The origin and nature of extreme energy cosmic rays (EECRs), which have energies above the
5
⋅
10
19
eV
—the Greisen-Zatsepin-Kuzmin (GZK) energy limit, is one of the most interesting and complicated ...problems in modern cosmic-ray physics. Existing ground-based detectors have helped to obtain remarkable results in studying cosmic rays before and after the GZK limit, but have also produced some contradictions in our understanding of cosmic ray mass composition. Moreover, each of these detectors covers only a part of the celestial sphere, which poses problems for studying the arrival directions of EECRs and identifying their sources. As a new generation of EECR space detectors, TUS (Tracking Ultraviolet Set-up), KLYPVE and JEM-EUSO, are intended to study the most energetic cosmic-ray particles, providing larger, uniform exposures of the entire celestial sphere. The TUS detector, launched on board the Lomonosov satellite on April 28, 2016 from Vostochny Cosmodrome in Russia, is the first of these. It employs a single-mirror optical system and a photomultiplier tube matrix as a photo-detector and will test the fluorescent method of measuring EECRs from space. Utilizing the Earth’s atmosphere as a huge calorimeter, it is expected to detect EECRs with energies above
10
20
eV
.
It will also be able to register slower atmospheric transient events: atmospheric fluorescence in electrical discharges of various types including precipitating electrons escaping the magnetosphere and from the radiation of meteors passing through the atmosphere. We describe the design of the TUS detector and present results of different ground-based tests and simulations.
TUS (Tracking Ultraviolet Set-up) is the world's first orbital detector of ultra-high-energy cosmic rays (UHECRs). It was launched into orbit on 28th April 2016 as a part of the scientific payload of ...the Lomonosov satellite. The main aim of the mission was to test the technique of measuring the ultraviolet fluorescence and Cherenkov radiation of extensive air showers generated by primary cosmic rays with energies above ∼100 EeV in the Earth atmosphere from space. During its operation for 1.5 years, TUS registered almost 80,000 events with a few of them satisfying conditions anticipated for extensive air showers (EASs) initiated by UHECRs. Here we discuss an event registered on 3rd October 2016. The event was measured in perfect observation conditions as an ultraviolet track in the nocturnal atmosphere of the Earth, with the kinematics and the light curve similar to those expected from an EAS. A reconstruction of parameters of a primary particle gave the zenith angle around 44ˆ but an extreme energy not compatible with the cosmic ray energy spectrum obtained with ground-based experiments. We discuss in details all conditions of registering the event, explain the reconstruction procedure and its limitations and comment on possible sources of the signal, both of anthropogenic and astrophysical origin. We believe this detection represents a significant milestone in the space-based observation of UHECRs because it proves the capability of an orbital telescope to detect light signals with the apparent motion and light shape similar to what are expected from EASs. This is important for the on-going development of the future missions KLYPVE-EUSO and POEMMA, aimed for studying UHECRs from space.
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•Evolution of Graphene/Ni system due to intercalation with Fe and Si is studied.•Graphene strongly interacts with the topmost atoms of the intercalated fcc Fe film.•The in-plane ...ferromagnetic ordering of the film arises after intercalation of 5ML Fe.•Fe-Si solid solution and Fe3Si surface silicide are formed after intercalation of Si.•The capping graphene layer is weakly electronically coupled to the silicide phase.
A new method for synthesis of graphene-protected iron silicides has been tested, which consists in formation of graphene on Ni(111) followed by two-step intercalation of the system with Fe and Si. Characterization of the samples was performed in situ by low-energy electron diffraction, angular-resolved photoelectron spectroscopy, core-level photoelectron spectroscopy with synchrotron radiation and magnetic linear dichroism in photoemission of Fe 3p electrons. It is shown, that at 400°C the intercalation of graphene/Ni(111) with iron occurs in a range up to 14ML. The graphene layer strongly interacts with the topmost Fe atoms and stabilizes the fcc structure of the film. The in-plane ferromagnetic ordering of the film has a threshold nature and arises after the intercalation of 5ML Fe due to the thickness-driven spin reorientation transition. Subsequent intercalation of graphene/Fe/Ni(111) with Si leads to the formation of the inhomogeneous system consisted of intercalated and nonintercalated areas. The intercalated islands coalesce at 2ML Si when a Fe-Si solid solution covered with the Fe3Si surface silicide is formed. The Fe3Si silicide is ferromagnetic and has an ordered (√3×√3)R30° structure. The graphene layer is weakly electronically coupled to the silicide phase keeping its remarkable properties ready for use.
TUS (Tracking Ultraviolet Set-up), the first orbital detector of extreme energy cosmic rays (EECRs), those with energies above 50 EeV, was launched into orbit on April 28, 2016, as a part of the ...Lomonosov satellite scientific payload. The main aim of the mission is to test a technique of registering fluorescent and Cherenkov radiation of extensive air showers generated by EECRs in the atmosphere with a space telescope. We present preliminary results of its operation in a mode dedicated to registering extensive air showers in the period from August 16, 2016, to November 4, 2016. No EECRs have been conclusively identified in the data yet, but the diversity of ultraviolet emission in the atmosphere was found to be unexpectedly rich. We discuss typical examples of data obtained with TUS and their possible origin. The data is important for obtaining more accurate estimates of the nocturnal ultraviolet glow of the atmosphere, necessary for successful development of more advanced orbital EECR detectors including those of the KLYPVE (K-EUSO) and JEM-EUSO missions.
