I have such mixed feelings about ITER. I hope we learn the things we want to from it, and that what we learn is good news. But ITER is very far from being a dem

I have such mixed feelings about ITER. I hope we learn the things we want to from it, and that what we learn is good news. But ITER is very far from being a demonstration of a practical power plant -- it's a science experiment first and foremost. (Well, it has really been an experiment in international government cooperation...) I'm concerned that fusion research could have an 'AI winter' if there are any problems with ITER. (Similar to what has happened to inertial fusion in the failure of NIF to achieve ignition.) On the bright side, I think Commonwealth's SPARC experiment has a chance of beating ITER to hit 'scientific' break-even (Q>1) -- although ITER should top out around Q=10-20, where SPARC is aiming for Q~4. (Q~20 is needed for a power plant.) The issue of 'disruptions' (rapid unscheduled disassembly of the plasma) has not been solved. ITER's construction was premised on the idea that we need it to be solved, so therefore it will get solved. The situation is very similar to that of self-driving cars -- avoiding 90% of disruptions seems pretty doable, but a percent or so happen without warning.(https://fusion4freedom.com/pdfs/Disruption-Risk-poster-Wurden-LAUR.pdf https://fusion4freedom.com/pdfs/Disruption-Risk-poster-Wurde...) I hope that people don't get the wrong idea about fusion from ITER. Fusion reactors don't scale down well, but they also don't have to be quite as large, slow, and expensive as ITER. Tokamaks only use about 10% of the available magnetic field pressure, which means about 100x less power density than is theoretically possible, for a given magnetic field strength. Also, ITER is limited by its superconductors to about 5T. REBCO superconductors could potentially triple that, which would increase power density 81 times. So, there is a ton of headroom to improve performance -- dealing with the outflux of power becomes the major issue, actually. Ultimately, fusion is a long way from market still. It's hard to innovate rapidly with devices that cost billions and have life-cycles of decades. Private enterprises are pushing down on those numbers, though -- that's where I'm pinning my hopes. Given that renewables are approaching grid parity, it looks like the goalposts will start receding before fusion even achieves net power production.