| 1. |
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| 2. |
- Abdellaoui, G., et al.
(författare)
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Cosmic ray oriented performance studies for the JEM-EUSO first level trigger
- 2017
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; , s. 150-163
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Tidskriftsartikel (refereegranskat)abstract
- JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5.10(19) eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics.
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| 3. |
- Abdellaoui, G., et al.
(författare)
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First observations of speed of light tracks by a fluorescence detector looking down on the atmosphere
- 2018
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Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221 .- 1748-0221. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- EUSO-Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25(th) of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector.
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| 4. |
- Abdellaoui, G., et al.
(författare)
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Meteor studies in the framework of the JEM-EUSO program
- 2017
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Ingår i: Planetary and Space Science. - : Elsevier. - 0032-0633 .- 1873-5088. ; 143, s. 245-255
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Tidskriftsartikel (refereegranskat)abstract
- We summarize the state of the art of a program of UV observations from space of meteor phenomena, a secondary objective of the JEM-EUSO international collaboration. Our preliminary analysis indicates that JEM-EUSO, taking advantage of its large FOV and good sensitivity, should be able to detect meteors down to absolute magnitude close to 7. This means that JEM-EUSO should be able to record a statistically significant flux of meteors, including both sporadic ones, and events produced by different meteor streams. Being unaffected by adverse weather conditions, JEM-EUSO can also be a very important facility for the detection of bright meteors and fireballs, as these events can be detected even in conditions of very high sky background. In the case of bright events, moreover, exhibiting some persistence of the meteor train, preliminary simulations show that it should be possible to exploit the motion of the ISS itself and derive at least a rough 3D reconstruction of the meteor trajectory. Moreover, the observing strategy developed to detect meteors may also be applied to the detection of nuclearites, exotic particles whose existence has been suggested by some theoretical investigations. Nuclearites are expected to move at higher velocities than meteoroids, and to exhibit a wider range of possible trajectories, including particles moving upward after crossing the Earth. Some pilot studies, including the approved Mini-EUSO mission, a precursor of JEM-EUSO, are currently operational or in preparation. We are doing simulations to assess the performance of Mini-EUSO for meteor studies, while a few meteor events have been already detected using the ground-based facility EUSO-TA.
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| 5. |
- Abdellaoui, G., et al.
(författare)
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Ultra-violet imaging of the night-time earth by EUSO-Balloon towards space-based ultra-high energy cosmic ray observations
- 2019
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Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 111, s. 54-71
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Tidskriftsartikel (refereegranskat)abstract
- The JEM-EUSO (Joint Experiment Missions for the Extreme Universe Space Observatory) program aims at developing Ultra-Violet (UV) fluorescence telescopes for efficient detections of Extensive Air Showers (EASs) induced by Ultra-High Energy Cosmic Rays (UHECRs) from satellite orbit. In order to demonstrate key technologies for JEM-EUSO, we constructed the EUSO-Balloon instrument that consists of a similar to 1 m(2) refractive telescope with two Fresnel lenses and an array of multi-anode photo-multiplier tubes at the focus. Distinguishing it from the former balloon-borne experiments, EUSO-Balloon has the capabilities of single photon counting with a gate time of 2.3 mu s and of imaging with a total of 2304 pixels. As a pathfinder mission, the instrument was launched for an 8 h stratospheric flight on a moonless night in August 2014 over Timmins, Canada. In this work, we analyze the count rates over similar to 2.5 h intervals. The measurements are of diffuse light, e.g. of airglow emission, back-scattered from the Earth's atmosphere as well as artificial light sources. Count rates from such diffuse light are a background for EAS detections in future missions and relevant factor for the analysis of EAS events. We also obtain the geographical distribution of the count rates over a similar to 780 km(2) area along the balloon trajectory. In developed areas, light sources such as the airport, mines, and factories are clearly identified. This demonstrates the correct location of signals that will be required for the EAS analysis in future missions. Although a precise determination of count rates is relevant for the existing instruments, the absolute intensity of diffuse light is deduced for the limited conditions by assuming spectra models and considering simulations of the instrument response. Based on the study of diffuse light by EUSO-Balloon, we also discuss the implications for coming pathfinders and future space-based UHECR observation missions.
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| 6. |
- Adams, J. H., Jr., et al.
(författare)
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A Review of the EUSO-Balloon Pathfinder for the JEM-EUSO Program
- 2022
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Ingår i: Space Science Reviews. - : Springer Nature. - 0038-6308 .- 1572-9672. ; 218:1
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Forskningsöversikt (refereegranskat)abstract
- 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 similar to 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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| 7. |
- Bacholle, S., et al.
