New Topics
Published Paper (page 2)
"Development of MultiHierarchy Simulation Model with NonUniform
Space Grids for Collisionless Driven Reconnection"
S. Usami, R. Horiuchi, H. Ohtani, and M. Den,
Physics of Plasmas Vol.20, 061208 (2013)
Multihierarchy simulation result of magnetic reconnection. The left and
right panels display magnetic field lines and fluid velocity vectors. The
multihierarchy model is progressed from the previous model as follows.
First, the boundary condition in the downstream is improved from periodic
to open, thus outflow can go out across the downstream boundary. Furthermore,
nonuniform space grids are adopted in the macro hierarchy so as to calculate
larger region. 
"Analytic Equilibria of HighBeta Tokamaks with Toroidal and Poloidal
Flows and Pressure Anisotropy Associated with Parallel Heat Flux"
A. Ito and N. Nakajima,
Journal of the Physical Society of Japan Vol.82, 064502 (2013)
Profiles of pressures and the magnetic flux in the midplane (left) and
the radial component of the diamagnetic current in a poloidal cross section
(right) obtained from the analytic solution for tokamak equilibria with
flow and pressure anisotropy. 
"Formation and Classification of Amorphous Carbon by Molecular Dynamics
Simulation"
A. M. Ito, A. Takayama, S. Saito, and H. Nakamura,
Japanese Journal of Applied Physics Vol.52, 01AL04 (2013)
(Color online) Animation snapshots in the MD simulation for transition
from graphite to diamond at a pressure of 15 GPa. The green and red spheres
indicate sp^{2} and sp^{3} carbon atoms, respectively. The white lines show the side of the simulation
box under the periodic boundary condition. 
"Kinetic effects on robustness of electron magnetohydrodynamic structures"
M. Hata, H. Sakagami, and A. Das,
Physics of Plasmas Vol.20, 042303 (2013)
(a) Electron orbit in the case of R=8 at the temperature of 4 keV, where
black, blue, and pink lines indicate orbits and color contour represents
magnetic field in the z direction.
(b) Schematic for sustained mechanism of electron's orbit, where red shading
and yellow arrows express magnetic field in the z direction and radial
electric field, and purple and white circles and bluedriftedcircle represent
Larmor motion, circular motion via ExB drift, and electron orbit that results
from Larmor motion and ExB drift, respectively. 
"Macro and microphysics of magnetic reconnection in a multihierarchy
open system"
R. Horiuchi, M. Den, T. Tanaka, H. Ohtani, and S. Usami,
Plasma Physics and Controlled Fusion Vol.55, 014008 (2013)
Global MHD simulation of geomagnetosphere reconnection with kinetic resistivity.
Spatial profiles of magnetic field lines and pressure are plotted when
reconnection sets in (top panels) and when flux rope is formed (bottom
panels). The left and right panels stand for the results for an effective
resistivity model based on steady collisionless driven reconnection, and
those for a constant resistivity model. Color on the lines presents the
Bz intensity. 
"Visualization of Particle Trajectories in TimeVarying Electromagnetic
Fields by CAVEType Virtual Reality System"
N. Ohno, H. Ohtani, D. Matsuoka, R. Horiuchi,
Plasma and Fusion Research Vol.7, 1401001 (2012)
CAVE visualization of the timevarying data at (1) T=0, (2) 25 T, and (3)
50ΔT, where ΔT is time interval of storing the simulation data. The color
contours on xy and yz planes are ion temperature and a reconnection component
of magnetic field, respectively. The blue and white lines are magnetic
field and ion trajectories, respectively. The magnetic field lines are
drawn by the data at the each time, while the ion trajectories are shown
as timetracing lines from T=0. 
"Effects of long rarefied plasma on fast electron generation for FIREXI targets"
H. Sakagami, A. Sunahara, T. Johzaki, and H. Nagatomo,
Laser and Particle Beams Vol.30, 103109 (2012)
These figures show time evolutions of averaged core electron temperature
over the dense region (ρ>10 g/cm^{3}) without rarefied plasmas(purple)
and with rarefied plasmas of different densities, 0.01(green), 0.05(red),
0.1(blue), 0.5(yellow) and 1(gray) critical density for (a) Lrare=150 and
(b) 300 μm. 
"Simulation of Plasma Flow Injection with MultiHierarchy Model Aiming Magnetic Reconnection Studies"
S. Usami, H. Ohtani, R. Horiuchi, and M. Den,
Communications in Computational Physics Vol.11, 10061021 (2012)
Bird's eye view of the mass density in the multihierarhcy simulation. At the initial state, mass density is uniform. Plasmas smoothly and continuously flow from the MHD to PIC domains through the interface domain. 
"Visualization of ThreeDimensional MHD Simulation Data to Study Fine
Unstable Motions in a Helical Torus Device"
H. Miura,
IEEE TRANSACTIONS ON PLASMA SCIENCE, Vol.39, 2011
Isosurfaces of the pressure in a 3D MHD simulation of a hot magnetized
plasma dominated by the ballooning instability are visualized. The flutelike
structures of the isosurfaces indicates growth of the ballooning mode.
The yellow circle indicates the tangential port of the LHD. 


