Speaker
Irina Lisina
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.3006.pdf
Essential changes of structural and dynamical properties in a Yukawa
system caused by amplitude instability
I. I. Lisina1, O. S. Vaulina1, 2, and E. A. Lisin1, 2
1
Joint Institute for High Temperatures RAS, Moscow, Russia
2
Moscow Institute of Physics and Technology, Dolgoprudny, Russia
The majority of theoretical studies on stability of a non-ideal media are based on the analysis
of linearized equations of motion and consideration of the dissipative or/and the dispersive
instabilities due to small deviations of particles from their equilibrium positions. However,
with the increase in particle kinetic temperature the amplitude instability can also develop.
Here we present the analysis of physical properties of a non-ideal particle system with a
temperature growth. We propose to investigate the amplitude stability, i.e. the stability to
any-size deviations (not just small ones) of particles from their equilibrium positions. The
presented approach to the amplitude instability prediction is based on the determination of an
inflection point for the potential energy of a system with an increase of its kinetic
temperature. We consider the process of formation of amplitude instability in a two-particle
Yukawa system for wide values range of screening parameter, friction coefficient, and
gradients of external electric field.
Numerical simulations have shown that an increase in grain temperature leads to essential
changes in the structural and dynamic properties of the system in the vicinity of the critical
magnitude of the coupling parameter. The special features observed close to the critical point
are caused by the formation of amplitude instability in the analyzed two-partical system (and
are similar to those that causes the melting for extended systems).
The new analytical approach proposed here can also be an effective tool for studying
amplitude instability in systems of interacting particles suspended in plasma with directed
ion flow which adds to the interaction forces a wake-mediated attractive force.
The work was partially supported by the Russian Foundation for Basic Research (Grant No.
16-08-00594), the Russian Ministry of Education and Science (Project No.
MK-2930.2017.8).
