2.2.0 spase://SMWG/Instrument/Geotail/EPIC Geotail Energetic Particles and Ion Composition 2011-02-02T17:11:58Z The principal objective of the EPIC (Energetic Particles and Ion Composition) investigation is to explore the outer magnetosphere and the distant magnetotail region and obtain information on the origin, transport, storage, acceleration and dynamics of suprathermal and non-thermal particle populations. The instrument contains two main sensor heads. The STICS assembly (Supra-Thermal Ion Composition Spectrometer) uses a quadrispherical electrostatic analyzer followed by a foil/solid state detector time-of-flight (TOF) telescope to measure charge state, mass and energy of ions with energies of 10 - 230 keV/charge. The ICS assembly (Ion Composition Subsystem) measures the mass and energy of energetic ions with energies of less than 50 keV to 3 MeV. It uses a pair of collimators with sweeping magnets to reject electrons, followed by TOF and energy analysis. A thin foil/solid state detector electron telescope measures electrons higher than 30 keV. Directional measurements with a time resolution less than 3 s for all species are possible. A detailed instrument description, and a complete set of EPIC summary plots from launch to the present, plus on-line access to the digital data set, is available at the EPIC link below. spase://SMWG/Person/Anthony.T.Y.Lui PrincipalInvestigator spase://SMWG/Person/Donald.J.Williams FormerPI EPIC site at JHU_APL http://sd-www.jhuapl.edu/Geotail/ QuadrisphericalAnalyser Energetic Particles and Ion Composition spase://SMWG/Observatory/Geotail