Corrigendum to “Helium apparent diffusion coefficient and trapping mechanisms in implanted B4C boron carbide” [J. Nucl. Mater. 517 (2019) 165–174]

The influence of irradiation induced vacancies on the mobility of helium in boron carbide

“…In p-type conditions, diffusion occurs via a dissociative mechanism, where He is occasionally trapped in vacancies as a substitutional impurity. In both cases the activation energy for detrapping is slightly higher 2 eV, which is compatible with very recents experimental results [49].…”

“…The results reported in this paper add a piece of information in order to interpret experiments where the mobility of He in irradiated materials is an important parameter. In a recent experimental work of one of us [49] B 4 C samples were implanted with He atoms, then annealed and He profiles were extracted through Nuclear Reaction Analysis (NRA). An activation energy of E a = 2.03 ± 0.18 eV was obtained following a classic Arrhenius analysis for the intra-granular diffusion of He atoms in boron carbide.…”

Initial investigation of B4C–TiB2 composites as neutron absorption material for nuclear reactors

“…Misfits in the lattice structure of the interfaces contain plenty of open volume [32], which provides adequate free space for the deposition of irradiation-induced point defects (e.g., vacancies, interstitials, transmuted elemental atoms) [33]. Owing to the high binding energy between vacancies and He atoms (~ 2 eV [27,28]), the open volume of interfaces can act as efficient trapping sites for He and preferential nucleation sites for He bubbles [8,9,34]. Therefore, once the He atoms are captured by the interfaces, they cannot easily be released within the temperature range investigated in this study.…”

“…The TEM resultsshow that the interfaces of B 4 C and TiB 2 are effective trapping sites for He atoms and nucleation sites for He bubbles. Note that in a fast neutron reactor, the ballistic damage induced by energetic neutrons scattering and the nuclear reaction products (e.g., He, Li) scattering are much higher than the sole He ions implantation, this leads to a higher vacancy/He ratio and the possible consequences on the defects dynamics[28].Overall, this study provides a synthesis method for fabricating neutron absorption materials for the application in nuclear reactors. The special property-optimized B C-TiB 2 composites with designed microstructure exhibit a better resistance to disintegration under irradiation and in the thermodynamic environment of nuclear reactors.…”

“…The main feature of the composite is a highly thermally conductive cage-like TiB 2 network that encapsulates conventional B 4 C matrix grains. TiB 2 has a high melting point (3498 K), exceptional hardness (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35), highly thermal conductivity, excellent wear resistance, a low thermal expansion coefficient (4.6 × -6 K -1 , which is almost the same as that of B 4 C, 4.5 × 10 -6 K -1 ), and a high oxidation resistance [14][15][16][17][18]. Owning to the inimitable characteristics of…”