Part 2 of 2 Parts (Please read Part 1 first)
     All of the serious problems outlined in the first part of this article are complex challenges that have driven the development of new materials. One very important advance has been the development of high-temperature superconducting magnets. These are used on many fusion projects involving different reactor designs. These magnets have to be cooled below the boiling point of liquid nitrogen in order to be superconducting. This is much higher than the operational temperatures of many superconducting magnets.
     In a tokamak, these superconducting magnets are positioned only a few yards away from the extreme temperatures of the plasma in the reactor. This creates a huge temperature gradient. These magnets have the potential to generate much strong magnetic fields than conventional superconductors. This, in turn, can dramatically reduce the size of a fusion reactor. In addition, they may speed up the development of commercial nuclear fusion reactors.
     There are some materials that are designed to be able to deal with the multiple challenges involved in creating a practical fusion reactor. The most popular of these at the moment are reduced activation steels. They have an altered composition when compared to traditional steel alloys. This means that the levels of activation from neutron damage is reduced. Tungsten is also a preferred material.
    Sometimes, something that was originally seen as a potential problem is found to actually be a possible positive development. With respect to nuclear fusion research, tungsten fuzz is an example. This fuzz is a nanostructure that forms on tungsten when it is exposed to helium plasma during fusion experiments. At first, it was feared that this fuzz would be a problem due to the possibility of erosion. Now there are research programs for non-fusion applications for tungsten fuzz such as the use of sunlight to split water into hydrogen and oxygen.
     However, no perfect material for use in fusion reactors have been found yet. There are still several serious remaining issues in the quest of an ideal material. These include manufacturing reduced activation materials in large batches. The intrinsic brittleness of tungsten makes it difficult to work with.
     Despite the huge advances in the field of materials for fusion, there is a still a great deal of research and development that needs to be done. One major problem is the fact that researchers rely on proxy experiments to recreate potential reactor conditions. Once the experiments are carried out, the data generated must be combined. Often the size of the samples is very small and may not be fully representative. Detailed modelling work assists in the extrapolation of prediction of material performance. It would be preferable to be able to test the materials in actual fusion reactors in real world conditions.
    The pandemic has had a major negative impact on research into materials because it makes carrying out real life experiments more difficult. It is very important that researcher continue to develop and use advanced models to predict material performance. This can be combined with advances in deep learning in order to identify the key experiments we need to focus on and identify the best materials for the job in future reactors.
     The manufacture of new materials for fusion reactors has mostly been in small batches which only produce enough materials for specific experiments. Going forward, more companies will continue to work on the development of fusion reactors. There will be more programs working on experimental reactors or prototypes.
     At this stage, it is time to give more consideration to industrialization and development of supply chains. As the construction of actual prototype fusion reactors comes closer and the target of commercial nuclear fusion power plants approaches, the creation of robust large scale supply chains will be a huge challenge.