Determination of Detrapping and Trapping Rate Constants for Hydrogen Based on Experimental Thermal Desorption Spectra

We determined the detrapping and trapping rate constants of the reaction-diffusion equation for simulating thermal desorption spectra of hydrogen from experimental spectra of a small-size steel specimen. In the determination, the method of Choo and Lee was applied to the spectra of different heating rate, and the spectra of different specimen size were employed. The model incorporating the obtained rate constants was applied to the simulation of thermal desorption spectra of the small-size specimen. As a result, it was confirmed that the spectra were well reproduced. In addition, it was found that the model can simulate successfully the spectra of a larger-size specimen whose shape is different from the small-size specimen.