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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Modeling Neutron Emissions in High Energy Atmospheric Phenomena

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Autor(es):
Diniz, G. [1, 2, 3] ; Rutjes, C. [3] ; Ebert, U. [3, 4] ; Ferreira, I. S. [1] ; Sao Sabbas, E. F. M. T. [2]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Brasilia, Inst Fis, Brasilia, DF - Brazil
[2] Inst Nacl Pesquisas Espaciais, Sao Jose Dos Campos - Brazil
[3] CWI, Amsterdam - Netherlands
[4] Eindhoven Univ Technol, Dept Appl Phys, Eindhoven - Netherlands
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES; v. 123, n. 22, p. 12726-12737, DEC 13 2018.
Citações Web of Science: 0
Resumo

Neutron emissions with different durations have been observed during thunderstorms. These neutrons can be produced by microsecond to millisecond fast Terrestrial Gamma-ray Flashes correlated with lightning, or by Gamma-ray Glows lasting several seconds to minutes. In both cases, the neutrons are produced through a photonuclear reaction of gamma rays in the energy range of 10 to 30 MeV with nuclei of air molecules. Here we present simulations of gamma-ray beams propagating downward from different source altitudes. In our analysis the primary photons with energies between 10 and 30 MeV are separated into four energy intervals, each of 5 MeV width. From these data, arbitrary spectra of primary photons and of their products can be composed. Our results indicate that the neutrons are created essentially along the trajectory of the primary photons and that they reach ground within a transversal area of radius below 500 m. This lateral spreading is dominated by neutron diffusion due to collisions with air molecules. A secondary longer lasting photon pulse at sea level is predicted as well by our simulations. We have introduced this Terrestrial Gamma-ray Flash afterglow already in (Rutjes et al. 2017, https://doi.org/10.1002/2017GL075552). It is due to neutron capture by air molecules, and it has recently been observed by Bowers et al. (2017, https://doi.org/10.1002/2017GL075071) and Enoto et al. (2017, https://doi.org/10.1038/nature24630). (AU)

Processo FAPESP: 12/20366-7 - LEONA: rede colaborativa na América Latina para a investigação de eventos luminosos transientes e emissões de alta energia de tempestades
Beneficiário:Eliah Fernanda de Maria de São Sabbas Tavares
Linha de fomento: Auxílio à Pesquisa - Regular