers.
Operation of a model of a compact neutron source that can be used to calibrate dark-matter and electron-antineutrino detectors and to determine their response functions is demonstrated. The ...calibration neutron source in question is a combination of the
Cf radionuclide, which undergoes spontaneous fission, producing neutrons, and an original silicon semiconductor detector. The latter provides a time reference for the neutron-emission instant by recording signals from fission fragments.
We present new constraints on sub-GeV dark-matter particles scattering off electrons based on 6780.0 kg d of data collected with the DarkSide-50 dual-phase argon time projection chamber. This ...analysis uses electroluminescence signals due to ionized electrons extracted from the liquid argon target. The detector has a very high trigger probability for these signals, allowing for an analysis threshold of three extracted electrons, or approximately 0.05 keVee. We calculate the expected recoil spectra for dark matter-electron scattering in argon and, under the assumption of momentum-independent scattering, improve upon existing limits from XENON10 for dark-matter particles with masses between 30 and 100 MeV/c^{2}.
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