SPRG Seminars - Archive

October 18, 2005:

The MINIS Balloon Campaign to study Relativistic Electron Precipitation
John Sample, UCB/SSL

The MINIS balloon campaign was conducted during the magnetospheric disturbances of January 2005 to investigate the precipitation of relativistic (~1 MeV) electrons from the Earth's outer radiation belt. Four 40kg paylaods were launched in succession from the South African Antarctic Base SANAE IV and two from Churchill, Manitoba, Canada in order to make a multipoint measurement of electron loss by precipitation. Relativistic electron fluxes in the earth's radiation belt are highly variable and represent a poorly understood balance between acceleration and loss processes. Balloon-based experiments
directly measure precipitation and thus provide a method for quantifying these losses, while the nearly stationary platform allows for the separation of temporal and spatial variations. Each payload contained a 3" NaI scintillator for detection of bremsstrahlung X-rays produced as the electrons precipitate into the atmosphere. The Antarctic payloads also had DC and VLF E- and B- field instruments. A review of relativistic electrons in hte radiation belts, a history of previous balloon-borne studies, and results from the campaign will be presented.

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