Energy and magnetic susceptibility of neutron matter

The magnetic susceptibility of neutron matter is calculated or estimated. The neutron spin polarization or the spin symmetry energy is calculated in terms of derivitives of the total energy with respect to the Fermi momentum. The results are obtained as a function of parameters expressing typical strength and range of neutron forces, and of the density. A ferromagnetic transition is found to occur at a Fermi momentum of approximately 2.5 fm-1 or a mass density of 9x1014g/cm3 corresponding to nuclear- matter densities expected in neutron stars. The method is, however, probably too simple to be reliable at such densities. (Auth.)