On concern of the study \cite{tzirtzilakis2000,oavalens1998}, the components of magnetic field of strength \(H_x\) and \(H_y\) on horizontal and vertical direction are as follows:
\[H_x(x,y)=-\frac{\gamma}{2\pi}\frac{x^2-(y+d)^2}{(x^2+(y+d)^2)^2}\]
\[H_y(x,y)=-\frac{\gamma}{2\pi}\frac{2x(y+d)^2}{(x^2+(y+d)^2)^2}\]
The magnitude \(\mid{H}\mid=H\)of the magnetic field is given by
\[\begin{equation}\label{eq:1}
\begin{aligned}
H(x,y)=[H_x^2+H_y^2]^{1/2}\\
=\frac{\gamma}{2\pi}(\frac{1}{(y+d)^2}-\frac{1}{2}\frac{x^2}{(y+d)^4})
\end{aligned}
\end{equation}\]