Determination of effective recombination coefficient by thermodesorption method

• Desorption and diffusion activation energies interplay leads to several TDS-peaks.
• The effect of diffusion and desorption parameters on TDS-spectrum is illustrated.
• An approach to estimating desorption parameters is suggested.
• Integration of measurements is applied to noise resistance parameter identification.

The degassing by thermodesorption method (TDS) of structural material sample previously hydrogen saturated is considered. The mathematical model of TDS-experiment and parametric identification method are presented. The data for nickel and tungsten in numerical simulations are used. The two-peak problem and effect (“derivatives”) of diffusion and desorption parameters on the TDS-spectrum are illustrated. Diffusion coefficient is known but the recombination parameters on surface remain to be estimate. The estimation algorithm needs no special mathematical software and allows to scan a material in wide temperature range. Integral smoothing processing of measurements is applied in the algorithm to secure its noise resistance.