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@PhDThesis{Trevisan:1991:EsMuEx,
               author = "Trevisan, Rute Helena",
                title = "Estudos multiespectrais das explos{\~o}es solares associadas com 
                         a fase impulsiva do flare",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "1991",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "1991-03-26",
             keywords = "explos{\~o}es solares, ondas de r{\'a}dio, estudos 
                         multiespectrais, solar explosions, radio waves, multispectral 
                         studies.",
             abstract = "Existem poucos estudos de observa{\c{c}}{\~o}es multiespectrais 
                         com alta sensibilidade e resolu{\c{c}}{\~a}o em 
                         tempo/frequ{\^e}ncia/energia. A import{\^a}ncia de tais 
                         investiga{\c{c}}{\~o}es e que estes estudos nos permitem 
                         observar o desenvolvimento do fen{\^o}meno associado 
                         simultaneamente em varias alturas na atmosfera solar, e do qual 
                         podemos obter informa{\c{c}}{\~o}es sobre a regi{\~a}o de 
                         acelera{\c{c}}{\~a}o, propaga{\c{c}}{\~a}o de 
                         part{\'{\i}}culas aceleradas na dire{\c{c}}{\~a}o da 
                         fotosfera, e coroa e emiss{\~a}o causada por essas 
                         part{\'{\i}}culas. Essas informa{\c{c}}{\~o}es podem nos 
                         explicar melhor os processos de libera{\c{c}}{\~a}o de energia 
                         no flare solar. Nos investigamos aqui, explos{\~o}es solares em 
                         H- , raios-X, microondas, ondas decim{\'e}tricas e m{\'e}tricas, 
                         na fase impulsiva do flare. Os estudos simult{\^a}neos das 
                         explos{\~o}es solares de ondas milim{\'e}tricas e m{\'e}tricas 
                         e suas estruturas-finas, tem sugerido que as part{\'{\i}}culas 
                         s{\~a}o aceleradas para energias de at{\'e} 200 KeV; 
                         estruturas-finas s{\~a}o geradas por part{\'{\i}}culas 
                         aceleradas em processos secund{\'a}rios. Al{\'e}m disso 
                         aquecimento e acelera{\c{c}}{\~a}o ocorrem simultaneamente no 
                         flare solar. As observa{\c{c}}{\~o}es foram realizadas com a 
                         antena de 13,7 m de di{\^a}metro de Atibaia, pela primeira vez 
                         operando na faixa de decim{\'e}tricas (1663 MHz) com alta 
                         sensibilidade e resolu{\c{c}}{\~a}o temporal. N{\'o}s 
                         observamos pela primeira vez: i) blips acima de 1000 MHz, ii) 
                         explos{\~o}es homologas-like em microondas e spikes de baixa 
                         intensidade de fluxo. As investiga{\c{c}}{\~o}es mostraram que 
                         blips s{\~a}o variantes das explos{\~o}es tipo III e s{\~a}o 
                         geradas pela intera{\c{c}}{\~a}o do feixe de el{\'e}tros com 
                         plasma, no segundo harm{\^o}nico. Spikes s{\~a}o gerados por 
                         ECM, e, assumindo-se a instabilidade MHD as dimens{\~o}es de 
                         fonte s{\~a}o estimadas em 50 Km. Os flares hom{\'o}logos-like 
                         de per{\'{\i}}odo longos de repeti{\c{c}}{\~a}o (~ 40 min), 
                         s{\~a}o explicados pela oscila{\c{c}}{\~a}o de 
                         proemin{\^e}ncia, como tamb{\'e}m os hom{\'o}logos de 
                         per{\'{\i}}odos curtos de repeti{\c{c}}{\~a}o (~ 10s). 
                         Investiga{\c{c}}{\~o}es mais detalhadas dessas explos{\~o}es 
                         apresentadas aqui, leva-nos finalmente a sugerir que a energia do 
                         flare solar e liberada em pequenos volumes e escalas de tempo 1.e. 
                         ocorre a fragmenta{\c{c}}{\~a}o de energia quando o fluxo 
                         emergente entra em contato com o campo magn{\'e}tico existente. 
                         ABSTRACTS: There are a few studies of multispectral observations 
                         with high sensitivity and time/frequency/energy resolution. 
                         Importance of such investigations is that these studies allow to 
                         see time development of the associated phenomenon simultaneously 
                         at various heights in the solar atmosphere, from which one can 
                         gather information about the region of acceleration, propagation 
                         of accelerated particles towards and away from the photosphere and 
                         emission caused by these particles, which can throw light on the 
                         processes of liberation of energy in solar fiares. Here,we have 
                         investigated solar bursts occurring in H-a, hard X-rays, 
                         microwave, decimeter and meter wave in impulsive phase of the 
                         solar flare. Simultaneous studies of millimeter-wave and 
                         meter-wave bursts and its fine structure have suggested that 
                         particles are accelerated up to energies ~200 keV , and 
                         \λ-meter-wave fine structure 1 generated by the particles 
                         accelerated in a secondary process. Moreover heating and 
                         acceleration occurs simultaneously in the solar flare. Using 13.7 
                         m Atibaia antena decimetric, 1663 MHz, observations have been 
                         carried out for the first time with high sensitivity and high time 
                         resolution. We observed for the first time low flux level blips 
                         above 1000 MHz , spikes and microwave homologous like bursts. 
                         Investigations showed that blips are variants of type III bursts 
                         and are generated by beam plasma interaction at second harmonic. 
                         Spikes are assumed to be generated by E.C.M. and, assuming M. H. 
                         D. instability, estimated dimensions of radio sources are of the 
                         order of 50 km. Oscillations of prominences offer better 
                         explanation for long period , 40 minute, homologous bursts and can 
                         explain small periodicities of the order of 10 seconds. More 
                         detailed investigations of the bursts presented here, finally lead 
                         us to suggest that the flare energy is liberated in a small volume 
                         over small time scales i.e. there is fragmentation of energy when 
                         emerging magnetic flux comes in contact with the existing magnetic 
                         field.",
            committee = "Kane, Rajaram Purushottam (presidente) and Sawant, Hanumant 
                         Shankar (orientador) and Landaberry, Sayd Jos{\'e} Codina and 
                         L{\'e}pine, Jacques Raymond Daniel and Gonzalez-Alarcon, Walter 
                         Dem{\'e}trio and Scalise J{\'u}nior, Eug{\^e}nio",
           copyholder = "SID/SCD",
         englishtitle = "Multiespectral studies of the solar bursts associated with 
                         impulsive phase.",
             language = "pt",
                pages = "204",
                  ibi = "6qtX3pFwXQZ3P8SECKy/DFbxQ",
                  url = "http://urlib.net/rep/6qtX3pFwXQZ3P8SECKy/DFbxQ",
           targetfile = "Rute Helena Trevisan 06_02_19.pdf",
        urlaccessdate = "2020, Aug. 15"
}


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