A NEW FUSION REACTOR TRIES AGAIN

Keeping hope alive after decades of false starts and failed attempts, scientists are firing up the latest redesign of a fusion energy reactor.
Nuclear fusion smashes together hydrogen isotopes under such high temperatures they meld into one particle. Fusion releases vast energies; the sun is a giant, continuous fusion reaction.
If humans could capture the same energy, we would gain a virtually limitless source of clean power.
But human-made reactors are intricate and complex. A gas of ionized hydrogen is heated by microwaves and particle beams to temperatures approaching those of the sun. The hot gas is contained in a magnetic field in a donut-shaped chamber called a tokamak.
The new design, a £55-million attempt by Britain, is known as the Mega Amp Spherical Tokamak (MAST) Upgrade, which was successfully tested on 29 October after seven years of construction.
Instead of a donut shape, MAST takes the form of a cored apple. The spherical form is thought to give the ionized hydrogen plasma greater stability, but the design is not yet well understood, even though U.K. physicists built its forerunner in 1999.
The MAST team has received £220 million from the British government to build a commercial version of MAST that could be ready to generate electricity by 2040, the scientists say.
In the U.S., the Princeton Plasma Physics Laboratory tested a similar design, called the National Spherical Torus Experiment, in 2016. But a magnet failed and the machine is now being rebuilt.
TRENDPOST: Over the last 50 years, tens of billions of dollars have been invested around the world to make fusion energy work. The reactors have been as quirky as they are costly and have yet to demonstrate their practicality. While hot fusioneers seek a breakthrough, the softer side of the renewable power industry is likely to render hot fusion moot.