In the dual-coolant lead lithium (DCLL) blanket, the key element is the flow channel insert (FCI) made of a silicon carbide composite (SiCf /SiC), which serves as electric and thermal insulator. The most important magnetohydrodynamic (MHD) and thermal issues of the FCI, associated with MHD flows and heat transfer in the poloidal channel of the blanket, were studied with numerical simulations us...

In Paper I (Fiege & Pudritz, 1999), we constructed models of filamentary molecular clouds that are truncated by a realistic external pressure and contain a rather general helical magnetic field. We address the stability of our models to gravitational fragmentation and axisymmetric MHD-driven instabilities. By calculating the dominant modes of axisymmetric instability, we determine the dominant ...

Cool weakly ionized gaseous rotating disk, are considered by many models as the origin of the evolution of protoplanetary clouds. Instabilities against perturbations in such disks play an important role in the theory of the formation of stars and planets. Thus, a hierarchy of successive fragmentations into smaller and smaller pieces as a part of the Kant-Laplace theory of formation of the plane...

New theory developments and experimental observations of two classes of energetic particle driven instabilities are reported. First is a new class of global MHD solutions resulting from coupling of the Alfvénic and acoustic fundamental MHD oscillations due to geodesic curvature. These modes, predicted theoretically and numerically and called Beta-induced Alfvén-Acoustic Eigenmodes (BAAEs), have...

Performing a stable, long duration simulation of driven MHD turbulence with a high thermal Mach number and a strong initial magnetic field is a challenge to high-order Godunov ideal MHD schemes because of the difficulty in guaranteeing positivity of the density and pressure. We have implemented a robust combination of reconstruction schemes, Riemann solvers, limiters, and Constrained Transport ...

The magnetohydrodynamic ~MHD! stability of negative central magnetic shear toroidal equilibria with q.2 everywhere and ebpol@1 is investigated. Here, q is the safety factor of the equilibrium magnetic field in a torus with inverse aspect ratio e , and bpol is the ratio of the plasma pressure to the pressure in the poloidal magnetic field. At small ebpol!1, the elimination of the q52 resonant su...

Recent advances in understanding of the basic properties of compressible Magnetohydrodynamic (MHD) turbulence call for revisions of some of the generally accepted concepts. First, MHD turbulence is not so messy as it is usually believed. In fact, the notion of strong non-linear coupling of compressible and incompressible motions is not tenable. Alfven, slow and fast modes of MHD turbulence foll...

Two-dimensional (2-D) homogeneous magnetohydrodynamic (MHD) turbulence has many of the same qualitative features as three-dimensional (3-D) homogeneous MHD turbulence. These features include several ideal invariants, along with the phenomenon of broken ergodicity. Broken ergodicity appears when certain modes act like random variables with mean values that are large compared to their standard de...

The study of incompressible magnetohydrodynamic (MHD) turbulence gives useful insights on many astrophysical problems. We describe a pseudo-spectral MHD code suitable for the study of incompressible turbulence. We review our recent works on direct three-dimensional numerical simulations for MHD turbulence in a periodic box. In those works, we use a pseudo-spectral code to solve the incompressib...

[1] We have recently extended the global magnetohydrodynamic (MHD) model BATS-R-US to account for pressure anisotropy. Since the inner magnetosphere dynamics cannot be fully described even by anisotropic MHD, we coupled our anisotropic MHD model with two inner magnetospheric models: the Rice Convection Model (RCM) and the Comprehensive Ring Current Model (CRCM). The coupled models provide bette...