Neutron spin quantum plasmas - Ferromagnetism as a relaxed state

It is shown that a ferromagnetic "minimum energy relaxed state" is accessible to a neutron fluid. We model the neutron fluid as a spin quantum plasma where the electromagnetic interaction is trough the magnetic moment of the neutron. The neutron ferromagnetism results from the macroscopic spin alignment that occurs due to a profound interplay between the classical and spin quantum vorticities carried by the charge-less neutron fluid. The simplest manifestation of a neutron superfluidity comes about by an exact cancellation of the quantum and classical vorticities to create a helicity free system.