Viewing a single comment thread. View all comments

BlueSkyToday t1_j1028nc wrote

Reply to comment by ItsAConspiracy in Nuclear fusion breakthrough: What does it mean for space exploration? by Gari_305

Still a very long way away from Engineering Breakeven.

1

ItsAConspiracy t1_j10c903 wrote

Yes, about one order of magnitude.

1

BlueSkyToday t1_j1p4udj wrote

Two orders of magnitude, and that's for a pulse reptation rate that you can measure with a calander.

1

ItsAConspiracy t1_j1q0n0g wrote

One. They put in about 2 MJ and got back 3 MJ, and the laser input energy was about 400 MJ. With 20% efficient lasers, you only need 10MJ into the lasers to get 2MJ in the laser beam. So a factor of five for breakeven.

If you're generating electricity, you've also got a factor of 3 for the heat cycle loss, so a 15X gain for engineering breakeven.

The pulse repetition rate is also due to the obsolete lasers. Modern petawatt lasers can do better than one hertz and are still improving (see my first link above).

1