The Columbia Stellarator Experiment

The Columbia Stellarator Experiment (CSX) project is an upgrade of the Columbia Non-neutral Torus (CNT), aimed at studying quasi-neutral quasi-axisymmetric plasmas. Coil manufacturing and alignment are critical for the successful operation of a stellarator device, as small misalignments can perturb the desired equilibrium. We conducted an extensive study on the effect of both manufacturing errors arising in coil winding modeled through a gaussian error distribution and rigid shifts on the growth of magnetic islands, iota profile changes, and quasisymmetric error. For expected resonances within the plasma equilibrium, we calculated the corresponding island width, providing insights into the magnetic topology's sensitivity to coil imperfections. By computing shape gradients of local coil perturbations, we can quantify the local sensitivity which can help determine the placement of current leads.