Abstract
This paper presents the gamma-ray detection performance of the newly developed MAPD-3NM-II type SiPM sensor array (4
$$\times$$
×
4) with
$$\hbox {LaBr}_3$$
LaBr
3
(Ce) scintillator. The ...gamma-ray spectra of various sources have been measured in the energy range from 26 keV up to 1332 keV. The newly developed array based on MAPD-3NM-II sensors proved
$$\sim$$
∼
22% enhancement in energy resolution in comparison to the former MAPD-3NM-I based array. The energy resolution of 662 keV gamma-rays measured by MAPD-3NM-II was 3.3% while clearly surpassing 4.25% resolution of MAPD-3NM-I predecessor. The enhancement is related to the high PDE of the new MAPD-3NM-II. Obtained results show that the new MAPD-3NM-II demonstrated good energy resolution and linearity in the studied energy region. The energy resolution of the new detector developed based on MAPD-3NM-II was better than all previous products of MAPD.
The paper contains the proof of the existence of two different positive solutions of the problem
involving convex and concave nonlinearities, the parameter
, and the variables
. The coefficient ...matrix
satisfies the nonuniform ellipticity condition
in a bounded domain
,
,
. To achieve the goal, the authors consider the conditions on the range of nonlinearity exponents
and
(or
and the additional condition
) and
for a sufficiently small
; positive weight functions
,
belong to the corresponding Muckenhoupt classes in the metric of
-dimensional Euclidean space and also the balance condition of Chanillo–Wheeden type holds.
The aim of the work is to develop a mechanism for cross-border carbon regulation for countries importing products to the EU, which will equally allow importing countries to fulfill the conditions of ...the Carbon Border Adjustment Mechanism (CBAM), encourage manufacturers to reduce CO2 emissions, and also provide importing countries with opportunities to replenish their budget by introducing paid emission quotas greenhouse gases. The work makes a significant contribution to stimulating the reduction of CO2 emissions by producers due to the proposed tax mechanism and preventing the leakage of greenhouse gases on the territory of third countries according to the CBAM policy. The EU evaluates double taxation, so if a carbon tax has been withdrawn in the territory of the exporting country, then such a tax will not be levied again in the EU. All this involves stimulating exporting countries by creating their own taxation systems, which will have international qualifications and be recognized by countries around the world. When choosing a taxation mechanism, it is important to choose the specifics for visiting group gases. The study was conducted on the basis of methods of comparison, modeling, analysis and deduction.
In this work cubic phase, silicon carbide nano-powders were irradiated at the high-flux pulsed reactor IBR–2 (Dubna, Russia). The 3C–SiC powder was irradiated with neutron doses up to 1015 n/cm2. The ...irradiated samples were then analyzed using X-ray diffraction, Raman spectroscopy, Positron annihilation spectroscopy, and Fourier Transform Infrared Spectroscopy. The XRD analysis showed a slight decrease in the lattice parameters with the increase in neutron fluences. The results obtained from positron annihilation measurements were compared to the theoretical calculations, to recognizing the type of structural defect in the samples. A positron lifetime component 355 ps associated with the calculated values for clusters containing of 13–21 vacancies was identified. The concentration of these defects was estimated to be in the region of 5 ppm, and was very similar to the one identified on the unirradiated sample. The results also indicate high irradiation resistivity of the 3C–SiC after irradiation.
•Nano silicon carbide was irradiated fast neutron flux up to 1015 n/cm² and energy of neutron flux E≥1 MeV at room temperature.•A positron lifetime component 355 ps associated with the calculated values for clusters containing of 13 to 21 vacancies was identified.•At small fluences up to 1.3×1013 n/cm² the lattice parameters decrease from 4.3571 Å to 4.3527 Å is observed.
In this paper we present the results of studies into the frequency and temperature dependences of the dielectric loss tangent and the real and imaginary parts of the permittivity in MnGaInSe
4
single ...crystals in an alternating electric field. The main type of dielectric losses in MnGaInSe
4
single crystals in the frequency range of 8 × 10
3
–3 × 10
5
Hz is established to be electrical conductivity losses, while the conductivity is characterized by the zone-hopping mechanism. The activation energies of current carriers of single crystals are determined. The real and imaginary parts of the permittivity are found to undergo significant dispersion, which is of a relaxation nature.
Abstract
In the presented work, the parameters of a new MAPD-3NM-II photodiode with buried pixel structure manufactured in cooperation with Zecotek Company are investigated. The photon detection ...efficiency, gain, capacitance and gamma-ray detection performance of photodiodes are studied. The SPECTRIG MAPD is used to measure the parameters of the MAPD-3NM-II and scintillation detector based on it. The obtained results show that the newly developed MAPD-3NM-II photodiode outperforms its counterparts in most parameters and it can be successfully applied in space application, medicine, high-energy physics and security.
