A neutron beam regulator has a magnetic coil configured around a neutron beam between the neutron beam source and a target. The magnetic coil may be used to contain the neutron beam and reduce the scattering of neutron. Neutrons have a magnetic moment and can be affected by exposure to magnetics fields. The magnetic coil may be used to modulate the neutron beam shape, intensity, velocity, direction and polarization. A magnetic coil may extend substantially the entire distance between a neutron beam source and a target. A magnetic coil may be a discrete magnetic coil having a separate power input and output from other magnetic coils and a plurality of discrete magnetic coils may be configured around the neutron beam. A magnetic coil may be a spiral magnetic coil and may be continuous, or extends substantially from the neutron beam source to the target.