Interstellar Helium Pickup Ion Flux Variations Observed By SOHO CELIAS

Interstellar pickup ions are formed when neutral atoms freely enter our heliosphere and are subsequently ionized. Once these particles are charged they become a component of the interplanetary plasma and are transported outward with the solar wind (SW). Measurements of these particles give information about the local interstellar gas in which our sun resides. However, fluxes of pickup ions in the solar wind are observed to vary substantially in both magnitude and energy spectrum. These variations are something of a mystery, however in this thesis the variations are shown to be related to solar wind properties and structures.