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Measurements of the spatial structure and directivity of 100 kev photon sources in solar flares using pvo and isee-3 spacecraft
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Anderson, Kinsey A. |
| Copyright Year | 1991 |
| Description | The objective of this grant was to measure the spatial structure and directivity of the hard X-ray and low energy gamma-ray (100 keV-2 MeV) continuum sources in solar flares using stereoscopic observations made with spectrometers aboard the Pioneer Venus Orbiter (PVO) and Third International Sun Earth Explorer (ISEE-3) spacecraft. Since the hard X-ray emission is produced by energetic electrons through the bremsstrahlung process, the observed directivity can be directly related to the 'beaming' of electrons accelerated during the flare as they propagate from the acceleration region in the corona to the chromosphere/transition region. Some models (e.g., the thick-target model) predict that most of the impulsive hard X-ray/low energy gamma-ray source is located in the chromosphere, the effective height of the X-ray source above the photosphere increasing with the decrease in the photon energy. This can be verified by determining the height-dependence of the photon source through stereoscopic observations of those flares which are partially occulted from the view of one of the two spacecraft. Thus predictions about beaming of electrons as well as their spatial distributions could be tested through the analysis proposed under this grant. |
| File Size | 133287 |
| Page Count | 3 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19940010019 |
| Archival Resource Key | ark:/13960/t7qp11r75 |
| Language | English |
| Publisher Date | 1991-02-20 |
| Access Restriction | Open |
| Subject Keyword | Solar Physics Solar Corona Gamma Ray Spectrometers Chromosphere Solar Flares Bremsstrahlung Spaceborne Astronomy Stereoscopy X Ray Spectroscopy X Ray Fluorescence Photons Energetic Particles Directivity Gamma Rays Spatial Distribution Solar X-rays Solar Electrons Pioneer Venus 1 Spacecraft Adiabatic Conditions International Sun Earth Explorer 3 Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
