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Comment by pdonis | Hacker News Reader

Calling this "ignition" is a misnomer. The correct term, as given in the article (as opposed to the headline) is exceeding breakeven: more fusion energy output than energy input to the target.

"Ignition" means the reaction becomes self-sustaining and does not require any further input of energy to continue.

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And it was just that the after the initial laser pulse that triggered ignition there was no need to sustain it to continue to heat up the fuel to induce fusion.

The fact that this indeed was ignition was one of the main reasons why the fusion reaction itself was net positive.

> it was just that the after the initial laser pulse that triggered ignition there was no need to sustain it to continue to heat up the fuel to induce fusion

I don't see this anywhere in the article. Is there a better reference for what actually happened during the experiment?

No, this is ignition. However, the reason why this is a big deal is because it is scientific break-even.

The first time they achieved ignition was in August of 2021. See paper below:

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12...

They actually achieved both ignition and scientific breakeven. The resultant fusion heat helped produced significantly more fusion, not just relying on external energy (ie from the laser implosion).

> the reaction becomes self-sustaining

This is applicable only to continuously running reactions like in jet engines.

Which would also include any other method currently being pursued to achieve fusion, besides laser confinement. I'm guessing that the laser confinement community had to invent another meaning for "ignition" since the usual one would not be applicable to them.

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