B. Lembege et F. Simonet, Hybrid and particle simulations of an interface expansion and of collisionless shock: A comparative and quantitative study, PHYS PLASMA, 8(9), 2001, pp. 3967-3981
The release of a hot and dense drifted plasma into a background ambient mag
netoplasma is analyzed with the help of one-dimensional hybrid and full par
ticle electromagnetic simulations, in conditions approaching those commonly
met in laboratory experiments. The overall study is mainly focused on the
early times of the interaction between both plasmas and for a strictly perp
endicular expansion in the magnetic field. Two successive regimes are evide
nced: a "transitory" regime, where a characteristic interface builds up, fo
llowed by a second regime, where a shock forms. Our purpose in this study i
s to analyze in detail the differences inherent to each code, and to quanti
fy their impact on the corresponding simulation results. Several difficulti
es are identified throughout this comparison, since different assumptions a
re used within each code; a method based both on the best time/space scale
lengths fit and on a judicious choice of plasma and numerical parameters is
proposed in order to overcome these difficulties. The present results and
a similar comparative method may be easily extended when analyzing the dyna
mics of the interface expansion building up in laboratory plasmas (during e
xperiments of laser-target interactions), in space plasma (active experimen
ts), and when applied to open questions related to collisionless shocks. (C
) 2001 American Institute of Physics.