The frequency and temperature dependences of the ac electrical conductivity of the MnGaInSe
4
single crystals have been investigated. It has been established that, in the temperature range of ...295.5–360 K at frequencies of 2 × 10
4
–10
6
Hz, the electrical conductivity obeys the regularity σ ~
f
S
(0.1 ≤
S
≤ 1.0). It is shown that the frequency dependence of the electrical conductivity for the MnGaInSe
4
single crystal can be explained using a multiplet model and the conductivity in these single crystals is implemented via the band-hopping mechanism. The activation energies have been determined on the basis of dependences logσ ~ 10
3
/
T
.
Radon is one of the main potential sources of background radiation for any rare event experiments like neutrinoless double beta decay or dark matter experiments. The Radon Trapping Facility (RTF) ...installed in 2004 at the Modane Underground Laboratory (LSM) has been running for nine years providing radon-purified air at a level of 10 mBq m−3 for several experiments. The radon suppression principle is based on a radon physical adsorption using cooled compressed air at −55 °C pumped through a column filled with the K48 activated charcoal. After disassembling of the RTF, the 2.6 m high charcoal column has been divided into several layers in order to study with different techniques the dynamic adsorption coefficient (the K-factor) as a function of the depth and the radon spatial trapping profile by measuring the 210Pb activity. It has been demonstrated that after almost a decade of running, the K-factor of the activated charcoal remains constant except for the first few cm of the column. Furthermore, it has been demonstrated that the mass activity of 210Pb as a function of the depth of the charcoal column exhibits an exponential decay profile. The radon mean retention time τR of (47.6 1.2) days and the radon mean free path of (28.9 0.4) cm have been derived and found to be consistent at 1 with the ones obtained from the K-factor study, i.e. from a total independent measurement. The radon suppression factor of the RTF of 6790 − 1720 + 2370 has been also estimated with a value consistent at 2 with the suppression factor measured during the RTF operation. Thus, this study has proven the capacity of the RTF to purify the LSM air from radon by more than three orders of magnitude during nine years of operation.
Introduction There are not enough published studies on the impact of early isolated triceps lengthening operations in hemiparesis on the state of motor characteristics and on the development of ...orthopedic complications in children with GMFCS II. Purpose Analyze motor locomotion in children with spastic hemiplegia who had not previously been operated on and those who had undergone isolated surgical lengthening of the triceps at an early age. Material and methods Four groups of children with spastic hemiplegia according to Rodda et Graham types: I) type 2a gait (4 children), II) type 3 (3 children), III) type 4 (7 children), IV) type 4 with previous triceps lengthening (9 children). Results The features revealed in gait types 2a, 3 and 4 in the sagittal plane correspond to the characteristic and previously described features. In all groups, asymmetric rotational movements of the pelvis and tilt asymmetry in the frontal plane were observed. In the group of early isolated tricep lengthening, a decrease in the moment of force by pushing with the foot at the end of the single-support phase was revealed, in combination with an increase in the moment of forces of knee joint extension in the single-support phase. Discussion Early isolated triceps lengthening that weakens its function leads to a compensatory increase in the work of the knee extensors which is similar to the mechanism to of iatrogenic crouch gait, but does not result in a complete loss of walking function in the conditions of a contralateral healthy limb. Conclusions Movement pathology is present in all three measurement planes in gait types 2a, 3, 4 according to the Rodda et Graham classification. The most pronounced deviations were found in gait type 3. The rotational turn of the pelvis is an initially compensatory mechanism due to intratorsion femur deformity. Isolated triceps lengthening surgeries performed at an early age lead to reduced plantar push strength, increased compensatory work of the knee extensors, and probably do not prevent the orthopedic pathology found in Rodda et Graham's gait type 4.
Abstract
DANSS is a one cubic meter plastic scintillator detector
with a primary goal of sterile neutrino searches at a commercial
nuclear reactor. Due to its highly advantageous location, fine
...segmentation and ability to change the distance to the neutrino
production origin, DANSS is ahead of many similar experiments around
the world in terms of the counting rate, signal to background ratio
and sterile neutrino exclusion regions. Yet a moderate energy
resolution of the detector prevents further progress in the physics
program. The main challenge of the planned upgrade is to achieve an
energy resolution of 12% at 1 MeV. The new design of the main
sensitive element — the plastic scintillation strip — is the
most important step forward. The strip prototypes were manufactured
and tested at the pion beam of the PNPI synchrocyclotron. More than
twice higher light output together with fairly flat detector
response uniformity, longitudinal timing information and other
optimizations will help to reach the upgrade goal. This paper
discusses the drawbacks of the current strip version, outlines the
new features of the proposed upgrade, describes the beam test
procedure and presents the test results reflecting the advantages of
the new strip design in comparison with the current version.
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