jmc wrote:Hmm.. I'm not sure the human race can't afford to lose 20 billion dollars.
The world GDP per annum is about 40 trillion dollars.
ITER will spend 20 billion in 30 years.
Over that period the world will have earned 1200 trillion dollars.
Over the period of ITER's lifetime it will have spent 1.6e-5 of the world's GDP.
The WORLD can afford ITER easily. High energy physics may not be so lucky.
As the joke goes, practical fusion has been "just 10 years away" for the last 50 years. Current standards of energy technology are comfortable if imperfect. Current understanding of physics is effective if incomplete. There is no fundamental reason that the wealthy governments of the world need to continue to fund boondoggles that do nothing more than employ and amuse the physicists involved, or fund the large national laboratories for that matter.
Government funding has allowed many technologies to get the "leg up" they need to become commercial.
The second Vacuum tube computer built in the world was funded by the government (the US military to be precise) for 5 million of today's dollars. If it wasn't for primitive less-than-economic vacuum tube technology there would never have been the same drive to develop transistors.
Public funding (again from the US military) is what allowed the jet engine to be developed to the point where commercial investors could see an end in sight with respect to designing a competetive economic product, if jets hadn't already existed, I very much doubt private money would have been capable of designing them from scratch.
With regards to rocket technology, just recently we seem to be seeing the same phenomenon, where technology developed at great cost by the state has finally reached a point in maturity where private investors can actually see an economic product at the end of the tunnel and invest in it.
ITER will push plasma heating current drive and fuelling technologies to the very limit. Along with pushing the development of materials that can withstand has plasma fluxes and high energy neutrons.
If the ITER project was not planned IFMIF, would not be built. A facuility to investigate how materials can cope with high energy neutrons.
It may well be that the tokamak is not the route to economic fusion, but it is the most reliable route to burning plasmas. And I guarantee you, when another device is developed which is capable of economic fusion, they will utilize heat and fuelling technologies developed for ITER aswell as plasma facing materials and neutron shields developed by this programme.
The general public still ask the question "is controlled fusion possible?", while we in the community know that we've achieved high enough lawson triple products to be fairly sure that in principle a burning plasma DT device should be possible to build, many actually doubt even whether this can be done. If ignition can be reached, even inside a machine that can't hold together for long enough for remotely economic energy-production, then a major psychological barrier towards investment in and development of, nuclear fusion will have been overcome. I strongly believe that the success of ITER will have a positive impact in all areas of fusion research.
I agree with MSimon that you need a diverse approach to fusion development and as a scientist I too prefer the American approach with a wide range of different devices. But unlike MSimon, I'm not convinced that net energy can
be extracted from a device that costs 100 million pounds. There are thousands of different possiblities out there that are all crying for more funding, most of them would fail even with more funding, a few might well be better than tokamaks, but which ones? Because the other approaches are so far away from burning plasmas developing them is like drawing lots. We could spend the rest of eternity fiddling around with an endless number of low-energy non-ignitable plasmas and not funding any of them on to the next level.
Its true that Europe has ignored many other fusion techniques in favour of the tokamak and in some ways perhaps its good that the US maintains its diverse approach and does not become ITER obsessed, but I'm still glad that th EU has taken upon itself to build ITER, if nothing more it maintains the momentum of the fusion programme.