Finite-elements numerical model of the current-sheet movement and shaping in coaxial discharges

Abstract

The movement and shaping of the current sheath in coaxial plasma guns is numerically modelled by means of a dynamic finite-elements representation. Numerical instabilities are avoided by a reshaping algorithm applied during the tracking of the current sheath acceleration. Improving upon older versions of the algorithm, the present model includes a delay model to treat the dielectric breakdown. Comparison against experimental measurements showed very good performances in representing the arrival times of the shock front at different filling pressures.

Statistical characterization of the reproducibility of neutron emission of small plasma focus devices

“…17,18 The third generation of models were based on a two-dimensional description of the current sheet, which is represented by a set of moving conical segments obeying the conservation equations of mass, momentum, and energy. 19,20 In plasma focus devices, neutron production presents a huge shot-to-shot fluctuation. These fluctuations are mainly a) atarisal@gmail.com.…”

Numerical Simulation of the Inductance Variation of a Plasma Focus Based in a Two-Dimensional Model

“…All these problems were successfully solved using the techniques discussed in [9]. Once a segment reaches the position of the outer electrode radius, it is assumed that the discharge current flows through the outer electrode.…”

“…For this reason, theoretical models of the CS cinematic that compare well with measurements of the timevarying component of the inductance have a better experimental support. In this paper, the 2-D numerical model CSHOCK [7], [9] is applied to indirectly determine the variable shaping of the CS in a PF device, using a set of electric diagnostics from which the variation of the gun inductance can be estimated.…”

Toroidal High-Density Singularity in a Small Plasma Focus

“…The evolution of the CS in PF-50J was modeled by means of CShock [4,5], which is a validated numerical code of PF discharges based in a two-dimensional model. The code showed great capabilities to predict the dynamics of the CS and was validated against a number of experiments in small PF devices.…”