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'Star In a Jar' Fusion Reactor Works, Promises Infinite Energy (space.com)
An anonymous reader quotes a report from Space.com: For several decades now, scientists from around the world have been pursuing a ridiculously ambitious goal: They hope to develop a nuclear fusion reactor that would generate energy in the same manner as the sun and other stars, but down here on Earth. Incorporated into terrestrial power plants, this "star in a jar" technology would essentially provide Earth with limitless clean energy, forever. And according to new reports out of Europe this week, we just took another big step toward making it happen. In a study published in the latest edition of the journal Nature Communications, researchers confirmed that Germany's Wendelstein 7-X (W7-X) fusion energy device is on track and working as planned. The space-age system, known as a stellerator, generated its first batch of hydrogen plasma when it was first fired up earlier this year. The new tests basically give scientists the green light to proceed to the next stage of the process. It works like this: Unlike a traditional fission reactor, which splits atoms of heavy elements to generate energy, a fusion reactor works by fusing the nuclei of lighter atoms into heavier atoms. The process releases massive amounts of energy and produces no radioactive waste. The "fuel" used in a fusion reactor is simple hydrogen, which can be extracted from water. The W7-X device confines the plasma within magnetic fields generated by superconducting coils cooled down to near absolute zero. The plasma -- at temperatures upwards of 80 million degrees Celsius -- never comes into contact with the walls of the containment chamber. Neat trick, that. David Gates, principal research physicist for the advanced projects division of PPPL, leads the agency's collaborative efforts in regard to the W7-X project. In an email exchange from his offices at Princeton, Gates said the latest tests verify that the W7-X magnetic "cage" is working as planned. "This lays the groundwork for the exciting high-performance plasma operations expected in the near future," Gates said.
1. Tokamak -- has never underperformed models
2. Stellarator -- appears like it will work.
3. MagLIF -- Experiments are following model predictions.
The reason why magnetic fusion doesn't work yet is because of the budget needed to build a large enough reactor.
The reason laser fusion hasn't worked is because the models have been failing. Basically using a neodymium laser works in computer modeling but in real life it sucks. In fact a laser beam itself is too coherent.
Anyway, we still have a track to fusion it is X number of years away because ITER was supposed to be built in 1984 and now it's scheduled for 2035 because of budget reasons. Tokamak has always worked as predicted or better.
MagLIF is probably the easiest and cheapest route to fusion. Lockheed seems to have a good approach too.
The key part is omitted, this is a new version (of an old idea) of a field arrangement that is believed to confine the plasma better:
"The stellarator is different from the other toroidal magnetic surface concepts in that both the toroidal and the poloidal field components—which together create the magnetic surface topology—are created from currents in external coils. In the tokamak and the reversed-field pinch2, a strong toroidal current driven within the plasma is needed to generate the poloidal magnetic-field component. The stellarator’s lack of a strong current parallel to the magnetic field greatly reduces macroscopic plasma instabilities, and it eliminates the need for steady-state current drive. This makes it a more stable configuration, capable of steady-state operation. These are important advantages for a power plant....The stellarator was invented by Lyman Spitzer in the 1950s (ref. 3). So why did it fall behind? And why do some believe that it is about to have a comeback?"
given that among the authors of the Nature paper are R. C. Wolf and C. Biedermann. This Wolf-Biedermann project will of course produce high energy neutrons which must leave magnetic confinement in order to provide useful energy. When these neurtons strike metallic shielding material in the walls of the "stellerator" they generate radioactive elements via the process called neutron activation. And these radioactive elements release gamma rays, alpha and beta particles, x-rays and other components collectively referred to as radioactive waste. So when this ad from the 1950s claims there will be no radioactive waste, it is not telling the truth.
"He took a duck in the face at 250 knots." -- William Gibson, Pattern Recognition
And does nothing to dispel the belief that fusion is fifty years in the future. And it has been fifty years in the future for the last fifty years. Given the recent success of renewables and advancing battery and storage technology, fusion is unlikely to ever see the light of day. The funding will soon be diverted into military spending for the coming global war between populist fascist states in any case. Who needs science and experts when there is a war against immigrants and foreigners to be fought.
Facts are history now plebs have politics for religion on social media.
it has been fifty years in the future for the last fifty years. Given the recent success of renewables and advancing battery and storage technology, fusion is unlikely to ever see the light of day.
Actually it has been 50 years in the future for more like the past 70 years. However while fusion power is nowhere close to infinite and, given the complexity of the reactor unlikely to be cheap, it would still be very worthwhile to have. Renewable energy sources have limited capacities and require a lot of area which means they have a limited ability to fill our energy needs so while their capacity can certainly be increased going all renewable is unlikely any time soon.
This may not be much of an issue in North America but in places like Europe finding enough area for all the solar, wind and wave power needed is unlikely to happen because people do not want to live next to a wind turbine or even in sight of one. Building wave power schemes has similar issues as people complain about the environmental impact. Battery technology is also a very long way from being able to cope with the massive storage requirements to counter the variability which would then require enormous numbers of pumped storage schemes. So having a pollution free alternative to coal and gas will still be extremely useful.