Sandia staff in the Hydrogen Transport and Trapping Laboratory evaluate many features of the interactions between hydrogen and materials. In particular, the effects of hydrogen on mechanical properties can be strongly influenced by transport (or diffusion) of hydrogen in materials on the time scale of testing. Researchers in the Hydrogen Transport and Trapping Laboratory evaluate hydrogen effects using gas-phase permeation, thermal desorption spectroscopy (TDS), and local-electrode atom probe (LEAP) analysis.