To clarify, when talking about the neutrons I wasn&#x27;t thinking about the radioactive waste problem, but about keeping the superconductor&#x27;s temperature low. I just took a look at the Iter schema and noticed that there is a &quot;blanket&quot; that covers the interior surface of the vacuum vessel exactly to absorb the neutrons. The vessel then has a water cooling system.<p>At this point, I was also wondering if you have any idea about how much of the heat transfer from the plasma to the vessel would be be through those neutrons (ie if it&#x27;s the main heat transfer medium).