This paper presents an investigation into structure and magnetic properties of Fe–50%Ni permalloy bulk samples manufactured from the powder of the same chemical composition by selective laser melting ...(SLM). The relations of microstructure, heat treatment parameters, maximum relative permeability (μmax) and coercivity (Hc) were established. Fine fcc crystallographic structure with elongated grains in building direction was observed. In as-built state the mode angle of misorientation which characterizes the degree of internal stresses was close to 0.5° that was near the lowest reliably determined misorientation. After heat treatment it was shifted to the bigger angles at the region of 1°, meanwhile the microhardness lowered from 275 HV down to 190 HV after annealing and it was still rather high for this type of alloys. The coercivity decreased after the annealing in comparison with as-built state from 200 to 100 A/m that is rather high for soft magnetic alloys however it is lower than that one of magnetic alloys produced by additive manufacturing methods and published elsewhere. The relative maximum permeability in this case rised from 1000 to 5000. The obtained results for μmax and Hc were discussed in terms of microstructure features which might be some kind of restriction for SLM technology of soft magnetic alloys manufacture.
•The SLM process of Fe–50%Ni soft magnetic alloy powder was successfully applied.•Magnetic properties evolution in dependence on temperature and holding time of heat treatment were investigated.•The obtained results on magnetic properties were discussed in terms of microstructure features and internal stresses.
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.
The Mini-EUSO detector was delivered on board the International Space Station in 2019 as part of the UV Atmosphere space experiment. The device was designed and manufactured by the international ...JEM-EUSO collaboration and is a prototype of the K-EUSO fluorescent orbital ultra-high-energy cosmic ray detector. Twenty-six sessions of the experiment were conducted over 1 year of the equipment’s operation on board the ISS. Slow variations in UV fluorescence were recorded (cloud cover and anthropogenic sources) as well as lightning discharges, transient high-atmosphere phenomena of thunderstorm origin, and meteors. A number of unusual UV flashes with durations of around 150 μs were recorded, the nature of which remains unclear.
The authors describe a EUSO-SPB2 balloon experiment to study ultra-high energy and extreme energy cosmic rays along with high-energy astrophysical neutrinos. The main characteristics of the ...fluorescent and Cherenkov telescopes are given. A multi-channel photodetectoris calibrated as part of the pre-flight preparation.
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 TUS detector was a highly sensitive orbiting telescope. Due to the spacecraft’s polar orbit, the detector was able to observe the UV emission of the atmosphere above the polar auroral oval. ...Events with vintensity variations characteristic of pulsating auroras were detected along the equatorial boundary of the auroral oval. These variations occurred during prolonged geomagnetic disturbances. When compared to data from charged particle detectors, they revealed an increased flux of precipitating high-energy electrons with energies of more than 100 keV along with UV pulsations.
The main goal of the Vernov mission is the study of magnetospheric relativistic electron precipitation and its possible influence on the upper atmosphere as well as the observation of Transient ...Luminous Events (TLE) and Terrestrial Gamma Flashes (TGF) across a broad range of the electromagnetic spectrum.
The RELEC (Relativistic Electrons) instrument complex onboard the Vernov spacecraft includes two identical X- and gamma-ray detectors of high temporal resolution and sensitivity (DRGE-1 and DRGE-2), three axis position detectors for high-energy electrons and protons (DRGE-3), a UV TLE imager (MTEL), a UV detector (DUV), a low frequency analyser (LFA), a radio frequency analyser (RFA), and AN electronics module responsible for control and data collection (BE).
The RELEC mission conducts the following experiments:
–simultaneous observations of high-energy electron and proton fluxes (within the energy range of ∼0.1–10.0MeV) and low-frequency (∼0.1–10kHz) electromagnetic wave field intensity variations with high temporal resolution (∼1ms);–fine time structure (∼1μs) measurements of transient atmospheric events in UV, X- and gamma rays with an optical imaging capability with a resolution of ∼1km in wide field of view (FOV);–measurements of electron flux pitch-angle distributions in dynamical ranges from ∼0.1 up to 105 part/cm2/s;–monitoring of charged and neutral background particles in different areas of near-Earth space.
Observations of a faint pulsating UV emission from the atmosphere in the region of auroral oval were made by a highly sensitive satellite telescope TUS with a milliseconds temporal resolution.
The ...TUS detector was launched in April 2016 on board the Lomonosov spacecraft. TUS was designed to register the extensive air shower (EAS) fluorescent signal from ultra-high-energy cosmic rays in the wavelength range 300–400 nm. EAS fluorescence is a weak and rapidly moving signal in the detector's field of view (FOV). Therefore, the TUS detector was equipped with a 2 m2 mirror and high temporal resolution (0.8 μs) photo detector. The FOV of the device is 6400 km2, the angular resolution is 10 mrad, which corresponds to the 5×5 km square on the Earth surface. The Lomonosov satellite has a polar sun-synchronous orbit with an inclination of 97.3∘, which provides measurements up to the high latitudes on the night side of the orbit. The detector electronics implements several operating modes that differ in time resolution (from 0.8 μs to 6.6 ms) and measure optical phenomena of different time scales.
We analyze the near-UV glow in the northern polar region (50°–80° N), carried out in a mode with a temporal resolution of 6.6 ms and a waveform duration of 1.7 s. About 2500 observations were analyzed in a wide range of longitudes. A selection of events with the peculiar spatial-temporal dynamics of the signal was made. An analysis of the selected events structure and location relative to the auroral oval shows that fast pulsations are observed during disturbed geomagnetic conditions at the equatorial border of the auroral zone.
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•Detector TUS on board the satellite Lomonosov was measuring near-UV (NUV) radiation of the atmosphere observing in nadir.•Fast NUV pulsations were measured in the northern hemisphere in the range of latitudes from 52° N to 71° N.•The maximum portion of the pulsations is measured in the L-shells range from 4 to 6.•Number of measured events correlate with geomagnetic activity and most of them are measured with AE-index more than 200 nT.•Location of the events does not depend on geomagnetic activity level which istypical for the other auroral events.
EUSO-Balloon
is a pathfinder for
JEM-EUSO
, the mission concept of a spaceborne observatory which is designed to observe Ultra-High Energy Cosmic Ray (UHECR)-induced Extensive Air Showers (EAS) by ...detecting their UltraViolet (UV) light tracks “from above.” On August 25, 2014,
EUSO-Balloon
was launched from Timmins Stratospheric Balloon Base (Ontario, Canada) by the balloon division of the French Space Agency CNES. After reaching a floating altitude of 38 km,
EUSO-Balloon
imaged the UV light in the wavelength range ∼290–500 nm for more than 5 hours using the key technologies of
JEM-EUSO
. The flight allowed a good understanding of the performance of the detector to be developed, giving insights into possible improvements to be applied to future missions. A detailed measurement of the photoelectron counts in different atmospheric and ground conditions was achieved. By means of the simulation of the instrument response and by assuming atmospheric models, the absolute intensity of diffuse light was estimated. The instrument detected hundreds of laser tracks with similar characteristics to EASs shot by a helicopter flying underneath. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. The reconstruction of the direction of the laser tracks was performed. In this work, a review of the main results obtained by
EUSO-Balloon
is presented as well as implications for future space-based observations of UHECRs.
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