(författare)
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Mini-EUSO Mission to Study Earth UV Emissions on board the ISS
- 2021
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Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 253:2
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Tidskriftsartikel (refereegranskat)abstract
- Mini-EUSO is a telescope observing the Earth in the ultraviolet band from the International Space Station. It is a part of the JEM-EUSO program, paving the way to future larger missions, such as K-EUSO and POEMMA, devoted primarily to the observation of ultrahigh-energy cosmic rays from space. Mini-EUSO is capable of observing extensive air showers generated by ultrahigh-energy cosmic rays with an energy above 10(21) eV and to detect artificial showers generated with lasers from the ground. Other main scientific objectives of the mission are the search for nuclearites and strange quark matter, the study of atmospheric phenomena such as transient luminous events, meteors, and meteoroids, the observation of sea bioluminescence and of artificial satellites and man-made space debris. Mini-EUSO will map the nighttime Earth in the UV range (290-430 nm), with a spatial resolution of about 6.3 km and a temporal resolution of 2.5 mu s, through a nadir-facing UV-transparent window in the Russian Zvezda module. The instrument, launched on 2019 August 22, from the Baikonur Cosmodrome, is based on an optical system employing two Fresnel lenses and a focal surface composed of 36 multianode photomultiplier tubes, 64 channels each, for a total of 2304 channels with single-photon counting sensitivity and an overall field of view of 44 degrees. Mini-EUSO also contains two ancillary cameras to complement measurements in the near-infrared and visible ranges. In this paper, we describe the detector and present the various phenomena observed in the first months of operations.
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| 8. |
- Bagheri, Mahdi, et al.
(författare)
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Overview of Cherenkov Telescope on-board EUSO-SPB2 for the Detection of Very-High-Energy Neutrinos
- 2022
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Ingår i: Proceedings of Science. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- We present the status of the development of a Cherenkov telescope to be flown on a long-duration balloon flight, the Extreme Universe Space Observatory Super Pressure Balloon 2 (EUSO-SPB2). EUSO-SPB2 is an approved NASA balloon mission that is planned to fly in 2023 and is a precursor of the Probe of Extreme Multi-Messenger Astrophysics (POEMMA), a candidate for an Astrophysics probe-class mission. The purpose of the Cherenkov telescope on-board EUSOSPB2 is to classify known and unknown sources of backgrounds for future space-based neutrino detectors. Furthermore, we will use the Earth-skimming technique to search for Very-High-Energy (VHE) tau neutrinos below the limb (E > 10 PeV) and observe air showers from cosmic rays above the limb. The 0.785 m2 Cherenkov telescope is equipped with a 512-pixel SiPM camera covering a 12.8° x 6.4° (Horizontal × Vertical) field of view. The camera signals are digitized with a 100 MS/s readout system. In this paper, we discuss the status of the telescope development, the camera integration, and simulation studies of the camera response.
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| 9. |
- Barrillon, P., et al.
(författare)
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The EUSO@TurLab project in the framework of the JEM-EUSO program
- 2023
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Ingår i: Experimental astronomy. - : Springer Nature. - 0922-6435 .- 1572-9508. ; 55:2, s. 569-602
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Tidskriftsartikel (refereegranskat)abstract
- The EUSO@TurLab project aims at performing experiments to reproduce Earth UV emissions as seen from a low Earth orbit by the planned missions of the JEM-EUSO program. It makes use of the TurLab facility, which is a laboratory, equipped with a 5 m diameter and 1 m depth rotating tank, located at the Physics Department of the University of Turin. All the experiments are designed and performed based on simulations of the expected response of the detectors to be flown in space. In April 2016 the TUS detector and more recently in October 2019 the Mini-EUSO experiment, both part of the JEM-EUSO program, have been placed in orbit to map the UV Earth emissions. It is, therefore, now possible to compare the replicas performed at TurLab with the actual images detected in space to understand the level of fidelity in terms of reproduction of the expected signals. We show that the laboratory tests reproduce at the order of magnitude level the measurements from space in terms of spatial extension and time duration of the emitted UV light, as well as the intensity in terms of expected counts per pixel per unit time when atmospheric transient events, diffuse nightlow background light, and artificial light sources are considered. Therefore, TurLab is found to be a very useful facility for testing the acquisition logic of the detectors of the present and future missions of the JEM-EUSO program and beyond in order to reproduce atmospheric signals in the laboratory.
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| 10. |
- Battisti, M., et al.
(författare)
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Overview of the Mini-EUSO μs trigger logic performance
- 2022
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Ingår i: 37th International Cosmic Ray Conference, ICRC 2021. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- Mini-EUSO is the first detector of the JEM-EUSO program deployed on the ISS. It is a wide field of view telescope currently operating from a nadir-facing UV-transparent window on the ISS. It is based on an array of MAPMTs working in photon counting mode with a 2.5 μs time resolution. Among the different scientific objectives it searches for light signals with time duration compatible to those expected from Extensive Air Showers (EAS) generated by EECRs interacting in the atmosphere. Although the energy threshold for cosmic ray showers is above E > 1021eV, due the constraints given by the size of the UV-transparent window, the dedicated trigger logic has been capable of the detection of other interesting classes of events, like elves and ground flashers. An overview of the general performance of the trigger system is provided, with a particular focus on the identification of classes of events responsible for the triggers.
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