Riemannian geometry of twisted magnetic flux tubes in almost helical plasma flows

摘要: Riemannian geometry of curves applied recently by Ricca [Fluid Dyn. Res 36, 319 (2005)] in the case inflectional disequilibrium twisted magnetic flux tubes is used here to compute helicity force-free field case. Here application Lorentz tube tokamaks allows one obtain an equation that generalizes cylindrical tokamak a term contains curvature tube. Another example use done taking electron magnetohydrodynamics (MHD) fluid model (EMHD) plasma physics velocity helical and almost flows terms Frenet torsion thin tubes. The cases straight curved are examined. Second-order effects on arise poloidal component field, while appear toroidal component. fields computed t...