Dr Daniel López-Bruna (EsLNF)
The relaxation of the constraint of periodicity imposed by the external confining magnetic field coils in a nominally 4-field period Helias Advanced Stellarator configuration produces weak periodicity-breaking deformations of the plasma. The corrugations are driven by the interaction of the pressure gradient with the magnetic field line curvature and correspond to saturated ideal magnetohydrodynamic interchanges with a mode structure dominated by nonresonant $m=1$, $n=\pm 1$ Fourier components. Very similar low order mode number oscillations are observed in the 4-field period TJ-II Heliac stellarator. The conditions of quasi-isodynamicity of the Helias reactor system investigated are not significantly altered by the periodicity-breaking distortions.
|Country or International Organization||Spain|
Dr Wilfred Cooper (ChEPFL)