Occurrence of high-beta superthermal plasma events in the close environment of Jupiter's bow shock as observed by Ulysses

Journal Article · Tue Jan 04 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3544336· OSTI ID:21513137

Marhavilas, P K; Sarris, E T; Anagnostopoulos, G C ^[1]

---

1. Space Research Laboratory, Democritus University of Thrace, Vas. Sofias 12 St., 67100 Xanthi (Greece)

The ratio of the plasma pressure to the magnetic field pressure (or of their energy densities) which is known as the plasma parameter 'beta'({beta}) has important implications to the propagation of energetic particles and the interaction of the solar wind with planetary magnetospheres. Although in the scientific literature the contribution of the superthermal particles to the plasma pressure is generally assumed negligible, we deduced, by analyzing energetic particles and magnetic field measurements recorded by the Ulysses spacecraft, that in a series of events, the energy density contained in the superthermal tail of the particle distribution is comparable to or even higher than the energy density of the magnetic field, creating conditions of high-beta plasma. More explicitly, in this paper we analyze Ulysses/HI-SCALE measurements of the energy density ratio (parameter {beta}{sub ep}) of the energetic ions'(20 keV to {approx}5 MeV) to the magnetic field's in order to find occurrences of high-beta ({beta}{sub ep}>1) superthermal plasma conditions in the environment of the Jovian magnetosphere, which is an interesting plasma laboratory and an important source of emissions in our solar system. In particular, we examine high-beta ion events close to Jupiter's bow shock, which are produced by two processes: (a) bow shock ion acceleration and (b) ion leakage from the magnetosphere.

• OSTI ID: 21513137
• Journal Information: AIP Conference Proceedings, Vol. 1320, Issue 1; Conference: Festschrift on modern challenges in nonlinear plasma physics: Honoring the career of Dennis Papadopoulos, Halkidiki (Greece), 15-19 Jun 2010; Other Information: DOI: 10.1063/1.3544336; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
DISTRIBUTION
EMISSION
ENERGY DENSITY
HIGH-BETA PLASMA
INTERACTIONS
JUPITER PLANET
KEV RANGE
MAGNETIC FIELDS
MEV RANGE 01-10
PARTICLES
PLANETARY MAGNETOSPHERES
PLASMA DENSITY
PLASMA PRESSURE
SHOCK WAVES
SOLAR SYSTEM
SOLAR WIND
TAIL IONS
ATMOSPHERES
CHARGED PARTICLES
ENERGY RANGE
IONS
MEV RANGE
PLANETARY ATMOSPHERES
PLANETS
PLASMA
SOLAR ACTIVITY
STELLAR ACTIVITY
STELLAR WINDS