Magnetization Modeling of Twisted Superconducting Filaments

This paper presents a new Finite Element numerical method to analyze the coupling between twisted filaments in a superconducting multifilament composite wire. To avoid the large number of elements required by a 3D code, the proposed method makes use of the energy balance principle in a 2D code. The relationship between superconductor critical current density and local magnetic flux density is implemented in the program for the Bean and modified Kim models. The modeled wire is made up of six filaments twisted together and embedded in a lowresistivity matrix. Computations of magnetization cycle and of the electric field pattern have been performed for various twist pitch values in the case of a pure copper matrix. The results confirm that the maximum magnetization depends on the matrix conductivity, the superconductor critical current density, the applied field frequency, and the filament twist pitch. The simulations also lead to a practical criterion for wire design that can be used to assess whether or not the filaments are coupled

Magnetization of coupled and non-coupled superconducting filaments with dependence of current density on applied field

In the LHC main magnets, persistent currents in the superconducting filaments determine the quality of magnetic field at an injection field. It is thus necessary to examine the magnetization of the superconducting filaments during production of the cable strands. The prediction of the magnetization can be based on numerical solutions obtained by using the finite element method. The magnetization curves of coupled and non-coupled superconducting filaments in two dimensions have been computed. In addition, the dependence of the current density according to the magnetic field have been taken into account . The effect of the space between the filaments has also been studied

Analytical & Numerical Modelings of Elliptical Superconducting Filament Magnetization

This paper deals with the two-dimensional computation of magnetization in an elliptic superconducting filament by using numerical and analytical methods. The numerical results are obtained from the finite element method and by using Bean's model. This model is well adapted for Low Tc superconductor studies. We observe the effect of the axis ratio and of the field angle to the magnetic moment per unit length at saturation, and also to the cycle of magnetization. Moreover, the current density and the distribution of the electromagnetic fields in the superconducting filament are also studied