Investigation of ITER candidate beryllium grades irradiated at high temperature

TEM study of impurity segregations in beryllium pebbles

“…High-temperature neutron irradiation experiments of beryllium materials and subsequent investigations of their microstructure by transmission electron microscopy (TEM) have been carried out already [3][4][5][6]. This study focuses on analysis chemical composition and spatial distribution of impurity particles and their possible influence on the formation of fracture surfaces or crack propagation in beryllium.…”

“…Commercial beryllium contains numerous impurity elements, such as Fe, Mn, Cr, and U, whose concentrations may vary for different production heats [4,5,7] properties and microstructure use the impurity content data from data sheet of the manufacturer. The distribution of these elements and their influence on mechanical properties was not studied properly in the past.…”

Irradiation effects in beryllium exposed to high energy protons of the NuMI neutrino source

“…The observed shift of the fracture mechanism from transgranular cleavage to grain-boundary cracking is a known radiation damage effect in beryllium and has been observed under neutron [64] and ion [17] irradiations. It is generally considered that the determining mechanisms here are helium segregation to grain boundaries at high temperature irradiations and the strengthening of the beryllium matrix by point defect clusters and/or nanometric gas bubbles at low temperatures [14][15][16][17].…”

“…In the case of beryllium, most attention is currently paid to the gas transmutation products hydrogen and helium. Helium accumulation from either direct ion implantation or as a result of neutron-induced transmutation has been shown to result in significant changes in the properties of beryllium over a wide range of temperatures [14][15][16][17]. Such effects include those from the formation of nanosized helium bubbles, which is believed to be one of the main hardening mechanisms of beryllium irradiated at low temperatures [17]; additionally, helium assisted anisotropic swelling at low temperatures and helium bubble formation at grain boundaries at high temperatures may lead to grain boundary weakening and drastic loss of ductility [15,18].…”

Atomistic simulations of He bubbles in Beryllium

“…Beryllium (Be) has attracted a lot of attention in the context of applications that involve radiation [1][2][3][4][5][6][7][8] because of the excellent radiation response properties of this material, such as the low atomic number, low neutron-capture cross-section, and high neutron scattering cross-section. For example, Be is used as a neutron moderator in nuclear fission reactors [1][2][3] and it is being considered for the first wall of the ITER nuclear fusion reactor [3][4][5]. Be has been also used as the target material and beam window in high-energy particle accelerators [6][7][8].…”