Tritium Absorption on Carbon Nanostructures

In the present research study, we utilize a molecular dynamics simulation to investigate the possibility of using multiple graphene sheets for tritium control. The graphene sheets are equilibrated to temperatures of 10k, 100k, 300k, 600k, 900k, or 1200k in a simulation. After equilibration, the tritium atoms are made to travel toward the graphene sheet with uniform velocity. The velocities of tritium atoms are selected so that incident energies may be 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, or 500 eV. Reflection is shown to be the dominant interaction at low tritium incident energy, with a sharp decline in reflection rates as energy increases. For the case of a single layer of graphene, reflection rates reach a minimum around 5eV and steadily climbs as energy is increased to 10eV. Absorption rates are shown to increase with increasing tritium energy until energies are very high, around 5 eV. After 5 eV, absorption rates decrease as incident energy increases. Penetration rates of incident tritium atoms remain low until 5 eV, after which the rates increase steadily. Higher graphene equilibration temperatures yield higher absorption rates at low incident energies but lead to lower absorption rates at high incident energies. At low incident energies, reflection is favored more at lower temperatures, while graphene temperatures do not seem to affect reflection rates much at high incident energies. Lastly, penetration rates are consistently higher at higher graphene temperatures. The larger amount of energy present in the structure at higher temperatures allows for the C-C bonds in graphene to be more readily broken. The results obtained in this research study will be used to develop novel nanomaterials that can be employed for tritium control.