Equilibrium and Fluctuations in a Plasma Confined in a Pure Toroidal Field

Abstract

Equilibrium and confinement in currentless toroidal devices is explained in terms of a flow-fluctuation cycle. The initial limiter equilibrium is shown to get fortified via fluctuation driven poloidal rotation and ponderomotive force in a self-consistent manner. The relevance of this to the recently proposed L-H transition theories is briefly discussed. [S0031-9007(96)00596-0]

Observation of Mode like Coherent Structures in Curved Magnetic Fields of a Simple Magnetized Torus

“…Various SMTs are operated worldwide, e. g. BETA at the Institute for Plasma Research in Bath, India [17], BLAA-MANN at the University of Tromsø, Norway [18], TORIX at theÉcole Polytechnique, Palaiseau, France [19], THORELLO at the University of Milano, Italy [20], and TEDDI at the University of Kiel, Germany [21]. Their purely toroidal magnetic field configuration lies between those of linear machines and the nested magnetic field lines of fusion devices.…”

Investigation of Plasma Equilibrium in the Saskatchewan Torus‐Modified (STOR‐M) during Alternating Current Operation

“…During zero cross over there is a further sharp increase in this speed. This would be sufficient to provide equilibrium to the plasma as discussed by Singh et al [19] Thus it seems that at least two important mechanisms are operational to provide the requisite equilibrium to the plasma during the current reversal phase, namely the short circuit effect of limiter and a self consistent poloidal flow. Although at the source of this larger flow is not clear.…”

“…The lifetime of plasmas measured in some currentless devices is larger than what can be accounted by Yoshikawa's theory. Hence additional mechanisms of rotational transform were sought and two such mechanisms were recently reported by, Rypdal et al [18] using the fluctuation driven cross field current and Singh et al [19] using the effect of poloidal flow and the generation of this flow by fluctuations. Both these theories explain the observed plasma life time in these devices.…”

Coherent to turbulence transition, enhanced flow and confinement in a simple toroidal plasma

“…9 In another set of experiments in BETA, with toroidal field set at one value, characterization of different regions with suitable instabilities has been done. 10 More recently, the role of fluctuations in driving the poloidal flow and achieving an "effective rotational transform" at a fixed magnetic fields has been elucidated, [11][12][13] though a magnetic rotational transform as in tokamaks does not exist in this device. A clear flowfluctuation connection and plasma filling in the entire radial domain has been demonstrated.…”