New Approach To Confinement Replicated
It appears that we live at a time when political power and corporate financial interests are intimately tied to conventional hydrocarbon energy sources and control of the geographical regions that produce them. There is little motivation for change at the present, since those who pay the enormous and unnecessary physical and human price are not the ones who reap the profits. Nevertheless, the basic principles of physics and economics dictate that eventually an advanced technological society can only be powered sensibly by nuclear processes, eventually in the form of fusion.
The main problem to be overcome in achieving controlled fusion is that known as "confinement." Release of the enormous energy concentration available from causing two protons to fuse depends on getting them sufficiently close to each other, and keeping them there long enough, for the "strong" short-range force to bind them in a nuclear configuration. This entails overcoming their electrical repulsion, which is long-range, increases rapidly as they get closer, and is achieved by hurling the protons at each other fast enough to overcome the resistance--a bit like getting the body and wheel assembly of a car to "bottom" against the shock absorbers. The two traditional approaches are by using magnetic fields to contain a hot plasma of hydrogen fuel, or using energetic laser or ion beams to implode a succession of fuel pellets.
A reader by the name of Dave Durgee has called attention to a new method, repeated by several research groups in the US and Russia, known as "bubble fusion." A standing ultrasonic wave is used to help form cavitation bubbles of deuterated acetone vapor which then violently collapse, creating strong compression shock waves around and inside the bubbles. The internal shock waves impacted at the center of the bubbles causing very high compression and accompanying temperatures of about 100 million Kelvin. A more detailed account is available online at http://www.sciencedaily.com/releases/2004/03/040303080222.htm.
There was much optimism in the fusion community in the late 70s and 80s that the various experiments going on around the world would see some breakthroughs pointing toward commercial feasibility, but the funding and the political will to see it through were not forthcoming. Maybe the time simply wasn't right. Other factors perhaps dominated in deciding policy.
Note added, September 1, 2008. Pointed out by Tim Gleason.
The Washington Post, Saturday, July 19, 2008
Panel Finds Misconduct By Fusion Researcher
INDIANAPOLIS -- A Purdue University panel has found two instances of misconduct by a researcher who says he produced nuclear fusion in tabletop experiments.
Rusi Taleyarkhan made headlines in 2002 when he published a paper in the journal Science asserting that he had produced nuclear fusion by making tiny bubbles collapse in a liquid. The new report found misconduct in subsequent papers.
The committee said that, in a follow-up paper published in 2006 in Physical Review Letters, Taleyarkhan falsely said that his 2002 work had been confirmed independently. In fact, Taleyarkhan was extensively involved in the follow-up work, the committee found. The panel also found that in a pair of 2005 papers, Taleyarkhan added another person as an author, even though that researcher did not substantially contribute.
The committee did not investigate the 2002 paper itself. The paper was met with widespread skepticism, and other scientists have tried without success to independently reproduce Taleyarkhan's results.
Scientists have long sought a simple way to produce fusion in hopes of harnessing it as an energy source.