Simulation of Hydrogen Isotopes Accumulation Processes in Materials in the Presence of Chemical Traps

The accumulation of hydrogen inside solids occurs in traps of a different nature. In addition to presence of hydrogen in interstitial sites, there are dislocation mechanisms of hydrogen storage, micropores and microcracks, sorption on the free surface of microdefects, chemical traps with the formation of hydrides and other compounds, both with matrix material and with impurities or components of alloys..

Numerical modeling of a low partial pressure water source for vacuum process

The presence of hard-to-remove water in the vacuum systems of research facilities or process lines is a problem in most cases. The ability of water to be easily absorbed and poorly desorbed by the surface of metal elements leads to the need for a long pump-down every time it opens to the atmosphere. It is necessary to get rid of water from the elements of the system by a thorough bake-up at temperatures of 400-500 K to achieve an ultrahigh vacuum [1-2]

Simulation of Hydrogen Isotopes Accumulation Processes in Materials in the Presence of Chemical Traps

The accumulation of hydrogen inside a solids occurs in traps of a different nature. The following things are known in addition to finding hydrogen in interstitial sites: dislocation mechanisms of hydrogen storage, micropores and microcracks, sorption on the free surface of microdefects, chemical traps with the formation of hydrides and other compounds, both with matrix material and with impurities or components of alloys. It is established that each type of trap has its own binding energy of hydrogen, which can vary from 0.2 eV for hydrogen gas in microdefects to several eV for hydrogen chemically bound in traps. Measurements of the distribution of hydrogen concentration dissolved in a solid body over binding energies provide a clue as to the understanding of hydrogen impact on mechanical properties and to the development of technologies for controlling the materials properties during their production and operation. The paper presents the results of simulation experiments on hydrogen saturation of materials in the presence of chemical traps. The proposed model, based on the numerical solution of the diffusion equation in the presence of irreversible capture, made it possible to describe the absorption process and determine the activation energies of hydrogen interaction with the material

Methodology of Corrosion Testing of Nuclear and Fusion Reactors’ Materals Using TGA/DSC and MS Complex Techniques

Nowadays, nuclear power is the best that humanity has for the production and supply for cheap electric and thermal energy. The development of nuclear power takes place in a rigid competitive struggle, both with the traditional technologies of electricity production, and with alternative (renewable) sources

Studies of two-phase lithium ceramics Li4_{4}SiO4_{4}-Li2_{2}TiO3_{3} under conditions of neutron irradiation

This work presents the preliminary experimental data on the study of gas release from two-phase lithium ceramics Li$_{4}$SiO$_{4}$-Li$_{2}$TiO$_{3}$ under neutron irradiation conditions. Experiments were carried out at the WWR-K research reactor (Almaty, Kazakhstan) for ∼4.3 days. The total neutron fluence during the irradiation was ∼1.8·10$^{19}$n/cm$^{2}$. In the course of irradiation, two experiments on ceramics heating during irradiation and two experiments with hydrogen isotopes (H$_{2}$ and D$_{2}$) supply into the experimental chamber with the sample were performed at a temperature of 680 °C and reactor power of 6 MW. During the entire irradiation, the gas composition in the continuously evacuated ampoule device with samples was recorded. The obtained dependences of the release of tritium-containing molecules and helium during the experiment were qualitatively analyzed