Tag Archives: light source

A Dual Look at Photosystem II Using the World’s Most Powerful X-Ray Laser

Berkeley Lab and SLAC Researchers Demonstrate Room Temperature Simultaneous Diffraction/Spectroscopy of Metalloenzymes

From providing living cells with energy, to nitrogen fixation, to the splitting of water molecules, the catalytic activities of metalloenzymes – proteins that contain a metal ion – are vital to life on Earth. A better understanding of the chemistry behind these catalytic activities could pave the way for exciting new technologies, most prominently artificial photosynthesis systems that would provide  clean, green and renewable energy. Now, researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the SLAC National Accelerator Laboratory have taken a major step towards achieving this goal.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the world’s most powerful X-ray laser, the researchers were able to simultaneously image at room temperature the atomic and electronic structures of photosystem II, a metalloenzyme critical to photosynthesis. (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 Engineers Shed New Light on 3-D Motion of Human Sperm Cells

Using new lensless imaging platform, team observes rare helical movements

A team of researchers from the UCLA Henry Samueli School of Engineering and Applied Science has, for the first time, directly recorded the three-dimensional helical swimming patterns of human sperm cells.

The team, led by Aydogan Ozcan, associate professor of electrical engineering and bioengineering, developed a novel lensless computational imaging platform that accurately tracked more than 24,000 individual sperm cells in a large volume. This involved observing the individual rotations of each sperm cell, including helical movement patterns, rotation speed, and linear and curved distances traveled. (more…)

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With Random Lasers, Yale Researchers Fight Random Noise, Improve Imaging

Using “random lasers” as a source of illumination in medical imaging equipment could improve both processing time and the clarity of the final images, according to new research by Yale University scientists.

Imaging systems currently rely on a variety of light sources — specialty light bulbs, light-emitting diodes (LEDs), and traditional lasers. But systems using traditional lasers, the brightest of these light sources, often yield undesirable visual byproducts that mar the final picture. One common byproduct, speckle, looks something like a snowfall pattern. (more…)

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