scholarly journals Spectral Analysis of Individual Terrestrial Gamma-ray Flashes Detected by ASIM

2021 ◽  
Author(s):  
Anders Lindanger ◽  
Martino Marisaldi ◽  
David Sarria ◽  
Nikolai Østgaard ◽  
Nikolai Lehtinen ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Spectral Analysis ◽  
Energy Spectrum ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Gamma Ray ◽  
High Energy ◽  
Space Physics ◽  
Energy Calibration ◽  
Energy Detector

<p>Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond bursts of high-energy photons associated with lightning flashes in thunderstorms. The Atmosphere-Space Interactions Monitor (ASIM), launched in April 2018, is the first space mission specifically designed to detect TGFs. We will mainly focus on data from the High Energy Detector (HED) which is sensitive to photons with energies from 300 keV to > 30 MeV, and include data from the Low Energy Detector (LED) sensitive in 50 keV to 370 keV energy range. Both HED and LED are part of the Modular X- and Gamma-ray Sensor (MXGS) of ASIM.</p><p>The energy spectrum of TGFs, together with Monte Carlo simulations, can provide information on the production altitude and beaming geometry of TGFs. Constraints have already been set on the production altitude and beaming geometry using other spacecraft and radio measurements. Some of these studies are based on cumulative spectra of a large number of TGFs (e.g. [1]), which smooth out individual variability. The spectral analysis of individual TGFs has been carried out up to now for Fermi TGFs only, showing spectral diversity [2]. Crucial key factors for individual TGF spectral analysis are a large number of counts, an energy range extended to several tens of MeV, a good energy calibration as well as knowledge and control of any instrumental effects affecting the measurements.</p><p>Thanks to ASIM’s large effective area and low orbital altitude, single TGFs detected by ASIM have much more count statistics than observations from other spacecraft capable of detecting TGFs. By comparing Monte Carlo simulations to the energy spectrum from single ASIM TGFs we will aim to put stricter constraints on the production altitude and beaming geometry of TGFs. We will present the dataset, method, and some results of the spectral analysis of individual TGFs.</p><p>References:</p><p>1. Dwyer, J. R., and D. M. Smith (2005), A comparison between Monte Carlo simulations of runaway breakdown and terrestrial gamma-ray flash observations, Geophys. Res. Lett., 32, L22804, doi:10.1029/2005GL023848.</p><p>2. Mailyan et al. (2016), The spectroscopy of individual terrestrial gamma-ray flashes: Constraining the source properties, J. Geophys. Res. Space Physics, 121, 11,346–11,363, doi:10.1002/2016JA022702.</p>

Energy spectrum from single TGFs detected by ASIM

2020 ◽  
Author(s):  
Anders Lindanger ◽  
Martino Marisaldi ◽  
Nikolai Østgaard ◽  
Andrey Mezentsev ◽  
Torstein Neubert ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Spectral Analysis ◽  
Energy Spectrum ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Gamma Ray ◽  
High Energy ◽  
Energy Calibration ◽  
Energy Detector ◽  
Instrumental Effects

<p>Terrestrial Gamma-ray Flashes (TGFs) are sub milliseconds bursts of high energy photons associated with lightning flashes in thunderstorms. The Atmosphere-Space Interactions Monitor (ASIM), launched in April 2018, is the first space mission specifically designed to detect TGFs. We will mainly focus on data from the High Energy Detector (HED) which is sensitive to photons with energies from 300 keV to > 30 MeV, and include data from the Low Energy Detector (LED) sensitive in 50 keV to 370 keV energy range. Both HED and LED are part of the Modular X- and Gamma-ray Sensor (MXGS) of ASIM.<br><br>The energy spectrum of TGFs, together with Monte Carlo simulations, can provide information on the production altitude and beaming geometry of TGFs. Constraints have already been set on the production altitude and beaming geometry using other spacecraft and radio measurements. Some of these studies are based on cumulative spectra of a large number of TGFs (e.g. [1]), which smooth out individual variability. The spectral analysis of individual TGFs has been carried out up to now for Fermi TGFs only, showing spectral diversity [2]. Crucial key factors for individual TGF spectral analysis are a large number of counts, an energy range extended to several tens of MeV, a good energy calibration as well as knowledge and control of any instrumental effects affecting the measurements.</p><p>We strive to put stricter constraints on the production altitude and beaming geometry, by comparing Monte Carlo simulations to energy spectra from single ASIM TGFs. We will present the dataset and method, including the correction for instrumental effects, and preliminary results on individual TGFs.</p><p>Thanks to ASIM’s large effective area and low orbital altitude, single TGFs detected by ASIM have much more count statistics than observations from other spacecrafts capable of detecting TGFs. ASIM has detected over 550 TGFs up to date (January 2020), and ~115 have more than 100 counts. This allows for a large sample for individual spectral analysis.</p><p>References:</p><ol><li>Dwyer, J. R., and D. M. Smith (2005), A comparison between Monte Carlo simulations of runaway breakdown and terrestrial gamma-ray flash observations, Geophys. Res. Lett., 32, L22804, doi:10.1029/2005GL023848.</li> <li>Mailyan et al. (2016), The spectroscopy of individual terrestrial gamma-ray flashes: Constraining the source properties, J. Geophys. Res. Space Physics, 121, 11,346–11,363, doi:10.1002/2016JA022702.</li> </ol>

