MICROSTRUCTURAL EVOLUTION INDUCED BY LOW-ENERGY HYDROGEN-ION IRRADIATION IN TUNGSTEN

The microstructural evolution in tungsten during hydrogen ion irradiation with energies ranging from 0.5 to 8 keV at several temperatures between room temperature and 1073 K has been observed for the purpose of evaluating performance of tungsten during exposure to plasma and elucidating the underlaying mechanisms. It is shown that defect accumulation in tungsten is very small because of a high threshold energy for defect production by hydrogen and slipping out of dislocation loops to surfaces. This would lead to low hydrogen retention. These properties, however, may be degraded when the specimen purity is lower.