Punctuated reversals of dipole magnetic field A long time-scale MHD simulation has first demonstrated the intermittent reversals of strong dipole magnetic field generated by the MHD dynamo process. Although generated magnetic energy transits between a high energy state and a low energy state several times, the reversal of magnetic field polarity occurs only in a high energy state (upper two panels). The radial component of the magnetic field on the outer spherical surface before, during, and after a dipole reversal is also shown in the lower panel.

Collisionless reconnection Three-dimensional particle simulation has revealed that two kinds of plasma instabilities grow in the collisionless current sheet, i.e., the lower hybrid drift instability (LHDI, left panel) and the drift kink instability (DKI, right panel). Collisionless reconnection is triggered by the DKI which becomes unstable as a result of the nonlinear deformation of current sheet by the LHDI.

Structure formation of a polymer chain in solution We carry out the molecular dynamics simulations of a polymer chain in solution in order to investigate the formation process of the orientationally ordered structure of a polymer chain. By quenching a randomly-oriented polymer chain in solution (left panel), a toroidal structure is formed first (middle panel), and then it changes into a folded orientationally-ordered structure (right panel).

Statistical theory of turbulence The nonlinear equation of turbulence is solved based on a theory called Lagrangian direct-interaction approximation. Small-scale statistics of turbulence of incompressible fluids have a universality irrespective of boundary conditions or the Reynolds number. The theoretical prediction (solid line) excellently expresses the universal function without any adjustable parameters.

Theory and Computer Simulation

Simulation Science

Virtual Reality

Fusion Plasmas

Physics of Self-Organization

Evolutional Principles of Self-Organization

NIFS	Theory and Computer Simulation Center