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Observation And Study Of Giga Electron Volt Solar Energetic Particles Using The Milagrito Extensive Air Shower Detector, Abraham David Falcone

Doctoral Dissertations

Measurements of high energy emission from solar events can lead to an understanding of the solar energetic particle acceleration mechanism(s). Although the energy source of these mechanisms is known to reside in the solar magnetic field, the details of the acceleration process(es) have continued to elude researchers. By observing the particle emission at the upper limits of the spectrum, essential information about the location and the nature of the acceleration mechanism(s) can be obtained.

Milagrito was an extensive air shower observatory which operated as a prototype for the larger Milagro instrument. It operated from February 1997 to May 1998. Although …

Solar Flare Gamma-Ray Spectroscopy With Cgro-Comptel, Christopher Alex Young

Doctoral Dissertations

The X-ray and gamma-ray emission from solar flares provides important information about high-energy particles in solar flares. Energetic protons and ions interact with the solar atmosphere, giving rise to nuclear line emission at MeV energies and higher energy photons from the decay of neutral and charged pions. Electrons interact with the solar atmosphere producing a bremsstrahlung continuum. The solar flare spectrum is generally a superposition of these spectra with nuclear line emission dominating from ∼1--8 MeV and the bremsstrahlung at lower and higher energies. The main goal of this thesis has been to explain a small part of a gamma-ray …

Multipoint Measurements Of Field Aligned Current Density In The Auroral Zone, Yihua Zheng

Doctoral Dissertations

In this thesis we discuss the results of the Enstrophy sounding rocket, launched from Poker Flat Research Range on the evening of February 11, 1999. The rocket flew through a very dynamic auroral region with multiple bright arcs and into the polar cap. Four Free Flying Magnetometers employing autonomous, nano-spacecraft technology and designed by JPL were deployed from the main payload during the flight and multipoint magnetic field measurements were made.

Magnetic field data reduction was performed on data obtained from the FFMs. The data reduction procedure is very complicated in the sense that it requires transformation from a spinning …

Theoretical Mechanisms For Solar Eruptions, Jun Lin

Doctoral Dissertations

This thesis presents new theoretical models of solar eruptions which are derived from older models that involve a loss of equilibrium of the Sun's coronal magnetic field. These models consist of a magnetic flux rope nested within an arcade of magnetic loop. Prior to an eruption, the flux rope floats in the corona under a balance between magnetic compression and tension forces. When an eruption occurs, the magnetic compression exceeds the magnetic tension and causes the flux rope to be thrown outwards, away from the Sun. Three important factors which impact the occurrence and evolution of the eruptive processes are …

Non-Adiabatic Features In Magnetotail Fast Flows: Orbit Tracing And Data Comparisons, Bryan Michael Boll

Doctoral Dissertations

The purpose of this study is to investigate velocity space distribution functions in space plasmas. Orbit tracing methods are used to generate self-consistent models of several different magnetic and electric field configurations. Fast flows in the magnetotail are selected to be modeled using a relatively thin current sheet compared with quiet times. Four different electric fields are imposed, varying in characteristic thickness and magnitude. Using these four particle based models we were able to generate velocity distribution functions that show clear evidence of non-adiabatic features that depend on the electric field characteristic width. Several years of Geotail Comprehensive Plasma Instrumentation …