A choice of magnetic configuration of Torsatron/Heliotron devices based on Max(I) and Max(J)

A designing method to improve the plasma confinement in torsatron/heliotron devices is proposed. In order to reduce the direct orbit loss and the associated neoclassical transports, the condition of Max, which corresponds to minimizing the shift of the drift orbit from the magnetic surface, is required. The concept of Max is combined to reduce the anomalous transport due to the toroidally trapped particle modes. This can be done by tailoring the toroidal and helical ripples by external multipole components with the aid of the winding law of helical coils. Desired ripple profiles impose the constraints for the machine parameters. (author)