Some results of studies of cosmic rays obtained during the NUCLEON space experiment in 2015–2017 are presented. This experiment was intended for direct measurements of the energy spectra and chemical ...composition of cosmic rays (
Z
= 1−30) in the energy range 2–500 TeV. Results presented include energy spectra for various abundant nuclei measured using the new Kinematic Lightweight Energy Meter (KLEM). The primary energies are established using the spatial densities of secondary particles produced in inelastic interactions with a carbon target.
The aim
of the study was to investigate vegetative maintenance of the activity and state of systemic hemodynamics in patients with a first time, non-traumatic epileptic seizure during a tilt table ...test (TTT).
Materials and methods
. TTT was performed in 42 patients with absence of seizures and 78 patients having experienced unprovoked seizures. A control group included 70 patients with non-epileptic seizures with transient loss of consciousness (TLC), defined as syncope. The control group included 38 people without episodes of loss of consciousness in their medical history. The parameters of hemodynamics and heart rate variability (HRV) were investigated at all stages of the test.
Results
. In patients with absence of seizures, initial sympathicotonia was recorded along with a decrease in ergotropic activation in orthostasis. In patients with unprovoked seizures, a hypersympathicotonic response to the orthostatic test was detected in combination with impaired vagal overshoot in the clinostatic phase of the test. In patients with TLC, evidence of vegetative insufficiency in the vertical position was identified, with the indicators going back to the background values in the horizontal position.
Conclusion
. The revealed features of vegetative regulation in patients with absence of seizures and unprovoked seizures will allow to differentiate the mechanism of the first-time epileptic seizure more accurately.
•Formation of Co2FeSi alloy films on the CaF2/Si(111) substrate is studied in situ.•5nm CaF2 layer inhibits the diffusion of the alloy components into a substrate.•Annealing of deposited Co/Fe/Si ...layers at 200°C leads to formation of the alloy.•The alloy is characterized by the mode with energy of 99.01eV in Si 2p spectra.•2nm Co2FeSi film is ferromagnetic and stable at temperatures below 450°C.
Ultrathin (∼2nm) films of Co2FeSi ferromagnetic alloy were formed on silicon by solid-phase epitaxy and studied in situ. Experiments were carried out in an ultrahigh vacuum (UHV) using substrates of Si(111) single crystals covered with a 5nm thick CaF2 barrier layer. The elemental and phase composition as well as the magnetic properties of the synthesized films were analyzed by photoelectron spectroscopy using synchrotron radiation and by magnetic linear dichroism in photoemission of Fe 3p and Co 3p electrons. The study shows that the synthesis of the Co2FeSi ferromagnetic alloy occurs in the temperature range of 200–400°C. At higher temperatures, the films become island-like and lose their ferromagnetic properties, as the CaF2 barrier layer is unable to prevent a mass transfer between the film and the Si substrate, which violates the stoichiometry of the alloy.
A Mathematical Wave Analysis was conducted to study the frequency-temporal characteristics of sleep spindles in idiopathic generalized epilepsy (IGE) with variable phenotypes in adults. In resistant ...generalized tonic-clonic seizures (GTCS), the maximum duration of the stationary part of the sleep spindle in the 10–12Hz frequency band in the frontal and parietal regions was greater with Juvenile Absence Epilepsy compared with Juvenile Myoclonic Epilepsy and IGE with isolated GTCS. In patients with GTCS remission who took antiepileptic drugs (AED’s) in the anamnesis, the frequency-time characteristics of the sleep spindle were not different. In the entire group, the maximum duration of the stationary part of the sleep spindles in patients with IGE with a variable phenotype receiving AED’s was significantly less than in patients who stopped receiving AED’s. The revealed differences in the duration of the stationary part of the sleep spindles are due to various pathogenetic mechanisms underlying the different types of generalized seizures in adults, and can be used to refine the subtype of the IGE and evaluate the efficacy of the AED’s.
—The fruits of
Trapa natans
L. s.l. (Trapaceae) (disappeared from the territory of Saratov oblast), collected in floodplain lakes of the Khoper River at the territory of Voronezh oblast ...(Novokhoporskii district), were sown in autumn 2019 and spring 2020 into the Khoper and Volga rivers on the territory of Saratov oblast. In autumn 2020, germinated rosettes of water caltrop were noted in 17 sowing places; moreover, there were fewer germinated rosettes than the number of fruits sown in most of these places. Only in three artificial plantings was the number of rosettes equal to or more than the number of fruits sown. According to morphometric parameters of the vegetative sphere, five artificial plantings (nos. 6, 7, 9, 15, 21) from the Khoper River are close to the donor populations; by potential and real seed productivity, only two artificial plantings (nos. 7 and 9) from the Khoper River. Reintroduction of
T. natans
is more promising in the Khoper River, while reintroduction is complicated in the Volga River (at least in the seeding region) due to sharp changes in the water level during the season.
As part of the preparation of the TAIGA gamma ray observatory (Republic of Buryatia, Russian Federation) and the TUS space experiment on the Mikhailo Lomonosov satellite, 1400 PMTs of XP1911 type, ...1020 PMTs of XP1911/UV type, and 290 PMTs of R1463 type were tested for their main and additional specifications (nominal (operating) voltage, dark current at nominal voltage, quantum efficiency of the photocathode at a wavelength of 480 nm, cathode chamber resistivity, and quality parameters of the dynode system). The number of PMTs that did not meet the selection criteria is 3.9% for XP1911, 15.8% for XP1911/UV, and 4.8% for R1463 of the corresponding number of PMTs of this type. The parameters of 856 PMTs of XP1911/UV type, which successfully passed the selection criteria and turned out to be ready for use in the TAIGA experiment, were compared with the corresponding parameters of the new 1250 PMTs of R7877 type (Hamamatsu) previously measured for the ATLAS hadron scintillation calorimeter at the LHC (CERN, Geneva, Switzerland).
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