TY - JOUR
T1 - Dissolution-mediated trapping of deuterium in tungsten: high-flux, high-temperature plasma exposures
AU - Bakaeva, Anastasiia
AU - Terentyev, Dmitry
AU - De Temmerman, G.
AU - Lambrinou, Konstantza
AU - Morgan, T.W.
AU - Dubinko, Andrii
AU - Grigorev, Petr
AU - Verbeken, Kim
AU - Noterdaeme, Jean-Marie
N1 - Score=10
PY - 2016/7/9
Y1 - 2016/7/9
N2 - The effect of severe plastic deformation on the deuterium retention in tungsten exposed to high-flux low-energy plasma (flux ~1024 m−2 s−1, energy ~50 eV and fluence up to 5×1025 D/m2) was studied experimentally in a wide temperature range (460-1000 K). The desorption spectra in both reference and plastically-deformed samples were deconvoluted into three contributions associated with the detrapping from dislocations, deuterium-vacancy clusters and pores, respectively. As the exposure temperature increases, the positions of the release peaks do not change but the peak amplitudes are altered as compared to the reference material, due to the presence of dense dislocation networks in the plastically-deformed material. The appearance of blisters detected by scanning electron microscopy and the desorption peak attributed to the release from pores (i.e. deuterium bubbles) were suppressed in the plastically deformed samples at low-temperature exposures, but became the prevailing contribution above 700 K. The observed strong modulation of the deuterium storage in "shallow" and "deep" traps, as well as the reduction of the integral retention above 700 K, suggest that the dislocation network changes its role from "trapping seeds" to "diffusion channels" above a certain temperature. The conclusions of the present work are in line with recent computational assessment based on atomistic and mean field theory calculations.
AB - The effect of severe plastic deformation on the deuterium retention in tungsten exposed to high-flux low-energy plasma (flux ~1024 m−2 s−1, energy ~50 eV and fluence up to 5×1025 D/m2) was studied experimentally in a wide temperature range (460-1000 K). The desorption spectra in both reference and plastically-deformed samples were deconvoluted into three contributions associated with the detrapping from dislocations, deuterium-vacancy clusters and pores, respectively. As the exposure temperature increases, the positions of the release peaks do not change but the peak amplitudes are altered as compared to the reference material, due to the presence of dense dislocation networks in the plastically-deformed material. The appearance of blisters detected by scanning electron microscopy and the desorption peak attributed to the release from pores (i.e. deuterium bubbles) were suppressed in the plastically deformed samples at low-temperature exposures, but became the prevailing contribution above 700 K. The observed strong modulation of the deuterium storage in "shallow" and "deep" traps, as well as the reduction of the integral retention above 700 K, suggest that the dislocation network changes its role from "trapping seeds" to "diffusion channels" above a certain temperature. The conclusions of the present work are in line with recent computational assessment based on atomistic and mean field theory calculations.
KW - Dislocations
KW - Tungsten
KW - Retention
KW - Hydrogen
UR - http://ecm.sckcen.be/OTCS/llisapi.dll?func=ll&objId=20461900&objaction=overview&tab=1
U2 - 10.1016/j.jnucmat.2016.07.018
DO - 10.1016/j.jnucmat.2016.07.018
M3 - Article
SN - 0022-3115
VL - 479
SP - 307
EP - 315
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
ER -