Applicability of the ferromagnetic resonance for neutron irradiated degradation in the reactor pressure vessel

The change of the neutron irradiation effect has been investigated in the nuclear reactor pressure vessel (RPV) steels which differ in steel refining process. We were employing the ferromagnetic resonance (FMR) technique and hysteresis loop to study the magnetic properties. Both resonance fields and line widths increased but its FMR intensity decreased with the irradiated specimens. The present work shows that the FMR technique can be used to estimate material degradation of the reactor vessel steel.