On the use of ion beams to emulate the neutron irradiation behaviour of tungsten

Abstract

Tungsten (W) is the primary candidate for use as the divertor armour in magnetic confinement nuclear fusion reactors. As such, the material will be plasma facing and subject to extremely harsh environments due to neutron and charged particle bombardment. To predict the in-service behaviour of tungsten during operation, ion beams are extensively used as a proxy for neutron irradiation damage. However, reproducing the complexities of radiation damage mechanisms as well as transmutation effects of neutron irradiations of W with single or multiple ion beams is still in its infancy and results can often seem contradictory. This review paper aims to collate and unite these disparate observations, with the aim of aiding the communities when moving forward to use the state-of-the-art in ion beam technology to emulate neutron damage in tungsten.

New insights into microstructure of neutron-irradiated tungsten

“…(Semi-)coherent precipitates were also observed by atom-probe measurements in W–Re alloys 53 . In this case, W–Re alloys with similar precipitation behavior as in the present case were already studied by several groups 11 , 33 , 43 , 44 , 56 , who reported circular-shaped σ-type and platelet-shaped χ-type precipitates. This agrees also with the binary W–Re phase diagram.…”

New microstructural insights into neutron-irradiated tungsten

“…(Semi-)coherent precipitates were also observed by atom-probe measurements in W-Re alloys 38 . In this case, W-Re alloys with similar precipitation behavior as in the present case were already studied by several groups 11,24,[41][42][43] , who reported circular-shaped σ-type and platelet-shaped χ-type precipitates. This agrees also with the binary W-Re phase diagram.…”

Re-evaluating ion and neutron irradiation data with calculated applicable arc-dpa

“…Tungsten is often used as the first wall material in fusion reactors, it is an ideal material to evaluate the impact of applying arc-dpa on irradiation data with different particles. Harrison reviewed the use of ion beams to emulate neutron irradiation on tungsten (28). Cavity densities of neutrons irradiated W from different neutron sources were compared with those of ions (H, He and W) irradiated W with various energies and temperatures.…”

“…As stated above, temperature has significant influence on recombination, thus data with most deviated temperatures are ignored (below 500°C or above 800°C). Cavities induced by irradiation, mainly gas bubbles and voids, are formed by elastic interaction between gas clusters and interstitial loops or SIA diffusion (28). The types of cavities in irradiation with various particles are different, but the cavity densities remain comparable.…”