Radiation effects in beryllium used for plasma protection

Abstract

This paper reviews the literatureon beryllium,emphasizingthe effects of irradiationon essentialproperties. Swelling and embrittlement experimentsas a function of irradiationtemperatureand dose, and and as a function of neutron sp ztrum are described,and the resultsare quantified, where possible. Effects of impuritycontent are also reported,from which optimum compositionspecifications can be defined. Microstructural informationhas also been obtained to elucidatethe processescontrolling the propertychanges. The availableinformationindicatesthat berylliumdivertorscan be expected to embrittlequickly and may need frequent replacement.

Preliminary characterization of plasma-sintered beryllides as advanced neutron multipliers

“…Irradiation hardening up to 10,000 appm He ion irradiation shows no significant degradation as well as for the previous HIP Be 12 Ti samples from the previous study [3]. In our previous studies [3,11,12] the dependence of irradiation-induced microstructure and irradiation hardening and embrittlement on irradiation temperature was investigated for pure beryllium and for the previous HIP Be 12 Ti sample. The main reason for these phenomena would be their crystal structure [13].…”

“…Previous study examined the irradiation response of pure Be metal and Be 12 Ti fabricated by the powder metallurgy method including the HIP process (the HIP Be 12 Ti) regarding irradiation temperature dependence of microstructure development and mechanical properties, especially irradiation hardening and embrittlement [3,11,12]. In this part of this paper, we introduce the study of irradiation response of the plasma-sintered Be 12 Ti.…”

A survey of plasma facing materials for fusion power plants

“…Detailed numerical estimates have been made of the amounts of swelling to be expected, for various helium contents and temperatures. 27 Thermal shock tests for Be indicate that fast neutron irradiation increases brittleness. 11 Under normal first wall operating conditions, e.g.…”

Innovative tokamak DEMO first wall and divertor material concepts

“…For long burn DT fuel testing devices and DEMO, when the selection of chamber wall material is considered, the additional requirements of steady state operation and tolerance to radiation damage from neutrons and charged particles will have to be taken into account. A Be layer will not be suitable due to radiation damage (dimensional instability, gas production and excessive increase of T inventory due to transmutation) [2,3]. Similarly, a carbon divertor surface will not be suitable due to high physical and chemical sputtering rates, radiation damage (dimensional instability and reduction of thermal conductivity) of the material and the potential for large retention of tritium [3].…”