Helium retention and thermal desorption from defects in Fe9Cr binary alloys

In order to study the fundamental processes of helium retention and thermal desorption from the structural material of future fusion reactors, thermal desorption measurements were performed to investigate helium trapping from defects in binary Fe9Cr model alloys irradiated by 3 keV and 0.2 keV He ions. Interstitial type dislocation loops, vacancies and vacancy clusters were produced by irradiation with 3 keV helium ions, which acted as the sink trapped the helium atoms. Helium thermal desorption peaks from dislocations, helium-vacancies were obtained by thermal desorption spectroscopy at ∼540 °C, in the range from 205 °C to 478 °C, respectively. Simple first order dissociation kinetics are used to estimate the activation energies associated with the desorption groups. A sharp desorption peak was observed at ∼865 °C due to the BCC-FCC phase transformation for specimens under all examined implantation conditions.