OBSERVATION BY ULYSSES OF HOT (SIMILAR-TO-270 KEV) CORONAL PARTICLES AT 32-DEGREES SOUTH HELIOLATITUDE AND 4.6 AU

An unusual event of streaming 60 keV-2 MeV ions (with energy spectrum peaked approximately 270 keV) and of 42-315 keV electrons occurred dur ing the passage of a coronal mass ejection (CME) over the Ulysses spac ecraft June 9-13, 1993, located at helioradius 4.6 AU and heliolatitud e 32-degrees south. The topology of the interplanetary magnetic field (IMF) within the CME has been identified as a helical magnetic flux ro pe by Gosling et al. [1994]. The ion and electron pitch angle distribu tions (PADs) had a bidirectional component in the outer (large-pitch) regions of the flux rope, while there were strongly unidirectional (an tisunward) beams in the inner (small-pitch) core of the structure, whe re the electron PADs also displayed a distinctive depletion of electro ns moving inward (sunward). Because the core ion beam was narrow, we c an associate the observed energy spectrum in the peak direction of the beam (characterized by a Maxwellian with kT = 270 keV) directly with the spectrum injected in the inner heliosphere. The well-defined spati al structure of the event and the absence of any clear signatures of l ocal interplanetary shock acceleration during the period June 9-17 imp lies that the injection source could have been a long-lived hot corona l ion population. The ''weak scattering'' electron PAD implies that th e other (antisunward) end of the core of the flux rope was magneticall y connected, not back to the sun, but rather to the outer heliosphere.