  A device consisted of a set of circular rings, the centers of which lie on an
axis, behaves like a solenoid when the ratio of its radius and distance between
two successive rings is greater than one. As this ratio decreases, the device
deviates a lot from the solenoid behavior.In the same way, a diffraction
phenomenon for magnetic field appears when currents of random direction flow
through the rings. This phenomenon demonstrates a critical behavior. Thus an
extension of diffraction phenomenon can be done beyond the classical wave
diffraction. A possible application of this device could be the diffraction of
electronic beams.
