Cool Guys Don’t Look At Explosions
Rezwan Razani - October 11, 2013
The Official Report
The final word, posted after the government (and the labs) reopened. No mention of breakeven, which is too bad. I like the idea of breaking down “break even” into smaller breaks. It makes it more manageable. Otherwise it’s so “all or nothing.” The journey is more than the destination.
NIF Shot Achieves Record Yield
A NIF cryogenic layered deuterium-tritium (DT) implosion experiment on Sept. 28 generated about 5×1015 (five quadrillion) neutrons (about 14 kilojoules) of energy, almost 75 percent more than NIF’s previous record yield set on Aug. 13
All 192 NIF beams delivered 1.82 megajoules of ultraviolet light into the hohlraum laser entrance holes at a peak power of 395 trillion watts. Excellent target diagnostic data was obtained, and data analysis is under way.
The shot was the latest in a series of carefully designed ignition experiments that have increased yield more than five-fold since the first “high-foot” (high initial laser pulse) DT experiment last May.
Breaking Down Break Even
[Post Updated as of Oct. 13, 2013 - changed “scientific breakeven” to “fuel breakeven”]
What’s Fuel Breakeven? It’s a milestone on the road to fusion. It’s a big deal! Very cool! Here’s the BBC Report. And here are the milestones in order - a “breakeven breakdown” as it were:
- Fuel Break-even: defined as fusion energy exceeding the internal (thermal) energy contained in the fuel.
- Scientific Breakeven: generally defined as fusion energy exceeding driver energy on target (e.g., laser energy in the case of NIF)
- Ignition: fusion energy exceeding all energy losses in the fuel, meaning that it becomes a self-sustaining burn; known scientifically as the Lawson criterion
- True Energy Gain: fusion energy exceeding wall-plug energy used to create the burn; known as “engineering breakeven”
At first it was my understanding that the NIF achieved “scientific breakeven,” but I now understand that was not correct. To get scientific breakeven on NIF, the fusion energy would need to be around 2 MJ, which is the laser energy delivered to the target. What NIF got this time was around 14 kJ of fusion energy (i.e., 0.7% of 2 MJ). Thus, they are still around 100 times short of scientific breakeven according to the definition given.
Note that for the “breakeven breakdown” list above, the metrics will vary for different approaches to fusion (see Parameter Space of Fusion). The “scientific breakeven” definition above applies to laser driven ICF.
The fusion experiment tracker can start as a dynamic infographic showing the milestone points for various fusion approaches, and where the experiments are with respect to their personal paths.
But for now, let’s celebrate! Crack open a beverage and enjoy this song, dedicated to the tireless crew at NIF; and all the other folks who made this experience so cool, as noted below.
Thank You Fusion Team at NIF!
Congratulations! This song goes out to you, for conducting ridiculously cool experiments at insane temperatures and densities, explosions and implosions at a scale that defies - well, that are hard to look at (or to bear seeing) without an array of instruments.
Who’s got time to look at explosions? There’s cool guy errands that they have to walk to.
Keep walking, keep shining!
Too Cool to celebrate just a “milestone”
This song is also for the folks who are taking pains to downplay everything. Is it a breakthrough? A milestone? How should we feel about it?
“The more you ignore it, the cooler you look.”
Holla to JJ Abrams, featured in this song, and who was filming Star Trek at NIF last year. Thanks JJ, Chris Pine and Simon Pegg for including this important PSA about neutron cream in the DVD release.
Thanks for funding fusion - wait, it’s the taxpayer that funds fusion. Government, what’s up? Minute 1:54 to 2:02 goes to our fearless public servants on the hill, playing it a bit too chill, shutting themselves down, creating a series of awkward moments. For more on the budget and debt limit games, we go to CGP Grey.