While I am working on my next blog post, this excellent update on the state of fusion research from the Polywell Blog author John Smith shouldn't go unnoticed. He makes a strong case that the US is neglecting promising avenues towards self-sustained nuclear fusion as the ITER cost keeps on skyrocketing. This echoes a similar sentiment that I heard when visiting General Fusion. Nevertheless, I think quitting ITER completely, as John recommends, is unwise.
The US already only has observer status at CERN, so bailing on ITER would sideline the American physics community even more. Despite the cost overruns and irrespective of its commercialisation prospects, ITER will make for one of the most advanced testbeds for plasma physics. Should the US really shut itself out of having prime access to this machine once it is operational?
John's post provides an excellent round-up of the various approaches to fusion, and mentions the damage that cold fusion inflicted on the field, a story that deserves a separate article. But there is another plasma phenomenon that some hope could be exploited for nuclear fusion that goes unmentioned in John's otherwise exhaustive post. It shares some communality with the dubious cold fusion experiments: Abysmally bad replicability that severely damaged the reputation of one of the lead researchers in the field. This speculative approach to fusion was recently prominently featured in a surprisingly well researched gawker article (h/t Ed B.). It mentions some private outfits that are hanging their hat on sonoluminescence, and since the latter phenomenon is, after all, an actual plasma creating micro cavitation, these companies don't deserve to be lumped in with the more shady cold fusion hustlers.
However, it is quite apparent that none of these can produce neutrons at a significant rate, unlike PNL's High Yield Neutron Generator, an already commercially valuable technology. So there clearly is not much reason to get too excited about sonoluminescence unless one of the companies invested in this approach could replicate this feat.
On balance, the influx of private money into nuclear fusion start-ups is the story here, one that gives hope that humanity may find a way to break its self-defeating fossil fuel habit within our lifetime.