Magnetic fields produced by non-concentric and non-coplanar currents in circular loops

Abstract

A numerical calculation for the stationary magnetic field produced by arrangements of non-concentric and non-coplanar loop current circuits is presented. The calculation is done by superposing the solution of the magnetic field produced by a set of loops with constant currents that mimic two and three-dimensional systems. In the three-dimensional cases, this is achieved by rotating the magnetic field produced by the non-coplanar loops and adding all the contributions at any arbitrary point in the space. We report the case of two coplanar non-concentric loops that do not overlap and two concentric coplanar rings with different radii carrying currents in the same and opposite directions. Then we consider two non-coplanar rings that are tilted by an angle. More complicated systems consist of a set of loops forming a semi-doughnut. As an extension, we add at the two ends of this system concentric loops to form a horseshoe magnet with a circular cross-section and analyze the results as a function of its geometric characteristics. We can calculate the solutions of the magnetic field in all the space and plot their field lines using a technique that makes use of the Runge–Kutta fourth-order method. In all the cases we plot with different colors the field lines to give information on their strength.