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alternative_right shares a report from ScienceAlert: At the Experimental Advanced Superconducting Tokamak (EAST), physicists successfully exceeded what is known as the Greenwald limit, a practical density boundary beyond which plasmas tend to violently destabilize, often damaging reactor components. For a long time, the Greenwald limit was accepted as a given and incorporated into fusion reactor engineering. The new work shows that precise control over how the plasma is created and interacts with the reactor walls can push it beyond this limit into what physicists call a 'density-free' regime. [...] A team led by physicists Ping Zhu of Huazhong University of Science and Technology and Ning Yan of the Chinese Academy of Sciences designed an experiment to take this theory further, based on a simple premise: that the density limit is strongly influenced by the initial plasma-wall interactions as the reactor starts up. In their experiment, the researchers wanted to see if they could deliberately steer the outcome of this interaction. They carefully controlled the pressure of the fuel gas during tokamak startup and added a burst of heating called electron cyclotron resonance heating. These changes altered how the plasma interacts with the tokamak walls through a cooler plasma boundary, which dramatically reduced the degree to which wall impurities entered the plasma. Under this regime, the researchers were able to reach densities up to about 65 percent higher than the tokamak's Greenwald limit. This doesn't mean that magnetically confined plasmas can now operate with no density limits whatsoever. However, it does show that the Greenwald limit is not a fundamental barrier and that tweaking operational processes could lead to more effective fusion reactors. The findings have been published in Science Advances.

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Initial £7M estimate proves optimistic after multiple contract uplifts

The Bank of England has trebled the amount it is spending on its Oracle systems integrator amid efforts to migrate business applications to the cloud.…

As you should, when being told the only remedy is deleting everything and starting again

On Call 2025 has ended and a new year is upon us, but The Register will continue opening Friday mornings with a fresh installment of On Call – the reader-contributed column that tells your tales of tech support.…

Researchers at Stanford University have created a programmable synthetic "skin" that can independently change color and texture, "a feat previously only available within the animal kingdom," reports the Register. From the report: The technique employs electron beams to write patterns and add optical layers that create color effects. When exposed to water, the film swells to reveal texture and colors independently, depending on which side of the material is exposed, according to a paper published in the scientific journal Nature this week. In an accompanying article, University of Stuttgart's Benjamin Renz and Na Liu said the researchers' "most striking achievement was a photonic skin in which color and texture could be independently controlled, mirroring the separate regulation... in octopuses." The research team used the polymer PEDOT:PSS, which can swell in water, as the basis for their material. Its reaction to water can be controlled by irradiating it with electrons, creating textures and patterns in the film. By adding thin layers of gold, the researchers turned surface texture into tunable optical effects. A single layer could be used to scatter light, giving the shiny metal a matte, textured appearance. To control color, a polymer film was sandwiched between two layers of gold, forming an optical cavity, which selectively reflects light.

Read more of this story at Slashdot.

Nobody really needs an AI toothbrush that sends their gums to the cloud

Opinion Another Consumer Electronics Show has rolled through Las Vegas, and this year vendors scrawled “AI-enabled” on all the kit they hope will find its way into your home – while airbrushing away its immaturity and downsides.…

Outages hit Russia and Ukraine, too

The authors of a hypothetical manual containing procedures repressive governments can use to stay in power despite restive populations would surely devote its first chapter to turning off the internet, an action the government of Iran appears to have taken in the last 24 hours.…