Tag Archives: high density

Study shows how planetary building blocks evolved from porous to hard objects

Thinking small has enabled an international team of scientists to gain new insight into the evolution of planetary building blocks in the early solar system.

The researchers compared the results of small-scale numerical simulations of colliding rock and dust particles to the composition of meteorites. They found that collisions helped transform initially porous materials into the more highly solidified asteroids and meteorites observed today. The team of seven scientists published their evidence last month in Nature Communications. (more…)

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Measuring Table-Top Accelerators’ State-of-the-Art Beams

Studies by Berkeley Lab scientists of electron beam quality in laser plasma accelerators include novel tests for slice-energy spread

Part Two: Slicing through the electron beam

Wim Leemans of Berkeley Lab’s Accelerator and Fusion Research Division heads LOASIS, the Laser and Optical Accelerator Systems Integrated Studies, an oasis indeed for students pursuing graduate studies in laser plasma acceleration (LPA). Among the most promising applications of future table-top accelerators are new kinds of light sources, in which their electron beams power free electron lasers.

“If our LPA electron bunches had good enough quality for free electron lasers – and were really only femtoseconds long – we should see a particular kind of radiation called coherent optical transition radiation, or COTR,” Leemans says. “So I assigned my doctoral student Chen Lin, a graduate of Peking University and now a postdoc there, to find it.” (more…)

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UCLA Astronomers Discover Star Racing Around Black Hole at Center of Our Galaxy

Discovery crucial to revealing fabric of space and time around black hole

UCLA astronomers report the discovery of a remarkable star that orbits the enormous black hole at the center of our Milky Way galaxy in a blistering 11-and-a-half years — the shortest known orbit of any star near this black hole. (more…)

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