Theoretical and numerical research of wire array Z-pinch and dynamic hohlraum at IAPCM

Abstract

Dense Z-pinch plasmas are powerful and energy-efficient laboratory sources of x rays, and show the possibility to drive inertial confinement fusion (ICF). Recent advances in wire-array Z-pinch and Z-pinch dynamic hohlraum (ZPDH) researches at the Institute of Applied Physics and Computational Mathematics are presented in this paper. Models are setup to study different physical processes. A full circuit model (FCM) was used to study the coupling between Z-pinch implosion and generator discharge. A mass injection model with azimuthal modulation was setup to simulate the wire-array plasma initiation, and the two-dimensional MHD code MARED was developed to investigate the Z-pinch implosion, MRT instability, stagnation and radiation. Implosions of nested and quasispherical wire array were also investigated theoretically and numerically. Key processes of ZPDH, such as the array-foam interaction, formation of the hohlraum radiation, as well as the following capsule ablation and implosion, were analyzed with different radiation magneto-hydrodynamics (RMHD) codes. An integrated 2D RMHD simulation of dynamic hohlraum driven capsule implosion provides us the physical insights of wire-array plasma acceleration, shock generation and propagation, hohlraum formation, radiation ablation, and fuel compression.

The positivity‐preserving finite volume scheme with fixed stencils for anisotropic diffusion problems on general polyhedral meshes

“…The anisotropic diffusion problems are widely used in many scientific fields, such as inertial confinement fusion (ICF), 1 reservoir simulations, astrophysics, hydrogeology, plasma physics, semiconductor modeling, Navier–Stokes equations, biology, and so on. In some problems, the diffusion tensor $$$ \Lambda $$$ may be strongly anisotropic, heterogeneous, or discontinuous, which brings a great challenge to construct discretized schemes.…”

A linearity-preserving vertex interpolation algorithm for cell-centered finite volume approximations of anisotropic diffusion problems

“…Anisotropic diffusion problem arises in a wide range of scientific fields such as oil reservoir simulations, plasma physics and semiconductor modelling and so on. Here we are concerned with the simulation of 2 D Z-pinch driven inertial confinement fusion (Ding et al, 2016) where a certain magnetic diffusion process is coupled with radiation hydrodynamics and the accurate evaluation of magnetic field at cell vertices are required. There has been extensive study on developing efficient discretization schemes for accurate simulation of diffusion processes in these applications, the issues about which range from the classical stability and accuracy to some other desirable numerical properties, including symmetry and positive definiteness of the resulting linear system, local stencil, local conservation, positivity preserving, simplicity, robustness, cost-efficiency, and so on.…”

“…A finite volume scheme for diffusion problem on non-rectangular meshes is introduced in (Li et al, 1980) which is the so-called nine-point scheme (NPS for short) on structured quadrilateral meshes. NPS has a simple and explicit expression of the flux, so it has been used for a long time in some radiation hydrodynamics codes, such as MARED and MARED-U (Ding et al, 2016). A similar version of NPS is the so-called diamond scheme (Coudière et al, 1999;Manzini and Putti, 2007;Bertolazzi and Manzini, 2007).…”

On the representation of dense plasma focus as a circuit element

“…It may be possible to deliver this energy to another kind of current-driven fusion load. Two examples of such wellresearched fusion load concepts are Z-pinch driven dynamic hohlraum [18,19] and the magnetized liner inertial fusion (MAGLIF) [20,21]. By combining the power density amplifying property of the plasma focus sheath with these or similar fusion loads, the attractive features of the DPF as a potential space propulsion concept would be retained without being plagued by uncertainties related to the fusion mechanism in the conventional Mather type plasma focus.…”