Atomistic modeling of the anomalous helium behaviors in vanadium

Ab initio calculations have been performed to clarify the primary behaviors of He atoms in vanadium and to generate the database for the development of the interatomic potential for V-He system within the framework of the"s-band"model.The calculated formation energies of the tetrahedral,octahedral and substitutional He defects,as well as those for He2,He3 and He2V clusters are reasonable when compared with relevant experimental results and ab initio calculations under the same conditions.The applicability of the present V-He potential for atomistic simulations to investigate the moving,clustering,and trapping of interstitial He atoms in vanadium are demonstrated.Similar to the results in iron and tungsten,the interstitial He atoms can migrate quickly in vanadium. However,He atoms aggregate into clusters with low binding energies,and the trapping of He atoms depend much on the pre-existing traps in vanadium.