Observation of the Effects of Radially Sheared Electric Fields on the Suppression of Turbulent Vortex Structures and the Associated Transverse Loss in GAMMA 10

Abstract

Vortexlike turbulent structures in hot-ion mode plasmas with several keV are observed in the case with a radially produced weak shear of electric fields E(r). However, a strong E(r) shear formation due to a high ion-confining potential phi(c) production clears up these vortices together with plasma-confinement improvement and disappearance of both drift-wave and turbulencelike Fourier spectral signals. These findings are based on three-time progress in phi(c) in comparison to phi(c) attained 1992-2002. The significant advance of phi(c) is well extended in line with proposed potential-formation physics scalings.

Contained Modes In Mirrors With Sheared Rotation

“…Rotation shear has been found to stabilize high mode number, low frequency modes in mirror plasmas. [23][24][25] It is therefore unusual that sheared rotation should lead to waves with high mode numbers. However, in this case higher mode numbers have higher frequencies in the plasma frame, and we will show that they are not effec-tively damped by the velocity shear.…”

Neoclassical resonant transport of a mirror cell

“…The axial profiles of the magnetic field and the anticipated electrostatic potential are shown in Fig. 1͑d͒, where the axial profile of is assumed to be constant, except for the plug/ thermal barrier mirror cells [24][25][26][27][28][29][30] located at both ends of GAMMA10. The shape of the magnetic-flux tube and the names of the mirror cells in the nonaxisymmetric region are shown in Fig.…”

“…First we describe the basic equations to evaluate these quantities and the magnetic field of GAMMA10. 24 We adopt the paraxial approximation to the magnetic field with the flux coordinates ͑ , , z͒, where the equations of motion are written as ͑for example, see Ref.…”

Contained modes in mirrors with sheared rotation

“…[23][24][25] It is therefore unusual that sheared rotation should lead to waves with high mode numbers. However, in this case higher mode numbers have higher frequencies in the plasma frame, and we will show that they are not effec-tively damped by the velocity shear.…”