Improvement of l=2 torsatron configuration with additional toroidal field

A method to improve the vacuum magnetic configuration of the l=2 torsatron with an additional toroidal field, Uragan-2M (U-2M), and its modification Uragan-4 (U-4) is suggested. In the torsatrons under study the center line of the helical winding pole obeys the law 2φ = - θ + αSINθ + βSIN2θ; α = 0.2618, β = -0.0171 (φ is the angular variable along the circular axis of the torus, θ is the angle in the poloidal cross-section of the torus). The analysis of the magnetic configuration has shown the presence of large island structures at t= 4/5, 4/6, 4/7 (t is the rotational transform over the device length). The magnetic surfaces were calculated in view of the real geometry of the conductors. (author) 4 refs., 5 figs