In-Situ Measurement of Artificial Nuclides in Seabed Sediments Based on Monte Carlo Simulations and an Underwater HPGe Detector

2019 ◽  
Vol 53 (3) ◽  
pp. 16-22
Author(s):  
Jinzhao Zhang ◽  
Hongzhi Li ◽  
Xianguo Tuo
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Energy Resolution ◽  
Hpge Detector ◽  
High Energy ◽  
In Situ Measurement ◽  
Energy Calibration ◽  
High Energy Resolution ◽  
Seabed Sediments

AbstractIn-situ measurement of marine sediment radioactivity does not destroy the stratification of radionuclides in the sediment. We develop a novel seabed sediment radioactive measurement technique using a High Purity Germanium (HPGe) detector. The overall measurement system is designed, and the detector energy calibration is performed. The efficiency is calculated based on Monte Carlo simulations using the MCNP5 code. We compared the efficiency and energy resolution with the NaI(Tl) detection through experiments. NaI(Tl) detection is incapable of identifying the 137Cs artificial nuclides in seabed sediments due to the energy resolution limit. Hence, underwater HPGe detection is utilized due to its high energy resolution, which enables the detection of artificial nuclides 137Cs. The proposed method is of great significance in evaluating marine radioactive pollution.

scholarly journals TARANIS XGRE and IDEE Detection Capability of Terrestrial Gamma-Ray Flashes and Associated Electron Beams

2017 ◽  
Author(s):  
David Sarria ◽  
Francois Lebrun ◽  
Pierre-Louis Blelly ◽  
Remi Chipaux ◽  
Philippe Laurent ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Electron Beams ◽  
Effective Area ◽  
Detection Rates ◽  
Transient Phenomena ◽  
Preliminary Model

Abstract. With a launch expected in 2018, the TARANIS micro-satellite is dedicated to the study of transient phenomena observed in association with thunderstorms. On-board the spacecraft, XGRE and IDEE are two instruments dedicated to study Terrestrial Gamma-ray Flashes (TGFs) and associated electron beams (TEBs). XGRE can detect electrons (energy range: 1 MeV to 10 MeV) and X/gamma-rays (energy range: 20 keV to 10 MeV), with a very high counting capability (about 10 million counts per second), and the ability to discriminate one type of particle from the other. The IDEE instrument is focused on electrons in the 80 keV to 4 MeV energy range, with the ability to estimate their pitch angles. Monte-Carlo simulations of the TARANIS instruments, using a preliminary model of the spacecraft, allow sensitive area estimates for both instruments. It leads to an averaged effective area of 425 cm2 for XGRE to detect X/gamma rays from TGFs, and the combination of XGRE and IDEE gives an average effective area of 255 cm2 to detect electrons/positrons from TEBs. We then compare these performances to RHESSI, AGILE, and Fermi GBM, using performances extracted from literature for the TGF case, and with the help of Monte-Carlo simulations of their mass models for the TEB case. Combining these data with with the help of the MC-PEPTITA Monte-Carlo simulations of TGF propagation in the atmosphere, we build a self-consistent model of the TGF and TEB detection rates of RHESSI, AGILE, and Fermi. It can then be used to estimate that TARANIS should detect about 225 TGFs/year and 25 TEBs/year.

scholarly journals TARANIS XGRE and IDEE detection capability of terrestrial gamma-ray flashes and associated electron beams

2017 ◽  
Vol 6 (2) ◽  
pp. 239-256 ◽  
Author(s):  
David Sarria ◽  
Francois Lebrun ◽  
Pierre-Louis Blelly ◽  
Remi Chipaux ◽  
Philippe Laurent ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Electron Beams ◽  
Effective Area ◽  
Detection Rates ◽  
Transient Phenomena ◽  
Using Data

Abstract. With a launch expected in 2018, the TARANIS microsatellite is dedicated to the study of transient phenomena observed in association with thunderstorms. On board the spacecraft, XGRE and IDEE are two instruments dedicated to studying terrestrial gamma-ray flashes (TGFs) and associated terrestrial electron beams (TEBs). XGRE can detect electrons (energy range: 1 to 10 MeV) and X- and gamma-rays (energy range: 20 keV to 10 MeV) with a very high counting capability (about 10 million counts per second) and the ability to discriminate one type of particle from another. The IDEE instrument is focused on electrons in the 80 keV to 4 MeV energy range, with the ability to estimate their pitch angles. Monte Carlo simulations of the TARANIS instruments, using a preliminary model of the spacecraft, allow sensitive area estimates for both instruments. This leads to an averaged effective area of 425 cm2 for XGRE, used to detect X- and gamma-rays from TGFs, and the combination of XGRE and IDEE gives an average effective area of 255 cm2 which can be used to detect electrons/positrons from TEBs. We then compare these performances to RHESSI, AGILE and Fermi GBM, using data extracted from literature for the TGF case and with the help of Monte Carlo simulations of their mass models for the TEB case. Combining this data with the help of the MC-PEPTITA Monte Carlo simulations of TGF propagation in the atmosphere, we build a self-consistent model of the TGF and TEB detection rates of RHESSI, AGILE and Fermi. It can then be used to estimate that TARANIS should detect about 200 TGFs yr−1 and 25 TEBs yr−1.

