Sv. Chalov et Hj. Fahr, ENTROPY GENERATION AT THE MULTI-FLUID SOLAR-WIND TERMINATION SHOCK PRODUCING ANOMALOUS COSMIC-RAY PARTICLES, Planetary and space science, 43(8), 1995, pp. 1035-1043
Different from other work the solar wind termination shock is describe
d here as a multi-fluid phenomenon taking into account the wavefield-i
nduced, magnetohydrodynamic self-interaction of a multi-species plasma
, consisting of solar wind ions, pick-up ions and shock-generated anom
alous cosmic ray particles. Caused by the diffusive interaction of the
low- and high-energy plasmas, an extended transition structure of the
shock is formed consisting of a precursor region and a gas dynamic su
b-shock. The inner-heliospheric pick-up ions, when convected with the
solar wind plasma towards the sub-shock, will serve there as a local s
ource, and all over the precursor region as a continuous source, of hi
gh energy particles via first-order Fermi acceleration in the shock-in
duced wave turbulences, thereby being energized from keV up to MeV ene
rgies and thus will operate as an entropy generator. The spatial diffu
sion of these high energy particles relative to the resulting, pressur
e-modified solar wind flow structure is described by a coupled system
of differential equations describing mass-, momentum-, and energy-flow
continuities for all plasma components. The energy loss due to escape
of energetic particles (MeV) from the precursor into the inner helios
phere is taken into account. The hydrodynamic properties of the anomal
ous cosmic ray gas and the low-energy solar wind are determined in a c
onsistent manner both for solutions with existing sub-shocks and for s
hock-free solutions. Also the variation of the compression ratio withi
n the shock structure is quantitatively determined and is related to t
he pick-up ion energization efficiency and to the mean energy of the d
ownstream anomalous cosmic ray particles. The variation of the resulti
ng shock structure and of the extent of solar wind sheath plasma beyon
d the shock is discussed with respect to its consequences for the LISM
neutral gas filtration and to the three-dimensional shape of the heli
osphere.