Beryllium acts as a neutron multiplier: .
The consumable Be is supplied either as a solid metal layer, or as part of the molten salt (such as FLiBe) coolant, or both. The right amount of Be in the path of D-T neutrons theoretically allows the fusion reactor to have a Tritium Breeding Ratio (TBR) greater than one. That’s the good news!
Speaking practically, this hasn’t been shown to work yet, and my understanding is that it is a must-have for commercial D-T fusion. Recycling tritium within an operating D-T fusion plant (and beyond that, increasing global T inventory to bootstrap / enable the world to bring new fusion reactors online) is one of the key remaining engineering challenges to viable D-T fusion power, and is an active research area. The greater-than-unity breeding side of the problem is only the first challenge; separating, extracting, and capturing the freshly baked tritium is also an unknown. But we’ve known about this problem for a while, and there is room for optimism; ITER, for example is planning to test 6 different designs for tritium breeding blankets.
Interesting, thanks.
One metacognitive behavior which I think you’re pointing to but I want to call out explicitly is something like, “I default-assume I should finish thinking the thought I’m thinking now. I should get to the end of the sentence.” (And then, before you know it, the next sentence begins…) Thinking is one example, but could apply to other verbs, reading/watching/doings as well.
Instead, it seems useful to experientially see that “stopping” can be “practiced” at any point, even before you get to the end of whatever it is. There is no need to finish the