Observation of a Terrestrial Electron Beam during the tropical cyclone Joaninha in March 2019

2020 ◽  
Author(s):  
David Sarria ◽  
Pavlo Kochkin ◽  
Nikolai Østgaard ◽  
Andrew Mezentsev ◽  
Nikolai G. Lehtinen ◽  
...  
Keyword(s):  
Electron Beam ◽  
Tropical Cyclone ◽  
Gamma Ray ◽  
High Energy ◽  
Space Physics ◽  
Low Energy ◽  
Energy Detector ◽  
Relativistic Electrons ◽  
Geophysical Research ◽  
Detection Frequency

<p>Terrestrial Gamma-ray Flashes (TGFs) are short (~20 us to ~2 ms) flashes of high energy (< 40 MeV) photons, produced by thunderstorms When interacting with the atmosphere, the TGF’s photons produce relativistic electrons and positrons at higher altitudes, and a fraction is able to escape the atmosphere [1,2,3]. The electrons/positrons are then bounded to Earth's magnetic field lines and can travel large distances inside the ionosphere and the magnetosphere. This phenomenon is called a Terrestrial Electron Beam (TEB).</p><p>The Atmosphere-Space Interactions Monitor (ASIM), dedicated to the study of TGF and associated events, started to operate in June 2018. ASIM contains an optical instrument (MMIA) made of micro-cameras and photometers, as well the Modular X and Gamma-ray Sensor (MXGS) for high energy radiation. MXGS is composed of the low energy detector (LED, 50 keV to 400 keV) and the High Energy detector (HED, 300 keV to 40 MeV). </p><p>This presentation is focused on a new event which was detected on March 24, 2019. The TEB originated from rainbands produced by the tropical cyclone Joaninha, in the Indian Ocean, close to Madagascar. This observation shows, for the first time to our knowledge: (1) the low energy part (>50 keV) of the TEB spectrum, using the LED, (2) an estimate of the incoming direction (to ISS) of the electron Beam from recorded data.</p><p>References:</p><p>[1] J. R., Dwyer, B. W., Grefenstette and D. M. Smith. High-energy electron beams launched into space by thunderstorms. DOI: 10.1029/2007GL032430. Geophysical Research Letters, 2008.</p><p>[2] B. E. Carlson T. Gjesteland N. Østgaard. Terrestrial gamma-ray flash electron beam geometry, fluence, and detection frequency. DOI: 10.1029/2011JA016812. Journal of Geophysical Research (Space Physics), 2011.</p><p>[3] D. Sarria, P. Kochkin, N. Østgaard et al. The First Terrestrial Electron Beam Observed by the Atmosphere-Space Interactions Monitor. DOI: 10.1029/2019JA027071. Journal of Geophysical Research (Space Physics), 2019.</p>

scholarly journals Gamma-ray counterparts of 2WHSP high-synchrotron-peaked BL Lac objects as possible signatures of ultra-high-energy cosmic ray emission

2020 ◽  
Vol 497 (2) ◽  
pp. 2455-2468
Author(s):  
Michael W Toomey ◽  
Foteini Oikonomou ◽  
Kohta Murase
Keyword(s):  
Energy Range ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Potential Candidate ◽  
Ultra High Energy ◽  
Bl Lac Objects ◽  
Cherenkov Telescopes ◽  
Bl Lac ◽  
Γ Ray

ABSTRACT We present a search for high-energy γ-ray emission from 566 Active Galactic Nuclei at redshift z > 0.2, from the 2WHSP catalogue of high-synchrotron peaked BL Lac objects with 8 yr of Fermi-LAT data. We focus on a redshift range where electromagnetic cascade emission induced by ultra-high-energy cosmic rays can be distinguished from leptonic emission based on the spectral properties of the sources. Our analysis leads to the detection of 160 sources above ≈5σ (TS ≥25) in the 1–300 GeV energy range. By discriminating significant sources based on their γ-ray fluxes, variability properties, and photon index in the Fermi-LAT energy range, and modelling the expected hadronic signal in the TeV regime, we select a list of promising sources as potential candidate ultra-high-energy cosmic ray emitters for follow-up observations by Imaging Atmospheric Cherenkov Telescopes.

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