Nuclear Science User Facilities 70 has a high Curie temperature (950°C) and relatively high-saturation magne- tostriction (~70 ρ strains). Remendur is an alloy composed of approximately 49% iron, 49% cobalt, and 2% vana- dium. Because of its cobalt content, Remendur was not considered to be an ideal choice (due to concerns about the production of Cobalt-60 during irradiation). However, its successful prior use was deemed sufficient reason to warrant inclusion. Figure 2 shows the normalized ampli- tude for the Remendur transducer as a function of accumulated fluence. There is a generally decreasing trend, but signal recovery after temperature transients indicates that some of the signal attenuation is due to tempera- ture effects, in this case binding of the wire against the coil bobbin (see Figure 1 for transducer component diagram).As with the Galfenol transducer, increased noise after the first reactor restart post refueling may indicate an intermittent short in the drive/sense coil. Galfenol Galfenol is a relatively new alloy of iron and gallium (approximately 13% gallium). Galfenol is a member of the “giant” magnetostrictive alloys and has a very large saturation magne- tostriction (100–400 ρ strains). It also has an appropriately high Curie temperature (700°C). Neither of its constituent elements reacts strongly with neutron radiation.These factors made Galfenol a very appealing magnetostrictive material candidate. Figure 2. Remendur-element transducer-signal amplitude as a function of accumulated fast fluence.