S.E. Hawkins III, E.C. Roelof, R.E. Gold, D.K. Haggerty, G.C. Ho The Johns Hopkins University Applied Physics Laboratory Laurel, Maryland, 20723-6099 (firstname.lastname@example.org)
Observations of beam-like solar energetic electron events provide new insight into acceleration and transport of ~38-315 keV particles from the solar corona to 1 AU. The EPAM instrument on the ACE spacecraft provides a unique set of measurements with its magnetically deflected "pure" electron channels, enabling us to unambiguously discriminate ions from electrons. With this identification, we can then also utilize our higher sensitivity "foil" electron spectrometers (which could respond to ions if they are present). This combination of "pure" and "foil" electron measurements then uniquely allows us to construct pitch-angle distributions over nearly a full 180-degree range. The electron observations used in this study have time resolution ~1 minute. We report on a survey of energetic electron events with large anisotropies (max/min sector >5:1). Beam-like pitch-angle distributions imply nearly scatter-free propagation. Because these electrons are near-relativistic (beta ~0.4-0.7) knowledge of the path length back to the Sun should in principle permit one to compute the release time in the corona to within a few minutes [Roelof et al., this conference]. Although impulsive injection corresponds to the most obvious beam events, we often find periods lasting many hours with nearly constant intensity, implying constant outflow from the corona with no apparent correlation to the 1-8 angstrom x-ray emission.