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41.
Gamma Ray Showers Observed at Ground Level in Coincidence With Downward Lightning Leaders
J. P. Lundquist, R.U. Abbasi, 2018, izvirni znanstveni članek

Opis: Bursts of gamma ray showers have been observed in coincidence with downward propagating negative leaders in lightning flashes by the Telescope Array Surface Detector (TASD). The TASD is a 700‐km^2 cosmic ray observatory located in southwestern Utah, USA. In data collected between 2014 and 2016, correlated observations showing the structure and temporal development of three shower‐producing flashes were obtained with a 3‐D lightning mapping array, and electric field change measurements were obtained for an additional seven flashes, in both cases colocated with the TASD. National Lightning Detection Network information was also used throughout. The showers arrived in a sequence of 2–5 short‐duration (≤10 μs) bursts over time intervals of several hundred microseconds and originated at an altitude of ≃3–5 km above ground level during the first 1–2 ms of downward negative leader breakdown at the beginning of cloud‐to‐ground lightning flashes. The shower footprints, associated waveforms and the effect of atmospheric propagation indicate that the showers consist primarily of downward‐beamed gamma radiation. This has been supported by GEANT simulation studies, which indicate primary source fluxes of ≃10^12–10^14 photons for 16° half‐angle beams. We conclude that the showers are terrestrial gamma ray flashes, similar to those observed by satellites, but that the ground‐based observations are more representative of the temporal source activity and are also more sensitive than satellite observations, which detect only the most powerful terrestrial gamma ray flashes.
Najdeno v: ključnih besedah
Povzetek najdenega: ...in lightning flashes by the Telescope Array Surface Detector (TASD). The TASD is a 700‐km^2...
Ključne besede: gamma rays, lightning, gamma ray bursts, surface detector
Objavljeno: 30.04.2020; Ogledov: 558; Prenosov: 0
.pdf Polno besedilo (1,14 MB)

42.
Search for EeV protons of galactic origin
J. P. Lundquist, R.U. Abbasi, 2016, izvirni znanstveni članek

Opis: Cosmic rays in the energy range 10^18.0–10^18.5 eV are thought to have a light, probably protonic, composition. To study their origin one can search for anisotropy in their arrival directions. Extragalactic cosmic rays should be isotropic, but galactic cosmic rays of this type should be seen mostly along the galactic plane, and there should be a shortage of events coming from directions near the galactic anticenter. This is due to the fact that, under the influence of the galactic magnetic field, the transition from ballistic to diffusive behavior is well advanced, and this qualitative picture persists over the whole energy range. Guided by models of the galactic magnetic field that indicate that the enhancement along the galactic plane should have a standard deviation of about 20° in galactic latitude, and the deficit in the galactic anticenter direction should have a standard deviation of about 50° in galactic longitude, we use the data of the Telescope Array surface detector in 10^18.0 to 10^18.5 eV energy range to search for these effects. The data are isotropic. Neither an enhancement along the galactic plane nor a deficit in the galactic anticenter direction is found. Using these data we place an upper limit on the fraction of EeV cosmic rays of galactic origin at 1.3% at 95% confidence level.
Najdeno v: ključnih besedah
Povzetek najdenega: ...use the data of the Telescope Array surface detector in 10^18.0 to 10^18.5 eV energy...
Ključne besede: Cosmic ray, Galactic protons, Telescope array, Surface detector
Objavljeno: 30.04.2020; Ogledov: 450; Prenosov: 0
.pdf Polno besedilo (840,97 KB)

43.
CORSIKA Simulation of the Telescope Array Surface Detector
J. P. Lundquist, T. Abu-Zayyad, 2014, izvirni znanstveni članek

Opis: The Telescope Array is the largest experiment studying ultra-high energy cosmic rays in the northern hemisphere. The detection area of the experiment consists of an array of 507 surface detectors, and a fluorescence detector divided into three sites at the periphery. The viewing directions of the 38 fluorescence telescopes point over the air space above the surface array. In this paper, we describe a technique that we have developed for simulating the response of the array of surface detectors of the Telescope Array experiment. The two primary components of this method are (a) the generation of a detailed CORSIKA Monte Carlo simulation with all known characteristics of the data, and (b) the validation of the simulation by a direct comparison with the Telescope Array surface detector data. This technique allows us to make a very accurate calculation of the acceptance of the array. We also describe a study of systematic uncertainties in this acceptance calculation.
Najdeno v: ključnih besedah
Ključne besede: cosmic ray, extensive air shower, simulation, surface detector
Objavljeno: 19.05.2020; Ogledov: 344; Prenosov: 0
.pdf Polno besedilo (534,39 KB)

44.
Test benches for the upgrade of the Pierre AugerObservatory electronics
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Martina Boháčová, 2019, objavljeni znanstveni prispevek na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...Pierre Auger Observatory, surface detector station, electronics, test benches...
Ključne besede: Pierre Auger Observatory, surface detector station, electronics, test benches
Objavljeno: 16.06.2020; Ogledov: 322; Prenosov: 18
.pdf Polno besedilo (735,82 KB)

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Bounds on diffuse and point source fluxes of ultra-high energy neutrinos with the Pierre Auger Observatory
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Francisco Pedreira, 2019, objavljeni znanstveni prispevek na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...Pierre Auger Observatory, Auger Surface Detector, search for ultra-high energy (UHE) neutrinos,...
Ključne besede: Pierre Auger Observatory, Auger Surface Detector, search for ultra-high energy (UHE) neutrinos, upper limits on diffuse and point source UHE neutrino fluxes
Objavljeno: 21.12.2020; Ogledov: 57; Prenosov: 4
.pdf Polno besedilo (447,71 KB)

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