Recombination coefficient of hydrogen on tungsten surface

The recombination coefficient is an important parameter for modelling hydrogen-metal interaction. It is responsible for hydrogen desorption from the surface of the metal and, therefore, significantly affects the hydrogen penetration into the metal, accumulation in and permeation through the metal. In the present work, the recombination coefficient of hydrogen (H) on tungsten (W) surface is examined. It is shown that the recombination coefficient of H on a clean W surface is extremely high which indicates the rapid desorption of the hydrogen molecule from the surface. Simulation using a high recombination coefficient well describes a wide range of experimental data of gas and ions interaction of hydrogen isotopes with tungsten. Proof of incorrectness of the Anderl's recombination coefficient is presented by comparing it with both theory and experiment. (C) 2019 Elsevier B.V. All rights reserved.