Slow positron beam study of highly irradiated RPV steel under proton and ion impact
Abstract
Ion irradiation combined with a slow positron beam could be used to evaluate irradiation damage correlated with embrittlement of nuclear materials. In this study, the evolutions of irradiation-induced defects in reactor pressure vessel steel exposed to 240-keV proton and 3-MeV Fe13+ ion irradiations with the same dose of 0.05, 0.14, 0.35, 1.37, and 2.26 displacements per atom (dpa) at a low temperature are investigated. Vacancy-type defects were produced by both proton and Fe13+ ion irradiation. The S parameters of proton-irradiated pure Fe and RPV steel increased with the dose and did not tend to a saturated value up to a high dose (2.26 dpa). The S parameters showed a saturated value at low doses after Fe13+ ion irradiation. This is because heavy ions can more easily produce larger open-volume vacancy-type defects than light ions at low dose.
- Publication:
-
Radiation Physics and Chemistry
- Pub Date:
- March 2019
- DOI:
- 10.1016/j.radphyschem.2018.11.011
- Bibcode:
- 2019RaPC..156..199S
- Keywords:
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- Defects;
- Ion irradiation;
- RPV steel;
- Slow positron beam