The Eddy Currents Calculation Based on the Least Square Algorithm for EAST

A method is developed to evaluate the current induced during startup in the vacuum vessel of EAST (Experimental Advanced Super conducting Tokamak) based on the least square algorithm. As the eddy currents distribution is axisymmetric and uneven, it is usually modeled using a thin shell approximation for the vacuum vessel. This problem is reduced to a circuit model by dividing the vacuum vessel into 40 units. Solving the circuit equation by means of the least square method, the eddy currents distribution can be got. Calculation results of the eddy currents distribution and measured results in EAST agree well, which confirms the correctness of the method and the models.