Measurement of the line tying current pattern in the proto S-1/C tilt stabilizing structure

The Proto S-1/C spheromak device has been used in the past few years to study various tilt stabilization techniques. As the importance of the line tying effect became recognized, a more thorough understanding of the underlying physics was desired. Complex computer modeling of spheromak tilting dynamics using 3-D resistive MHD supported the experimental observations of the effectiveness of line tying, but a true insight into the basic physics is needed. The most recent evolution of the Proto S-1/C stabilizers have allowed easy measurement of the perturbed current pattern during tilting, and the line tying currents have been identified. The experimental patterns are found to be consistent with a proposed simple physical model of line tying, and provide a better understanding of the power and pitfalls of relying on line tying for the enhancement of tilt stabilization