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In‐Flight Observation of Positron Annihilation by ILDAS
We report a 511‐keV photon flux enhancement that was observed inside a thundercloud and is a result of positron annihilation. The observation was made with the In‐flight Lightning Damage Assessment System (ILDAS) on board of an A340 test aircraft. The aircraft was intentionally flying through a thun...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473548/ https://www.ncbi.nlm.nih.gov/pubmed/31032163 http://dx.doi.org/10.1029/2018JD028337 |
Sumario: | We report a 511‐keV photon flux enhancement that was observed inside a thundercloud and is a result of positron annihilation. The observation was made with the In‐flight Lightning Damage Assessment System (ILDAS) on board of an A340 test aircraft. The aircraft was intentionally flying through a thunderstorm at 12‐km altitude over Northern Australia in January 2016. Two gamma ray detectors showed a significant count rate increase synchronously with fast electromagnetic field variations registered by an on‐board antenna. A sequence of 10 gamma ray enhancements was detected, each lasted for about 1 s. Their spectrum mainly consists of 511‐keV photons and their Compton component. The local electric activity during the emission was identified as a series of static discharges of the aircraft. A full‐scale Geant4 model of the aircraft was created to estimate the emission area. Monte Carlo simulation indicated that the positrons annihilated in direct vicinity or in the aircraft body. |
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