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Clocking the Movement of Electrons Inside an Atom – Down to a Millionth of a Billionth of a Second

Scientists get dramatically better resolution at X-ray free-electron lasers with a new technique.

Intense, ultrashort X-ray pulses from hard X-ray free-electron lasers (XFELs) can capture images of biological structures down to the atomic scale and shed light on the fastest processes in nature with a shutter speed of just one femtosecond, a millionth of a billionth of a second.

However, on these miniscule time scales, it is extremely difficult to synchronize the X-ray pulse that sparks a reaction in the sample with the follow-up pulse that observes the reaction. This problem, called timing jitter, is a major hurdle in performing these XFEL experiments with ever-better resolution.

New Metamaterial Structures for Studying the Oldest Light in the Universe

The cosmic microwave background, or CMB, is the electromagnetic echo of the Big Bang, radiation that has been traveling through space and time since the very first atoms were born 380000 years after our universe began. Mapping minuscule variations in the CMB tells scientists about how our universe came to be and what it’s made of.

To capture the ancient, cold light from the CMB, researchers use specialized telescopes equipped with ultrasensitive cameras for detecting millimeter-wavelength signals. The next-generation cameras will contain up to 100000 superconducting detectors. Fermilab scientist and University of Chicago Associate Professor Jeff McMahon and his team have developed a new type of metamaterials-based antireflection coating for the silicon lenses used in these cameras.

“There are at least half a dozen projects that would not be possible without these,” McMahon said.

Supercomputer-Powered Machine Learning Supports Fusion Energy Reactor Design

Energy researchers have been reaching for the stars for decades in their attempt to artificially recreate a stable fusion energy reactor. If successful, such a reactor would revolutionize the world’s energy supply overnight, providing low-radioactivity, zero-carbon, high-yield power – but to date, it has proved extraordinarily challenging to stabilize. Now, scientists are leveraging supercomputing power from two national labs to help fine-tune elements of fusion reactor designs for test runs.

In experimental fusion reactors, magnetic, donut-shaped devices called “tokamaks” are used to keep the plasma contained: in a sort of high-stakes game of Operation, if the plasma touches the sides of the reactor, the reaction falters and the reactor itself could be severely damaged. Meanwhile, a divertor funnels excess heat from the vacuum.

In France, scientists are building the world’s largest fusion reactor: a 500-megawatt experiment called ITER that is scheduled to begin trial operation in 2025. The researchers here were interested in estimating ITER’s heat-load width: that is, the area along the divertor that can withstand extraordinarily hot particles repeatedly bombarding it.

Ion-optics-based quantum microscope can image individual atoms

A team of researchers at Universität Stuttgart has developed an ion-optics-based quantum microscope that is capable of creating images of individual atoms. In their paper published in the journal Physical Review Letters, the group explains how they built their microscope and how well it worked when tested.

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