Nuclear fusion offers safe and sustainable power generation, without the production of long-lived radioactive wastes. Fusion core structural materials will be subjected to neutron fluxes greater than in current nuclear fission reactors, as well as extreme heat loads, and the search is on to find the most appropriate material. High Entropy Alloys (HEA’s) are a combination of several elements in similar amounts. Some HEA’s have a number of attractive properties, including radiation resistance. We have recently produced novel radiation damage resistant HEA’s for fusion, but identifying their crystal-structures using our laboratory equipment is difficult due to the similarity of the elements used. Therefore, in order to determine why our HEA’s are so resistant to damage, we need to characterise the alloys using neutrons to obtain a more accurate picture of the arrangement of the atoms.