Heavy impurity transport in tokamaks subject to plasma rotation, NTV and the influence of saturated ideal MHD perturbations

Strongly peaked tungsten accumulation is a common feature of high performance plasma scenarios in JET with the ITER-like wall, particularly during MHD activity induced by m⁄n = 1⁄1 continuous modes. This study investigates the effect of 1⁄1 long living internal kink modes on heavy impurity transport in the presence of strong flows and NTV ambipolar electric field. A novel formulation which includes these effects is presented and applied in the VENUS-LEVIS code in order to follow tungsten ions in a saturated JET-like 1⁄1 internal kinked toroidally rotating plasma configuration. The synergy between 3D magnetic fields, strong flows and NTV is seen to cause tungsten accumulation in contrast to what is observed in similar axisymmetric configurations. Rapid inward transport of impurities in JET plasmas following the triggering of continuous 1⁄1 modes is explained by the work presented here, and we use the same theory to postulate why outward transport can occur in kinked ASDEX-U plasmas.

A Brief Review on Atmospheric Air Plasma

Atmospheric pressure air plasma is an attractive technology because it is easy to set up and handle, cheap, and safe. In this paper, a brief review on air plasma configuration and the results of air plasma is presented. One of the important properties of any plasma treatment is the generation of reactive atom species such as oxygen(O), nitrogen(N) also known as RONS, and other ions molecules particles. Air plasma has been found to have the same effect when treating surfaces. Surface modification, hydrophilicity, and decontamination effect were observed when materials are exposed to air plasma. The advancement of air plasma technology will improve the surface processing technology by reducing its operating cost.

1-D Modeling of the Screw-Pinch Plasma in PROTO-SPHERA

A simple steady-state model for a 3-species mixture (ions, electrons, and neutrals) in a screw-pinch plasma configuration is developed. The model is applied to the central plasma column of the PROTO-SPHERA experiment. Degree of ionization, azimuthal current density, and azimuthal ion velocity are calculated. Full ionization is found at plasma temperatures above 1.5 eV, with neutrals confined in an outer shell where radial plasma flow develops and drives both azimuthal current and azimuthal flow.