Analysis of Minor Hysteresis Loops for Neutron Irradiation and Plastic Deformation in Pure Fe

In situ magnetic measurements of pure polycrystalline Fe have been performed at 563 K during neutron irradiation in a 50 MW nuclear reactor. Magnetic properties that are sensitive to lattice defects were obtained from measurements of minor hysteresis loops with low applied fields less than 2 kA/m. The minor-loop properties show a monotonic increase with increasing neutron fluence up to 5times10¹⁹ cm^-2, which is due to the creation and growth of dislocation loops during neutron irradiation. The results of in situ measurements were compared with those of Fe single crystals at room temperature where dislocations were induced by tensile deformation