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>Why did ITER decide to present Qplasma as the core metric This one is easy: they did not. https://www.iter.org/sci/Goals https://www.iter.org/sci/Goals You'

>Why did ITER decide to present Qplasma as the core metric This one is easy: they did not. https://www.iter.org/sci/Goals https://www.iter.org/sci/Goals You'll notice that the goal in question is the power output. Regardless, Qplasma is there because that is the plasma physicist's yardstick. Change it after 50 years because we're closer to ignition? For what purpose? I think the wording towards the end of the first goal could be better. That feels like headline bait, but it isn't why the goal was set. >most would consider the critical to decide closeness to commercial viability The goal of plasma physicists is to straight-line achieve fusion on the grid, not put on a song and dance. The straight-line path has nothing to do with making a number go up, but everything to do with developing plasma models in new regimes, performing materials studies, and just plain old doing it. ITER wasn't conceived as a demonstration power plant.

belter 5y ago
Problem is plasma physicists are being subsidized on their very meritorious endeavors, at the cost of 21 billion dollars. A paragraph like the one below, also from the reference you provided, is going to bite them bitterly: "ITER is designed to produce a ten times return on invested energy: 500 MW of fusion power from 50 MW of input heating power (Q=10). It will be the first of all fusion experiments in history to produce net energy." As ITER is supposed to start in 2025, and imagining a successful experiment running for 10 years. Adding to this the planning, and procurement process for a possible first device, one with the "real Q" above 1, then its clear it wont be here for at least another 50 years.
- willis936 5y ago
  It's true there will be a PR reckoning for that wording. I am not under the impression that those that greenlit ITER were deceived about the target performance metrics, which is the implied scandal. The scientists and engineers gave pitches to committees, the committees asked questions, the scientists answered honestly. Not everyone on those committees is clueless about plasma physics, as indicated by their informed questions (see the DoE FES subcommittee transcripts). Is this how we should decide to allocate society's taxed income? I don't know, but I don't think the funding of existentially critical research that requires expensive machines that only produce incremental knowledge should be on the chopping bloc every year. Regardless of whatever "well actually"s come about, the achievements of ITER should not be sidelined. If ITER is successful, it sets a very important bar for mega projects in the 2020s. It would be a valuable yardstick and a blueprint for a nuclear facility that has enormous subsystems for cooling and tritium processing. Thanks to HTS we might not need to make a machine much larger than ITER to hit the necessary performance metrics, but ITER is being made now, not in another two decades. Watch SPARC for now.
  - belter 5y ago
    Thanks for the replies.
  - belter 5y ago
    "Improbable Matter" posted a reply to Sabine video "In defense of "Q-plasma" - a response to Sabine Hossenfelder" https://youtu.be/KtqC8W0_Ups https://youtu.be/KtqC8W0_Ups
    - willis936 5y ago
      I had a conversation with him where I requested he make a Sabine response video in the comments of a previous video. I think he is a good communicator of plasma physics. His response didn't take the exact shape I would have taken, but I think his high level response will age better than my lower level points. I shared this video on HN when it came out. This kind of content doesn't inspire as many emotions, so it doesn't take off in the same way. That's a problem nobody has figured out how to grapple yet. ;) https://news.ycombinator.com/item?id=28964858 https://news.ycombinator.com/item?id=28964858

belter 5y ago

Problem is plasma physicists are being subsidized on their very meritorious endeavors, at the cost of 21 billion dollars. A paragraph like the one below, also from the reference you provided, is going to bite them bitterly: "ITER is designed to produce a ten times return on invested energy: 500 MW of fusion power from 50 MW of input heating power (Q=10). It will be the first of all fusion experiments in history to produce net energy." As ITER is supposed to start in 2025, and imagining a successful experiment running for 10 years. Adding to this the planning, and procurement process for a possible first device, one with the "real Q" above 1, then its clear it wont be here for at least another 50 years.

willis936 5y ago
It's true there will be a PR reckoning for that wording. I am not under the impression that those that greenlit ITER were deceived about the target performance metrics, which is the implied scandal. The scientists and engineers gave pitches to committees, the committees asked questions, the scientists answered honestly. Not everyone on those committees is clueless about plasma physics, as indicated by their informed questions (see the DoE FES subcommittee transcripts). Is this how we should decide to allocate society's taxed income? I don't know, but I don't think the funding of existentially critical research that requires expensive machines that only produce incremental knowledge should be on the chopping bloc every year. Regardless of whatever "well actually"s come about, the achievements of ITER should not be sidelined. If ITER is successful, it sets a very important bar for mega projects in the 2020s. It would be a valuable yardstick and a blueprint for a nuclear facility that has enormous subsystems for cooling and tritium processing. Thanks to HTS we might not need to make a machine much larger than ITER to hit the necessary performance metrics, but ITER is being made now, not in another two decades. Watch SPARC for now.
- belter 5y ago
  Thanks for the replies.
- belter 5y ago
  "Improbable Matter" posted a reply to Sabine video "In defense of "Q-plasma" - a response to Sabine Hossenfelder" https://youtu.be/KtqC8W0_Ups https://youtu.be/KtqC8W0_Ups
  - willis936 5y ago
    I had a conversation with him where I requested he make a Sabine response video in the comments of a previous video. I think he is a good communicator of plasma physics. His response didn't take the exact shape I would have taken, but I think his high level response will age better than my lower level points. I shared this video on HN when it came out. This kind of content doesn't inspire as many emotions, so it doesn't take off in the same way. That's a problem nobody has figured out how to grapple yet. ;) https://news.ycombinator.com/item?id=28964858 https://news.ycombinator.com/item?id=28964858