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.
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.
Analysis of Anomalous Events in TUS Data Lavrova, M. V.; Blinov, A. V.; Grinyuk, A. A. ...
Physics of atomic nuclei,
08/2023, Letnik:
86, Številka:
4
Journal Article
Recenzirano
The main goal of the TUS experiment was to search for and study extremely high-energy cosmic rays with energies
EeV. The TUS detector registered a number of unusual events, the origin of which is ...unclear. The analysis of not similar to EAS and unique anomalous events is the subject of the study presented in this paper.
The TUS experiment is aimed to study the energy spectrum and arrival direction of Ultra High Energy Cosmic Rays at
E
∼ 100 EeV from the space orbit by measuring the fluorescence radiation of the ...Extensive Atmospheric Shower in the atmosphere. It is the first orbital telescope aimed for such measurements and is taking data since April 28, 2016. During the first turns of operation ∼20% PMTs were broken due to the HV tuning system failure. For the same reason, the properties of the remaining PMTs are changed. Relative calibration of PMT gains in flight was done and presented based on analyzing TUS background data itself. A reconstruction of EAS arrival directions is done using the relative calibration coefficients.
Abstract
The work is based on 40 years of research by the authors of the project of electromagnetic fields of the infra-low-frequency range (ILF) and meteorological data at the physical experimental ...range of VlSU. The creation of a system for monitoring the electric and geomagnetic fields of the surface layer of the atmosphere in a network of stations spaced apart in space with a reliable assessment of the impact of global geophysical processes opens on this basis the possibility of predicting natural and man-made processes, analyzing seismic activity and the relationship of atmospheric electricity with the dynamics of meteorological processes. Long-term observations of electric and geomagnetic fields in the HF range have convinced the authors of the unique properties of EMPZ, bearing signs of many geophysical processes, including the processes of preparation of large seismic events. The catalogs of detected types of precursor anomalies in the electric field of the surface layer of the atmosphere are presented. Observed mainly anomaly types: seismogravitational oscillations; a sharp decrease in the field level up to a change in its sign; an increase in the level of the electric field. These anomalies (precursors) are observed both a few hours before the onset of an earthquake and a day, and seismic gravity fluctuations persist even after the moment of the earthquake. The developed catalogs of the precursors of strong earthquakes make it possible to analyze the pattern of changes in the character of the electric field in the surface layer of the atmosphere during the periods of preparation of seismic events.
New complex RuL(Dmdcbp)
2
PF
6
(
I
) is synthesized by the consecutive reactions of Ru-
p
-cymene
2
Cl
4
with 3,3',5,5'-tetramethyl-1,1'-biphenyl-4,4'-bipyrazole (L) and ...4,4'-dicarboxy-2,2'-bipyridine in a methanol–chloroform medium. The composition of complex
I
is confirmed by NMR and elemental analysis, and the optical and luminescence properties of the complex are studied. Ligand L is characterized for the first time by X-ray diffraction (CIF file CCDC no. 2118676). Quantum chemical calculations in terms of the density functional theory are performed for the interpretation of the absorption and emission spectra. Complex
I
is promising for using as a photosensitizer.
Study of Anomalous Events in the TUS Experiment Lavrova, M. V.; Blinov, A. V.; Grinyuk, A. A. ...
Bulletin of the Russian Academy of Sciences. Physics,
07/2023, Letnik:
87, Številka:
7
Journal Article
Recenzirano
The results of the TUS experiment on search and study ultra high-energy cosmic rays with energies
E
> 70 EeV are analyzed. The TUS detector registered several unusual events of the unclear origin. ...The analysis of not similar to EAS and unique anomalous events is the subject of the study presented in this paper.
The “Lomonosov” space project is lead by Lomonosov Moscow State University in collaboration with the following key partners: Joint Institute for Nuclear Research, Russia, University of California, ...Los Angeles (USA), University of Pueblo (Mexico), Sungkyunkwan University (Republic of Korea) and with Russian space industry organizations to study some of extreme phenomena in space related to astrophysics, astroparticle physics, space physics, and space biology. The primary goals of this experiment are to study:
Ultra-high energy cosmic rays (UHECR) in the energy range of the Greizen-Zatsepin-Kuzmin (GZK) cutoff;
Ultraviolet (UV) transient luminous events in the upper atmosphere;
Multi-wavelength study of gamma-ray bursts in visible, UV, gamma, and X-rays;
Energetic trapped and precipitated radiation (electrons and protons) at low-Earth orbit (LEO) in connection with global geomagnetic disturbances;
Multicomponent radiation doses along the orbit of spacecraft under different geomagnetic conditions and testing of space segments of optical observations of space-debris and other space objects;
Instrumental vestibular-sensor conflict of zero-gravity phenomena during space flight.
This paper is directed towards the general description of both scientific goals of the project and scientific equipment on board the satellite. The following papers of this issue are devoted to detailed descriptions of scientific instruments.
High-energy cosmic-ray research via the detection of Cherenkov radiation from extensive air showers was begun in the Tunka valley (50 km to the west from the southern extremity of Lake Baikal) in the ...early 1990s. A series of large arrays combined into the TAIGA (Tunka Advanced Instrument for cosmic-ray physics and Gamma Astronomy) astrophysical facility and designed to study gamma rays and charged cosmic rays have been created in the elapsed time. Descriptions of the facility arrays and the main results obtained while investigating high-energy cosmic rays are presented. Plans for a further development of the astrophysical facility are discussed.
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