Magnetic Field Uniformity around Near-Helmholtz Coil Configurations

Abstract

The magnitude of the total magnetic field in the vicinity of a single round coil pair, a single square coil pair, and a trio of mutually orthogonal round coil pairs has been computer calculated, and the results graphically displayed as a series of contour lines. An investigation of the uniformity of field as a function of coil spacing indicates a distinct optimum near the Helmholtz spacing.

Magnetic Field of Coaxial Square Coils Enclosed With High-Permeability Material

“…General analysis of the magnetic field in Helmholtz coils and its uniformity in the absence of magnetic materials are well known, e.g. [6,8,9,20]). Analysis of sensitivity of Helmholtz coils on imperfections of design parameters are conducted in a number of papers, see e.g.…”

Comparison of calibration systems for magnetic field measurement equipment

“…Rudd and Craig [SI examined both Helmholtz coil shapes but did not present field equations nor did they compare the field uniformities of the two systems. Cacak and Craig [6] also examined both Helmholtz coil shapes but did not present field equations. They compared the region of field uniformity for the two Helmholtz designs only as a function of coil spacing.…”

Alignment of a vector magnetometer to an optical prism

“…Thus, any gradients introduced by the finite size of the coils will be sampled as the rotations are performed, based on this distance. Roughly, the radius of the coils should be at least 7 times the distance between the prism and magnetometer to achieve a precision of .1% 3,4 . Due to the geometric constraints of our apparatus, the prism is in one case 5 cm from the magnetometer, and so our smallest coil is a square 70 cm on a side.…”