3 research outputs found
MEP: a 3D PIC Code for the Simulation of the Dynamics of a Non-Neutral Plasma
No full textThe three-dimensional evolution of a pure electron plasma is studied by means of a newly developed particle-in-cell code which solves the drift-Poisson system where kinetic effects in the motion parallel to the magnetic field are taken into account. Different results relevant to the non-linear dynamics of trapped plasmas and low-energy electron beams are presented. [All rights reserved Elsevier]
Experimental investigation of coherent structures in a low-energy electron beam
No full textA sharp transition to a space-charge dominated regime is induced in a low-energy electron beam produced in a Malmberg–Penning trap by increasing the emission current of the source. The transition is characterized by the appearance of a region, around the axis of the beam, not accessible to beam electrons, and by the fast development of coherent structures in the remaining electron plasma, due to the sharp increase of local vorticity. The results are interpreted in the framework of a cold fluid drift–Poisson model, and using a three-dimensional particle-in-cell simulation code
Recent improvements in confinement and beta in the MST reversed-field pinch
No full textIn the general area of confinement improvement and concept advancement, recent results in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) include good confinement of both thermal and large-orbit ions and near doubling of total beta to 26% with deuterium pellet injection. Current profile control enables MST to reduce stochastic transport and achieve tokamak-like confinement. In standard RFP operation, substantial MHD tearing mode activity results in stochastic transport and an energy confinement time of about I ms in MST. Application of inductive current profile control reduces MHD activity and accompanying stochasticity, improving confinement by about a factor of ten. Previous work concentrated on electron confinement in improved-confinement RFP operation. Recent work confirms that ions are also well confined, and that high beta and improved confinement can be achieved simultaneously
