ELECTRICAL MEASUREMENTS ON THE GROWING SCALE ON ZIRCONIUM-TITANIUM ALLOYS

The corrosion rates of low-titanium zirconium alloys increased with titanmum content when exposed to water at 290 deg C or to 1 atm oxygen at 290, 350, 400, and 500 deg C. The scaling rate reached a maxmmum (approximately 3000 at 500 deg C and then decreased with increasing titanium content. Under the same conditions, pure zirconium and tmtanium had much lower weight gains, 10 and 4 mg/ dm/sup 2/ respectively. In oxygen at 500 deg C, the oxidation rate law was initially cubic or parabolic for alloys containing 3.75, 15.0, and 50.0 at.% Ti, and then changed to approximately a linear one. The transition times were 17, 7, and 54 min for the in the rate law and the rise in EMF and resistance appeared to be independent variables. The electrical changes were attributed to changes in defect structure, and the rate law ansitions were attributed to structural channges. The reilts provided an explanation for the maximum oxidation ite at 15 at.% Ti and for the differences in the influence of dditives on the corrosion rates of zirconium and titanium in high temperature water. Thc EMIF of the corrosion cell consisting of STAalloy /oxide! O/sup 2/! was a function of the resistance of the oxide layer. The 3.75 and l5.0 at.% Ti alloys had small EMF's and resistances inittally, but EMF and resistance increased appreciably and rapidly at times after the transition stage. The 50 at.% Ti alloy had a very small EMF which was relatmvely constant while the resistance showed a slight increase with time. (auth

Direct Mass Measurements to Inform the Behavior of <math display="inline"><mrow><mmultiscripts><mrow><mi>Sb</mi></mrow><mprescripts/><none/><mrow><mn>128</mn><mi mathvariant="normal">m</mi></mrow></mmultiscripts></mrow></math> in Nucleosynthetic Environments

International audienceNuclear isomer effects are pivotal in understanding nuclear astrophysics, particularly in the rapid neutron-capture process where the population of metastable isomers can alter the radioactive decay paths of nuclei produced during astrophysical events. The β-decaying isomer Sb128m was identified as potentially impactful since the β-decay pathway along the A=128 isobar funnels into this state bypassing the ground state. We report the first direct mass measurements of the Sb128 isomer and ground state using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. We find mass excesses of -84564.8(25)  keV and -84608.8(21)  keV, respectively, resulting in an excitation energy for the isomer of 43.9(33) keV. These results provide the first key nuclear data input for understanding the role of Sb128m in nucleosynthesis, and we show that it will influence the flow of the rapid neutron-capture process