Numerical study of chiral properties of the wire helix

The authors investigate a wire helix with a view to determining its parameters for maximum chirality. The first step to determining the geometrical parameters of the wire helix that result in optimal equivalent dipoles is to use method of moments to determine the current distribution on the wire helix. The equivalent electric and magnetic dipoles are determined from the current distribution. The equivalent electric dipole is calculated by differentiating the current, which is expanded in triangular basis functions, and performing a summation over the product of the charge and the distance from the origin to the linear wire segments of the discretized helix. To calculate the dipole, the triangular current pulses are approximated by rectangles that are one-half in width but equal in area, thus simplifying the calculation of the cross product of the distance from the origin to the wire segment with the current. The result of the summation of the cross products yields the magnetic dipole, which is maximum for optimal clarity.<>