Thumbnail
Access Restriction
Open

Author Taut, Andreas ♦ Berger, Lars ♦ Drews, Christian ♦ Wimmer-Schweingruber, Robert F. ♦ Bochsler, Peter ♦ Klecker, Berndt
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ANISOTROPY ♦ APERTURES ♦ ASTROPHYSICS ♦ COMPARATIVE EVALUATIONS ♦ DISTRIBUTION FUNCTIONS ♦ HELIOSPHERE ♦ HELIUM IONS ♦ INTERPLANETARY MAGNETIC FIELDS ♦ MAGNETIC FIELD CONFIGURATIONS ♦ MAGNETOMETERS ♦ PARTICLE INTERACTIONS ♦ PLASMA ♦ SENSORS ♦ SOLAR WIND ♦ SPACE VEHICLES ♦ TIME-OF-FLIGHT METHOD ♦ VELOCITY
Abstract Interstellar PickUp Ions (PUIs) are created from neutrals coming from the interstellar medium that get ionized inside the heliosphere. Once ionized, the freshly created ions are injected into the magnetized solar wind plasma with a highly anisotropic torus-shaped Velocity Distribution Function (VDF). It has been commonly assumed that wave-particle interactions rapidly destroy this torus by isotropizing the distribution in one hemisphere of velocity space. However, recent observations of a He{sup +} torus distribution using PLASTIC on STEREO showed that the assumption of a rapid isotropization is oversimplified. The aim of this work is to complement these studies. Using He{sup +} data from the Charge Time-Of-Flight (CTOF) sensor of the Charge, ELement, and Isotope Analysis System (CELIAS) on-board the SOlar and Heliospheric Observatory (SOHO) and magnetic field data from the Magnetic Field Investigation (MFI) magnetometer of the WIND spacecraft, we derive the projected 1-D VDF of He{sup +} for different magnetic field configurations. Depending on the magnetic field direction, the initial torus VDF lies inside CTOF’s aperture or not. By comparing the VDFs derived under different magnetic field directions with each other we reveal an anisotropic signature of the He{sup +} VDF.
ISSN 0094243X
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-03-25
Publisher Place United States
Volume Number 1720
Issue Number 1


Open content in new tab

   Open content in new tab