Hybrid Simulations for Pickup Ion Distributions at the Termination Shock

Kucharek, H.; Pogorelov, N.; Möbius, E.; Lee, M. A.

doi:10.1063/1.3529959

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effects of alpha particles on the magnetic profile of the shock were not considered. Kucharek et al [] have shown that superthermal pickup protons modify the shock profile when their density constitutes a large part, 30%, of the upstream plasma density. The shock transition width is substantially smaller than the upstream proton convective gyroradius, and the proton motion in the shock front is nonadiabatic.…”

Section: Introductionmentioning

confidence: 99%

Effect of alpha particles on the shock structure

Gedalin

2017

JGR Space Physics

View full text Add to dashboard Cite

The magnetic profile of a collisionless shock is shaped by ions. Dynamics of the ions is governed by the fields in the shock front. Species with different charge‐to‐mass ratio have different gyroradii; thus, their distributions upon crossing the shock became substantially different. Accordingly, the dependencies of the density and temperature on the coordinate along the shock normal should differ. In a stable one‐dimensional stationary shock the total pressure must remain constant throughout. Therefore, the magnetic pressure should anticorrelate with the particle pressure. Since the particle pressure is not uniform, downstream spatial magnetic oscillations should arise. Each of the species results in its own dependence of the pressure on the coordinate along the shock normal; therefore, the oscillations are not spatially periodic. The magnetic compression in the shocks with alpha particles is higher than the magnetic compression in purely proton shocks, while the amplitude of the downstream magnetic oscillations is lower.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of alpha particles on the shock structure

Gedalin

2017

JGR Space Physics

View full text Add to dashboard Cite

show abstract

“…Though nowadays it is expected that modern MHD shock simulations of the solar wind termination shock (see e.g. Li & Zank 2006;Kucharek et al 2006Kucharek et al , 2010Giacalone & Jokipii 2006) may suggest that ions under such conditions do not conserve their initial magnetic moment, many different conclusions opposite to that point have been achieved in earlier and alternative shock literature. If, for example, one studies the paper by Sarris & van Allen (1974), one finds that these authors successfully represent, by theoretical calculations, data on shock-processed ions near the Earth's bowshock observationally obtained by the satellites Explorer 33 and 35.…”

Section: Introductionmentioning

confidence: 83%

Revisiting the role of magnetic moments in heliospheric plasmas

Fahr

Siewert

2013

A&A

View full text Add to dashboard Cite

The magnetic moment is one of the most fundamental, nontrivial particle properties known in plasma physics. Also known as the first adiabatic invariant, it is conserved under a broad range of microphysical processes and plasma boundary conditions. However, especially in modern numerical simulations, the conservation of this property, which in principle may serve as a control parameter, is no longer used explicitly. In light of this fact, as well as in a recent series of studies of the solar wind termination shock and comparable systems, where this conservation was used as a key ingredient, we now revisit this old, but standing problem. Building on our earlier arguments on when the magnetic moment of individual particles is conserved, we now carefully expand this argument further, studying nontrivial systems, such as systems where individual ions are represented by a broad distribution function that is described with the help of a transport equation. We see that the magnetic moment is conserved under an even wider variety of situations than those studied in earlier publications. When studying systems of purely kinetic equations, the magnetic moment can be converted into an additional force term in the transport equation. We also study the physics that is taken into account in shock simulations and pinpoint weaknesses in the physics used by these modern codes.

show abstract