One embodiment of the invention includes a magnetic solenoid. The magnetic solenoid includes an elongated sidewall that extends along and surrounds a central axis between spaced apart ends. The central axis can include a center point that is approximately equidistant from the spaced apart ends. The magnetic solenoid also includes a conductive coil that extends along and conforms to the elongated sidewall and comprises a plurality of consecutive loops centered on the central axis. The plurality of consecutive loops can have a consecutive loop-spacing that is non-uniform along the central axis and having a substantial maximum spacing value at approximately the center point.