Progress in Fusion Simulations

While funding remains a critical factor, progress has been made in recent months in focus fusion research. Robert Terry of Naval Research Laboratory, who is collaborating with Lerner, has further developed techniques that can be used to simulate the complex process with in a dense plasma focus.

His new technique consists of creating in the simulation “fluid particles” which have the behavior of entities within the focus, such as the vortex filaments that form when the current pinches itself together. The physics of such vortex filaments is quite well-known, and their behavior can be programmed into the “fluid particles” that represent them in the simulation. Such a technique is far more powerful than simply computing the paths of the individual electrons and ions that make up the filaments. By analogy the new technique is like meteorologists tracking a hurricane vortex as single particle, with complex behavior, rather than tracing the paths of individual packets of air.

Lerner is beginning a new, much more limited, simulation of the fusion reaction within the plasmoid that is the key to DPF functioning. A previous simulation was zero-dimensional, treating the plasmoid as a homogenous sphere. The new simulation will be one-dimensional, modeling the core of the plasmoid as uniform along its length, but varying in density and magnetic field in the radial direction.