Will fusion power ever become practical?

[wolf_meister]

There’s a saying that “fusion power is the energy source of the future - and it ALWAYS will be the energy source of the future”. It does seem that controlled fusion research hasn’t progressed much in the last few decades.
In the 1970’s, research was being done (and probably still is) with Tokamaks - super-powerful electromagnets which squeezed hydogen gas in an attempt to get the protons to fuse.
Also around that time, research was being done with lasers that would super-heat a deuterium-tritium pellet in an attempt to form a helium nucleus and a neutron. The problem was trying to get a laser beam to focus precisely on the pellet.
I’m sure we’ve all heard about “cold fusion” from about a dozen years ago which at first held some promise but proved to be non-existent when the methods were carefully scrutinized.
About a year ago, there was research being done on subjecting metallic filaments to huge current surges.
The latest research (I think) is being done in the area of cavitation. That is, bubbles in a liquid compressing the gas inside to cause fusion. (Seems like a miniature version of the Tokamak).

There you have it. Any thoughts on any new fusion research being done? Anyone think fusion power will ever be feasible?

[Whack-a-Mole]

It seems that scientists still think fusion power is achievable. I should probably say economicly viable fusion power. They have achieved controlled fusion reactions but so far the net energy input has been greater than the output. There is a new design concept that has yet to be built (see below). In the end the rewards are so huge that endless fiddling seems worthwhile. Further, the energy gained in fusion experiments has steadily risen since they started so some progress can be showneven if they haven’t made it viable yet.

Tokamaks and Stellarators

An attractive magnetic configuration is one that is passively stable and can be reliably sustained using little or none of the output power from the fusion plant. The success of the most widely studied magnetic fusion concept, the tokamak, has shown the advantage of bending the plasma into a toroidal, or doughnut, shape for achieving reactor-level plasma parameters for a short time. A crucial result from tokamak research was the experimental confirmation of a theoretically predicted self-generated “bootstrap current,” that flows in high pressure plasmas. This effect can greatly reduce the power required to sustain the magnetic field. The bootstrap current can be used to make the tokamak into a continuously sustained “advanced tokamak” configuration, but up to 20% of the plant’s output power would still have to be recirculated to drive active plasma controls needed to prevent the disruption of a tokamak plasma. This prompted fusion physicists to search for
configurations that would match the tokamak’s good performance and, by reducing the recirculating power requirements, would be even more attractive.

A solution was found in another well-studied toroidal concept, the stellarator, invented by Princeton astrophysicist Lyman Spitzer, Jr. Spitzer realized that a stable, three-dimensional plasma torus could be formed and sustained continuously without active plasma controls. The cross-sectional shape of a stellarator plasma depends on where the torus is sliced, while that of a tokamak, a two-dimensional torus, is always the same. The third dimension provides physicists with an additional degree of freedom which they can use to tailor the plasma shape to obtain attractive physical properties (see Figure 1).

SOURCE: National Compact Stellarator Experiment (PDF file)

[smiling_bandit]

They can actually get a net positive return now. Just not much, certainly not enough to make it worthwhile.

There has been substantial progress in the field, but problems keep croppping it. Its still viable, but it will take longer than previously thought. I expect to see one online at least late in my lifetime.