The EPSILON experimental pseudo-symmetric trap

Abstract

Within the framework of the Adaptive Plasma Experiment (APEX) conceptual project, a trap with closed magnetic field lines, the Experimental Pseudo-Symmetric Closed Trap (EPSILON), is examined. The APEX project is aimed at theoretical and experimental development of the physical foundations for a steady state thermonuclear reactor designed on the basis of an alternative magnetic trap with tokamak-like large β plasma confinement. A discussion is given of the fundamental principle of pseudo-symmetry, which a magnetic configuration with tokamak-like plasma confinement should satisfy. Examples are given of calculations in the paraxial approximation of pseudo-symmetric curvilinear elements with a poloidal modulus B isoline. The EPSILON trap, consisting of two direct axisymmetric mirrors linked by two curvilinear pseudo-symmetric elements, is considered. To increase the equilibrium β, the plasma currents are short-circuited within curvilinear equilibrium elements. An untraditional scheme of MHD stabilization for a trap with closed field lines by use of axisymmetric mirrors with a divertor is analysed. The experimental installation EPSILON-One Mirror Element (OME), which is under construction for experimental investigation of stabilization by divertor, is discussed. The opportunity for applying the ECR method of plasma production in EPSILON-OME in conditions of high density and low magnetic field is examined.

Flute mode fluctuations in the divertor mirror cell

“…This is to make a divertor magnetic field inside the GAMMA10 where the case of central cell divertor design was carried out by taking into account the plasma equilibrium. 19 Historically the equilibrium calculation has been carried out in various divertor mirror cells for isotropic pressure plasma, 20 for anisotropic pressure plasma 19,21 and for kinetic KruskalOberman stability theory with anisotropic pressure. 22 The theoretical study of flute mode stability by a magnetic divertor was done first by Lane et al 23 The subsequently the theory was extended by Pastukhov and Sokolov 24 by taking into account the nonparaxial magnetic filed line curvature and then was extended further more by Sasagawa et al 25 by including the anisotropic ion temperature effects.…”

Experimental Investigation of Plasma Flows From Open Trap With the Toroidal Divertor Under Ecr Discharge

“…На рис. 2 отдельно показана схема секции ЭЦР-источника плазмы, представляющей собой простую пробочную ловушку с тороидальным дивертором [9]. В так называемых диверторных катушках 2 направление тока противоположно току в катушках, создающих простое пробочное поле.…”

On the way to project EPSILON

“…It was proposed [4] to abandon space axis, rotational transform and MHD stabilization by magnetic well and return to Kadomtsev's trap based on the new idea of poloidal pseudosymmetry and MHD stabilization with plasma compressibility. According to the modern concept the maximum β through the equilibrium condition is determined by the topography of the magnetic field level lines (isomagnetics lines) on EMS [5].…”

“…It means that 'superbanana' transverse losses should be absent [7]. As the same type of PS should be kept when different parts of the magnetic system are joined, the important point is that because of the poloidal symmetry of the straight solenoid parts, the CREL's PS should be the poloidal one [4]. In that case all the isomagnetic lines, |B| = B = const on EMS should enclose the magnetic axis.…”