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Comment by donquixote25 | Hacker News Reader

I mean NIF has spent a majority of its life (11 years) seeing yields below 200 kj. Only in 2021 did it jump above 1 mj and in 2022 above 3 mj. If your definition of breakthrough is rapid improvement, I think this demonstrates it:

See below for previous yields of NIF shots. https://en.wikipedia.org/wiki/National_Ignition_Facility#/me...

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I realize this may be too complicated to explain in one comment, but as a layperson... can anyone summarize what they actually did to achieve this sudden gain in power? Like, what have they been doing for those 11 years? Upgrading the lasers, improving the optics, refining the design of the hohlraum, changing up the fuel? I know this is the cutting edge of physics and all, and maybe there's some DoE secrecy involved, but it's interesting that I haven't seen a single article yet attempt to summarize what changes were actually made in order to achieve the "breakthrough".

I don't think anyone specifically knows. If you ask the physics, they will point to changes (like pulse shape or component sizes) they made due to their increased understanding of the physics. If you ask the target design people, they will point to decrease fill-tube size and number of defects in the capsule. If you ask the facility, they will say their ability increase both power and control power delivery. Likely, it is a combination of everything.

The other point that has been mentioned to me is when you in the self heating regime, there are exponential returns on increasing "quality" of a shot.

Thank you!

What does "component sizes" and "fill-tube size" refer to, BTW? And the quality of a shot thing you mention in the last line? Sorry for all the questions, just curious

This powerpoint from last February has a good rundown in the context of the 1.35GJ shot from August 2021:

https://www.orau.gov/support_files/2022ssap/presentations/Da...

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