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(TH3/4) The Reversed Field Pinch as a Magnetically Quiet and Non Chaotic Configuration

D. F. Escande¹⁾²⁾, S. Cappello²⁾, F. D'Angelo²⁾, C. Marchetto²⁾, R. Paccagnella²⁾, D. Bénisti^2)
 
1) UMR 6633 CNRS-Université de Provence, Marseille, France
²⁾ Consorzio RFX, Padua, Italy

Abstract.  Recent progress in experiments open a path beyond the standard paradigm that a bath of magnetic turbulence is intrinsic to the reversed field pinch (RFP): quasi single helicity (QSH) states have been found in several RFP's. This motivates a thorough theoretical study of the single helicity (SH) states of the RFP which correspond to a laminar dynamo produced by a single mode, and an integrable magnetic field with good flux surfaces, a feature favourable to good confinement. Numerical simulations of visco-resistive MHD reveal a bifurcation from SH to multiple helicity related with temporal intermittency, which is ruled by the product of resistivity by viscosity. Furthermore a mechanism of magnetic chaos healing is shown to exist when the magnetic separatrix of the dominant mode of QSH states disappears due to a saddle-node bifurcation.

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