Suprathermal electron loss cone distributions in the solar wind: Ulysses observations

Conference · Fri Sep 01 04:00:00 EDT 1995

OSTI ID:105101

Phillips, J L; Feldman, W C; Gosling, J T ^[1]; Hammond, C M ^[2]; Forsyth, R J ^[3]

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1. Los Alamos National Lab., NM (United States)
2. SRI International, Menlo Park, CA (United States)
3. Imperial Coll. of Science and Technology, London (United Kingdom)

We present observations by the Ulysses solar wind plasma experiment of a new class of suprathermal electron signatures. At low solar latitudes and heliocentric distances beyond 3.37 AU Ulysses encountered seven intervals, ranging in duration from 1 hour to 22 hours, in which the suprathermal distributions included an antisunward field-aligned beam and a return population with a flux dropout typically spanning {plus_minus}60 ft from the sunward field-aligned direction. All events occurred between the forward and reverse shocks or waves bounding corotating interaction regions (CIRs). The observations support a scenario in which the sunward-moving electrons result from reflection of the prevailing antisunward field-aligned beam at magnetic field compressions downstream from the spacecraft, with wide loss cones caused by the relatively weak mirror ratio. This hypothesis requires that the field magnitude within the CIRs actually increased locally with increasing field-aligned distance from the Sun.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 105101
• Report Number(s): LA-UR--95-2664; CONF-9506256--1; ON: DE95016967
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DISTRIBUTION FUNCTIONS
LOSS CONE
PLASMA
RADIATION PRESSURE
SOLAR WIND
TAIL ELECTRONS