Reply To: turn heat into electricity

[asymmetric_implosion]

Kapton is ideal in many respects except for being a polymer. Polymer bonds are susceptible to damage under the intense UV of a plasma focus and the plasma facing during breakdown. The surface will turn into a powder mess that is mainly carbon. Carbon starts moving around the vacuum chamber and hurts the base vacuum. Tests conducted back in the 1990s showed that polymers hurt neutron yield and reduced the gas lifetime for folks that fire more than one shot on a charge of gas. I’ll try to find the reference but I don’t think I have it any longer. The ideal material can resist UV bombardment and plasma facing (alumina, diamond, or other ceramics). It would also need to resist mechanical shock (a polymer would work pretty well) and hold off high voltage (polymer or ceramic). I don’t think a perfect material exists. People have looked for this insulator material like tokamak folks have looked for a first wall material. It might be beyond our abilities at this time. The insulator is the common problem cited by technical reviewers for scaling up the DPF beyond 2 MA. Designs without an insulator exist but they have other problems. Where is unobtainium when I need it?