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.
Modern high rates of urbanization affect the economic and social processes in cities around the world. One of the main problems in cities is the weakness of transport systems. To solve this problem, ...it is necessary to use specialized software for modeling, in consequence of the fact that there is no possibility to influence the situation in real time. The main problem in creating a transport model of cities is the lack of data on the mobility of residents. The aim of this work is to develop a method and software for automated creation of microscopic models of cities using open data. We propose the processing pipeline that consumes the open data about city population and transport infrastructure and produces routes for agents of microscopic simulation. The developed method was implemented using the Python programming language in the Zeppelin interactive environment. The software was tested on data from the city of Samara (Russia). The obtained results show acceptability of proposed method and possible ways to improve the accuracy of the model.
Buried Holocene soils and polygenetic pedolithocomplexes (PLCs) are found in the dried-off parts of the non-outflow lake depressions of the West Siberian steppe biome. Our research endeavored to ...assess the potential use of lake depression soil sand PLC as archives recording рaleoclimatic and paleoenvironmental conditions. Sargul Lake in the period of 7.5-5.8 ka cal yr BP experienced a regression stage of water accumulation. In the period about 5.8-4 ka cal yr BP the climate humidization led to the lake transgression, followed by a prolonged and steady regression stage up to 1.0 ka cal yr BP. Then a short-term transgression was recorded in 1.0-0.6 ka cal yr BP. In the Kuchuk Lake depression, a long sub-arid warm period in the middle and late Holocene (6.0-1.5 ka cal yr BP) was followed by climate humidization and relative cooling (1.5-0.9 ka cal yr BP), which at the end of Holocene (0.9-0 ka cal yr BP) was sharply replaced by climate aridization and warming. Around the same period (1.9-0 ka cal yr BP), the Bolshoi Bagan Lake depression also underwent through the lake regression.
The article discusses the problem of pedestrian accessibility of public transport stops. Research considers and analyses of existing algorithms that allow solving the localization of public transport ...stops problem in metropolis. The study suggests a formal mathematical description model of the public passenger transport system with stops and routes. A new method based on functions and operators of a genetic algorithm for optimization of public transport stops dislocation was developed. The proposed method is implemented in Python programming language and has been tested on sample data of the city of Samara.
Tracking Ultraviolet Setup (TUS) detector is a detector of ultraviolet (UV) radiation of the atmosphere in the wavelength range of 300–400 nm (near-ultraviolet) with high sensitivity (tens of photons ...emitted within the solid angle of 10
–4
sr in 0.8 μs), which operated for a year and a half aboard the
Lomonosov
satellite. The TUS telescope had a multipurpose operational program, which made it possible to detect UV flashes from the shortest ones created by extensive air showers generated by cosmic rays to long ones, up to 1 s, created by meteors. Among these various phenomena, most often are flashes from lightning strikes, both directly creating a glow and causing the development of secondary discharges in the atmosphere, in the upper atmosphere and in the ionosphere. These discharges differ in both nature and phenomenology—in particular, they have different durations and luminosities.
Two types of orbital detectors of extreme energy cosmic rays are being developed nowadays: (i) TUS and KLYPVE with reflecting optical systems (mirrors) and (ii) JEM-EUSO with high- transmittance ...Fresnel lenses. They will cover much larger areas than existing ground-based arrays and almost uniformly monitor the celestial sphere. The TUS detector is the pioneering mission developed in SINP MSU in cooperation with several Russian and foreign institutions. It has relatively small field of view (±4.5°), which corresponds to a ground area of 6.4 * 103 km2. The telescope consists of a Fresnel-type mirror-concentrator (∼ 2 m2) and a photo receiver (a matrix of 16 x 16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite, and is currently at the final stage of preflight tests. Recently, SINP MSU began the KLYPVE project to be installed on board of the Russian segment of the ISS. The optical system of this detector contains a larger primary mirror (10 m2), which allows decreasing the energy threshold. The total effective field of view will be at least ±14° to exceed the annual exposure of the existing ground-based experiments. Several configurations of the detector are being currently considered. Finally, JEM-EUSO is a wide field of view (±30°) detector. The optics is composed of two curved double-sided Fresnel lenses with 2.65 m external diameter, a precision diffractive middle lens and a pupil. The ultraviolet photons are focused onto the focal surface, which consists of nearly 5000 multi-anode photomultipliers. It is developed by a large international collaboration. All three orbital detectors have multi-purpose character due to continuous monitoring of various atmospheric phenomena. The present status of development of the TUS and KLYPVE missions is reported, and a brief comparison of the projects with JEM-EUSO is given.
The current status of the KLYPVE orbital detector of ultrahigh energy cosmic rays, which is scheduled to be deployed on board the Russian module of the International Space Station, is discussed. The ...main focus is on describing possible optical systems for the instrument.
JEM-EUSO is an international program for the development of space-based Ultra-High Energy Cosmic Ray observatories. The program consists of a series of missions which are either under development or ...in the data analysis phase. All instruments are based on a wide-field-of-view telescope, which operates in the near-UV range, designed to detect the fluorescence light emitted by extensive air showers in the atmosphere. We describe the simulation software ESAF in the framework of the JEM-EUSO program and explain the physical assumptions used. We present here the implementation of the JEM-EUSO, POEMMA, K-EUSO, TUS, Mini-EUSO, EUSO-SPB1 and EUSO-TA configurations in ESAF. For the first time ESAF simulation outputs are compared with experimental data.
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