اندماج نووي
Nuclear fusion, the combining of the heavy isotopes of hydrogen, also has the potential to produces large quantities of neutrons. Small scale fusion systems exist for (plasma) research purposes at many universities and laboratories around the world. A small number of large scale nuclear fusion experiments also exist including the National Ignition Facility in the US, JET in the UK, and soon the ITER experiment currently under construction in France. None are yet used as neutron sources.