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dc.contributor.author Najita, Kazutoshi en_US
dc.date.accessioned 2009-09-09T19:56:33Z en_US
dc.date.available 2009-09-09T19:56:33Z en_US
dc.date.issued 1969 en_US
dc.identifier.uri http://hdl.handle.net/10125/11814 en_US
dc.description Typescript. en_US
dc.description Bibliography: leaves [144]-149. en_US
dc.description xi, 149 l illus en_US
dc.description.abstract A white light flare is a rare impulsive event observed in the visible continuum radiating from localized regions during the early explosive stage of a few solar flares. A self-consistent model is developed which attempts to explain the white light flare in terms of an enhanced local black body radiation due to a temperature perturbation at about optical depth unity in the photosphere. Solar cosmic ray and radio observations indicate that energetic protons and electrons are generated during the early phase of a solar proton flare. The model assumes a blast of energetic electrons and protons in equal numbers in the 10 to 1000 MeV range, incident on the photosphere from above, releasing most of its energy to the ambient gas at about the depth one sees the normal photospheric continuum radiation. This is interpreted by the study in terms of a temperature perturbation of the layer and a reradiation of the energy from an optically thin medium with a radiative relaxation time of several seconds and a radiation temperature of several hundred degrees above the normal. For the purpose of analysis, an inverse power law energy distribution for the energetic particles is assumed, and the analysis is applied to the May 23, 1967 white light flare event. The number of energetic particles required to account for the enhanced continuum radiation by this mechanism is set between 10^31 and 10^32. No other process seems to account as efficiently for the observed emission except possibly the synchrotron process, but then only with the most favorable geometry. Since the Planck function at 6000 0 K predicts negligible radio and x-radiation, the model allows for the generation of these radiations by other mechanisms, for example, the synchrotron and bremsstrahlung mechanisms, respectively. Assuming that the bremsstrahlung mechanism is responsible for the hard x-radiation, the inverse power law distribution is truncated at the low energy end of the spectrum. The final result is a differential energy spectrum, dN/dE = 4 x 10^32 , 0.50 MeV < E < 1 MeV, = 4 X 10^32E^-(5/3), 1 MeV < E < 1 BeV, which would account for the radiations during the impulsive phase of the May 23, 1967 event. Although the predictions of the model agree well with the observations, new observations, particularly of white light polarization, are needed to test the model. en_US
dc.language.iso en-US en_US
dc.publisher [Honolulu] en_US
dc.relation Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Physics; no. 215 en_US
dc.rights All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. en_US
dc.subject Solar flares en_US
dc.subject Solar flares -- Mathematical models en_US
dc.title Enhanced black body radiation as a generating mechanism for white light solar flares en_US
dc.title White light solar flares en_US
dc.type Thesis en_US
dc.type.dcmi Text en_US

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