FIG. 4. Analysis of the build-up of lattice defects during irradiation. (a) DXA analysis of the initially segregated HEA at dierent irradiation doses. (b) The same for a Ni sample. Empty space represents the perfect FCC lattice; the structures do not collapse during irradiation. Green lines indicate h112i partial dislocations, turquoise lines indicate a Frank loop, pur- ple lines belong to stacking fault tetrahedra, and red surfaces enclose defects that cannot be recognized by DXA. Videos of these simulations can be found in the supplementary material (CuNiCoFe-ordered-DXA-during-irradiation.avi and Ni-DXA-during-irradiation.avi). (c) A closer look at those red regions reveals that they represent vacancies and vacancy clusters. In (d), a plot of the concentration of defective atoms as identied by CNA is shown as a function of the irradiation dose. In agreement with the DXA results, we can see that the HEA quickly reaches a high defect concentration that saturates around 4 %. These defects consist mostly of vacancies and small dislocation networks. Pure Ni builds up the defect concentration more slowly. At rst|similar to the HEA|vacancies and small dislocation networks appear, then these start disappearing in favor of stacking-fault tetrahedra and a Frank loop.

FIG. 4. Analysis of the build-up of lattice defects during irradiation. (a) DXA analysis of the initially segregated HEA at
dierent irradiation doses. (b) The same for a Ni sample. Empty space represents the perfect FCC lattice; the structures
do not collapse during irradiation. Green lines indicate h112i partial dislocations, turquoise lines indicate a Frank loop, pur-
ple lines belong to stacking fault tetrahedra, and red surfaces enclose defects that cannot be recognized by DXA. Videos
of these simulations can be found in the supplementary material (CuNiCoFe-ordered-DXA-during-irradiation.avi and
Ni-DXA-during-irradiation.avi). (c) A closer look at those red regions reveals that they represent vacancies and vacancy
clusters. In (d), a plot of the concentration of defective atoms as identied by CNA is shown as a function of the irradiation dose.
In agreement with the DXA results, we can see that the HEA quickly reaches a high defect concentration that saturates around
4 %. These defects consist mostly of vacancies and small dislocation networks. Pure Ni builds up the defect concentration more
slowly. At rst|similar to the HEA|vacancies and small dislocation networks appear, then these start disappearing in favor
of stacking-fault tetrahedra and a Frank loop.