4 ms·
> high-energy electrons that can punch a hole in the surrounding walls. What does it mean? Beta radiation can cause structural damage? Is it really a problem?
by red75prime 1y ago
> high-energy electrons that can punch a hole in the surrounding walls.
What does it mean? Beta radiation can cause structural damage? Is it really a problem?
- regularfry 1y agoThe electrons are high enough energy that they can damage the wall, yes. But also they're simply a route for energy loss from the plasma that you don't want. E.g. https://www.nature.com/articles/s41598-023-48672-7 https://www.nature.com/articles/s41598-023-48672-7
- red75prime 1y agoThanks! It's exactly what I needed, but felt too lazy to look up (which is uncharacteristic of me, but, well, why have forums if you have to look everything up yourself).
- jmyeet 1y agoYes. It's a significant problem for two reasons: 1. High energy particles destroy the container. Alpha particles, which are just Helium nuclei, are quite small and can in between metal atoms. Neutrons too. High energy electrons too; and 2. It's an energy loss for the system to lose particles this way. Magnetic confinement works for alpha and beta particles because they're electrically charged. Neutrons are a far bigger problem, such that you have fun phrases like "neutron embrittlement".
- pfdietz 1y agoIn a disruption in a tokamak, when the plasma collapses, the current in the plasma that goes around the ring decays. This creates an electric field as in a kind of accelerator called a "betatron". The electric field can accelerate runaway electrons to relativistic speeds. This beam can hit surfaces and melt holes, like a giant arc welder. https://www.jp-petit.org/NUCLEAIRE/ITER/ITER_fusion_non_controlee/Wurden_en.pdf https://www.jp-petit.org/NUCLEAIRE/ITER/ITER_fusion_non_cont...