Part 2 of 2 Parts (Please read Part 1 first)
     In the face of these enormously complex challenges with respect to developing commercial nuclear fusion , there have been great advances in the development of new materials to meet these challenges. One of the most important breakthroughs has been the development of high temperatures superconducting magnets which are being employed in a number of different fusion research projects. They are able to maintain superconduction below the boiling point of liquid nitrogen which is widely available. This is around minus three hundred- and twenty-degrees Fahrenheit. While this is extremely cold, it is much warmer than the temperatures required by older super conducting magnets.
     Inside a tokamak, these superconducting magnets are only a few yards away from the high temperatures of the plasma. This creates a huge temperature gradient. These new magnets have the ability to generate much stronger magnetic fields than those generated by the old generation of superconducting magnets. This helps to significantly reduce the size of a fusion reactor. It is hoped that they will speed up the development of commercial fusion power reactors.
      There are some existing materials that have been designed to deal with the challenges of holding up under the conditions inside a tokamak. The most promising materials at the moment are called “reduced activation steels.” They have a different composition than traditional steels in which levels of activation from neutron damage are reduced. Tungsten is also being explored for use in tokamaks.
      Sometimes, somethings that is initially seen to be a a problem can actually turn out to be beneficial. This is the case with fusion research. One example of this is referred to as tungsten fuzz. The term fuzz in this context is a nanostructure that forms when tungsten is exposed to helium plasma during fusion research. At first, it was feared that this would cause erosion of the reactor vessel walls but now there is research being conducted into the possible use of tungsten fuzz for non-fusion research such as utilizing tungsten fuzz to assist in solar water splitting into hydrogen and oxygen.
     However, no material is perfect and there are remaining issues in the development of materials for fusion reactors. These include the manufacture of reduced activation materials at a large scale. The use of tungsten is problematical because it is intrinsically brittle. There needs to be improvement and refinement of existing materials.
     Despite the decades of research and the billions of dollars expended on fusion research there is still a lot of critical work that needs to be done. One major issue is the fact that it has been necessary to depend on proxy experiments to recreate the conditions that will be found inside a functional fusion reactor. Often very small data sets must be combined during this research. Detailed modeling work assists in the extrapolation of probably material performance. It would be much better to be able to conduct tests inside an actual tokamak at expected temperatures and pressures.
     The COVID-19 pandemic has had a major negative impact on materials research because it has made it more difficult to carry out real life experiments. It is very important that we continue to develop and utilized advanced models in the prediction of materials performance. This can be combined with advances in machine learning which will identify key experiments that are needed to identify the best materials for the job in future fusion reactors.
     The manufacture of new materials has previously been done in small batches. This produces only enough material to conduct experiments. In the future, there will be more projects in fusion research on experimental fusion reactors or prototype fusion reactors.
      Due to this situation, research is now approaching the point where there will need to be consideration of industrialization and development of supply chains for the components required for commercial nuclear fusion reactors. The development of robust large scale supply chains with be a great challenge.