CROSS-FIELD DIFFUSION OF ENERGETIC (100 keV to 2 MeV) PROTONS IN INTERPLANETARY SPACE

Autor(es)

da Costa, Jr., Edio ^[1] ; Tsurutani, Bruce T. ^[2] ; Alves, Maria Virginia ^[3] ; Echer, Ezequiel ^[3] ; Lakhina, Gurbax S. ^[4]

Afiliação do(s) autor(es)

^[1] IFMG, BR-35400000 Ouro Preto, MG - Brazil

^[2] CALTECH, Jet Prop Lab, Pasadena, CA 91109 - USA

^[3] INPE, BR-12227010 Sao Jose Dos Campos, SP - Brazil

^[4] Indian Inst Geomagnetism, Navi Mumbai 410218 - India

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 778, n. 2 DEC 1 2013.
• Citações Web of Science: 4

Resumo

Magnetic field magnitude decreases (MDs) are observed in several regions of the interplanetary medium. In this paper, we characterize MDs observed by the Ulysses spacecraft instrumentation over the solar south pole by using magnetic field data to obtain the empirical size, magnetic field MD, and frequency of occurrence distribution functions. The interaction of energetic (100 keV to 2 MeV) protons with these MDs is investigated. Charged particle and MD interactions can be described by a geometrical model allowing the calculation of the guiding center shift after each interaction. Using the distribution functions for the MD characteristics, Monte Carlo simulations are used to obtain the cross-field diffusion coefficients as a function of particle kinetic energy. It is found that the protons under consideration cross-field diffuse at a rate of up to approximate to 11% of the Bohm rate. The same method used in this paper can be applied to other space regions where MDs are observed, once their local features are well known. (AU)

• Processo FAPESP: 08/01288-0 - Simulações numéricas de emissões eletromagnéticas geradas por múltiplos feixes de elétrons associados a fenômenos solares potencialmente geoefetivos.
• Beneficiário: Fernando Jaques Ruiz Simões Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/05397-3 - Interação entre partículas energéticas e decréscimos magnéticos no meio interplanetário: difusão perpendicular ressonante e não ressonante
• Beneficiário: Ezequiel Echer
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional