COUPLING CURRENTS IN RUTHERFORD CABLES UNDER TIME VARYING CONDITIONS

A new network model is presented to simulate fully transposed Rutherford cables under time varying conditions. The intrinsic properties of the cable and the external applied conditions can be changed spatially. Several statistical distributions of the contact resistances are built in to investigate local differences in the coupling loss and in the eddy currents. The average loss is rather independent of a resistance distribution but locally both the loss and the eddy currents can increase significantly. The self field distribution of the cable is included resulting in a saturation of the strands which depends on the relative direction between the magnetic field, the field sweep rate and the transport current. Furthermore, mutual inductances between strands are introduced which enables the use of the model for nonstationary problems (e.g.: the response of the coupling currents to changes in the transport current and/or changes in field sweep rate, including high frequency calculations). Time constants can be calculated for both the coupling currents in the strands as for the local and global dissipation.