In this work, the laser-based synthesis and characterization of Mo nanoparticles formed using Kr–F laser pulse photolysis of the vapor of Mo(CO)
6
diluted by argon at room temperature were carried ...out. The time-resolved laser-induced incandescence (Ti–Re LII) technique was applied for the sizing of aerosolized particle inside of the quartz reactor. The samples of synthesized Mo nanoparticles were analyzed by transmission electron microscopy (TEM). The particle sizes measured by Ti–Re LII were found to be in a range of 3–13 nm in dependence on excimer Kr–F laser pulse energy and number of pulses. The temperature time behavior of laser-heated nanoparticles was observed by two-color pyrometry at the wavelengths 400 and 610 nm. The maximum particle temperature attained at high laser fluences was attributed to evaporation temperature and was found to be around 3,900 K unlike the boiling temperature of bulk Mo (4,800 K). The probable influence of nanoparticle properties on the results of Ti–Re LII sizing and nanoparticle oxidation in air on the results of TEM measurements is discussed.
Neutrinoless double-
β
decay of
76
Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase ...the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in
76
Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the
Gerda
setup. The measured resolutions at the
Q
-value for double-
β
decay of
76
Ge (
Q
β
β
= 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (
Gerda
) experiment and an accumulated exposure of 8.5 kg
·
year, the background index after analysis cuts is measured to be
4
.
9
-
3.4
+
7.3
×
10
-
4
counts
/
(
keV
·
kg
·
year
)
around
Q
β
β
. This work confirms the feasibility of IC detectors for the next-generation experiment
Legend
.
Constructing a large-volume detector filled with 10 kt of liquid scintillator is envisaged at the Baksan Neutrino Observatory in the Caucasus. This is aimed at detecting fluxes of natural neutrinos ...with energies up to 100 MeV. The predicted fluxes of such neutrinos and the response of the proposed detector are discussed. This facility is conceived as an integral part of the worldwide net of neutrino detectors aimed at measuring the natural neutrino fluxes.
Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron ...capture of Formula omittedAr has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (Gerda) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of Formula omittedAr was established: Formula omitted 3.6 Formula omitted 10 Formula omitted years at 90% CI.
Abstract Neutrinoless double- $$\beta $$ β decay of $$^{76}$$ 76 Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future ...experiments it is important to increase the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in $$^{76}$$ 76 Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the Gerda setup. The measured resolutions at the Q-value for double- $$\beta $$ β decay of $$^{76}$$ 76 Ge ( $$Q_{\beta \beta }$$ Q β β = 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (Gerda) experiment and an accumulated exposure of 8.5 kg $$\cdot $$ · year, the background index after analysis cuts is measured to be $$4.9^{+7.3}_{-3.4}\times 10^{-4} \ \text {counts}/(\text {keV} \cdot \text {kg} \cdot \text {year})$$ 4 . 9 - 3.4 + 7.3 × 10 - 4 counts / ( keV · kg · year ) around $$Q_{\beta \beta }$$ Q β β . This work confirms the feasibility of IC detectors for the next-generation experiment Legend.
Because of a high energy of the neutrinoless double-beta decay (0v2beta) of the isotope sup.150Nd and a high value of the daughter-nucleus charge Zf, sup.150Nd is one of the most promising isotopes ...for 0v2beta-decay searches. A sup.150Nd-containing detector on the basis of a liquid organic scintillator permits employing large isotope masses. Requirements on the radiation purity of the neodymium sample used are determined. The possible design of a large-scale detector of this type and expected results are considered.
The Gerda experiment at Lngs of INFN is equipped with an active muon veto. The main part of the system is a water Cherenkov veto with 66 PMTs in the water tank surrounding the Gerda cryostat. The ...muon flux recorded by this veto shows a seasonal modulation. Two causes have been identified: (i) secondary muons from the Cngs neutrino beam (2.2%) and (ii) a temperature modulation of the atmosphere (1.4%). A mean cosmic muon rate of Iμ0=(3.477±0.002stat±0.067sys)×10−4/(s · m2) was found in good agreement with other experiments at Lngs. Combining the present result with those from previous experiments at Lngs the effective temperature coefficient αT,Lngs is determined to 0.93 ± 0.03. A fit of the temperature coefficients measured at various underground sites yields a kaon to pion ratio rK/π of 0.10 ± 0.03.
Neutrinoless double-
decay of
Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase the ...mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in
Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the Gerda setup. The measured resolutions at the
-value for double-
decay of
Ge (
= 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (Gerda) experiment and an accumulated exposure of 8.5 kg
year, the background index after analysis cuts is measured to be
around
. This work confirms the feasibility of IC detectors for the next-generation experiment Legend.
Neutrinoless double-
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76
Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in
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76
Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the
Gerda
setup. The measured resolutions at the
Q
-value for double-
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β
decay of
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76
Ge (
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β
β
= 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (
Gerda
) experiment and an accumulated exposure of 8.5 kg
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year, the background index after analysis cuts is measured to be
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\begin{document}$$4.9^{+7.3}_{-3.4}\times 10^{-4} \ \text {counts}/(\text {keV} \cdot \text {kg} \cdot \text {year})$$\end{document}
4
.
9
-
3.4
+
7.3
×
10
-
4
counts
/
(
keV
·
kg
·
year
)
around
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Q
β
β
. This work confirms the feasibility of IC detectors for the next-generation experiment
Legend
.
Display omitted
•Carbon-encapsulated molybdenum nanoparticles were synthesized at room temperature.•Different hydrocarbons were used as carbon source for shell formation.•Increase of hydrocarbon mole ...ratio resulted in decrease of Mo-based nanoparticle cores.•Increase of laser pulses number resulted in increase of Mo content in CEMNPs.•Carbon shells prevented Mo nanoparticles from aggregation.
Carbon-encapsulated molybdenum nanoparticles were synthesized by laser-assisted photolysis of gaseous precursors. In the proposed method, gas mixtures containing various hydrocarbons and molybdenum hexacarbonyl vapor diluted in argon were irradiated with a nanosecond pulsed UV laser at room temperature. Particle samples were analyzed by transmission electron microscopy (TEM), electron microdiffraction (EMD), energy-dispersive X-ray spectroscopy (EDS), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) techniques to observe the morphology and composition of the Mo/C nanoparticles. The influence of the type of hydrocarbon, its mole fraction, and the number of UV laser pulses on the resulting nanoparticles was investigated. The nanoparticles were heavily aggregated and consisted of Mo-based cores surrounded by carbon. The type of hydrocarbon did not have any visible effects on the nanoparticle structure and the size of the Mo-based cores or aggregates. Increasing the hydrocarbon mole fraction in the precursor mixture led to an increase in the carbon content and decrease of the Mo-based core size. Increasing the number of UV laser pulses led to larger Mo cores.
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