Elliptic Helmholtz coil

Using the Biot-Savart law, we compute the magnetic field produced by steady currents that circulate in the same direction through two parallel ellipse-shaped loops. The calculation was performed along the axis that passes across the center of the ellipses. Then, we show that this arrangement produces a nearly uniform magnetic field for particular values of the semi-axis of the ellipse and the separation distance between the loops. This outcome is obtained as a consequence of numerically solving the second derivative condition. In addition, we show that, for the values reached, the elliptical Helmholtz coil produces results that are compatible with those of the classical circular Helmholtz coil. Finally, we show how the uniformity of the magnetic field varies for regions off the axis of the ellipses. The target readers of the paper are students pursuing physics at the intermediate undergraduate level.

Keywords:
Helmholtz coil; elliptic loop current; elliptic integrals; Biot-Savart law