A thermal desorption spectroscopy study of hydrogen trapping in polycrystalline α-uranium

Abstract

The kinetics of hydrogen desorption from polycrystalline α-uranium (α-U) was examined using thermal desorption spectroscopy (TDS). The goal was to identify the major trap sites for hydrogen and their associated trap energies. In α-U six TDS adsorption peaks were observed at temperatures of 521K, 556K, 607K, 681K, 793K and 905K. In addition, the desorption was determined to be second order based on peak shape. The position of the first three peaks was consistent with desorption from UH3. To identify the trap site corresponding to the high temperature peaks the data were compared to a plastically deformed sample and a high purity single crystal sample. The plastically deformed sample allowed the identification of trapping at dislocations while the single crystal sample allow for the identification of high angle boundaries and impurities. With respect to the desorption energy associated with each peak, values between 12.9 and 26.5 kJ/mole were measured.

Helium self-trapping and diffusion behaviors in deformed 316L stainless steel exposed to high flux and low energy helium plasma

“…Figure 4 shows the helium desorption rate in the well annealed and 10% deformed@723 K annealed 316L specimens upon heating from 300 to 1073 K at a fixed heating of 1 K s −1 . It should be noticed that there is only one main peak at 450-940 K for the well annealed specimen in figure 4(a), which was fit using a Gaussian-shaped peak [39]. Figure 4(b) shows a very similar temperature range 450-940 K of the main peak in the 10% deformed@723 K annealed specimen, but with a higher amplitude and smaller stage, as indicated by the black ellipse near 805 K. The experimental data appear to be the summation of the helium desorption from the two trap sites.…”

Study of the Decomposition and Phase Transition of Uranium Nitride under UHV Conditions via TDS, XRD, SEM, and XPS

“…The technique of thermal desorption spectroscopy (TDS) is commonly used to monitor desorbed molecules from a surface when the surface temperature is increased. , It is especially useful to test the intermediate phase composition − and has been applied to study the decomposition of TiH 2 . However, the decomposition of uranium nitrides under nonequilibrium conditions using TDS has not yet been carried out.…”

Mechanism of surface uranium hydride formation during corrosion of uranium

“…If it is assumed that the hydriding reaction and surface sputtering was performed under extreme O-free conditions with sufficient sputtering depth, the detection results may merely indicate U and H. At those locations, the H occupied special sites, such as dislocations, grain boundaries, and twinning boundaries, or combined with metallic U. 30,31 Note that H may interact with U to form UH or a UH 2 cluster.…”