Tag Archives: diffraction

Bottling Up Sound Waves

Acoustic Bottle Beams from Berkeley Lab Hold Promise for Imaging, Cloaking, Levitation and Other Apps

There’s a new wave of sound on the horizon carrying with it a broad scope of tantalizing potential applications, including advanced ultrasonic imaging and therapy, and acoustic cloaking, levitation and particle manipulation. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a technique for generating acoustic bottles in open air that can bend the paths of sound waves along prescribed convex trajectories. (more…)

Read More

Physicists Demonstrate the Acceleration of Electrons by a Laser in a Vacuum

Accelerating a free electron with a laser has been a longtime goal of solid-state physicists.

David Cline, a distinguished professor in the UCLA Department of Physics and Astronomy, and Xiaoping Ding, an assistant researcher at UCLA, have conducted research at Brookhaven National Laboratory in New York and have established that an electron beam can be accelerated by a laser in free space.

This has never been done before at high energies and represents a significant breakthrough, Cline said, adding that it also may have implications for fusion as a new energy source. (more…)

Read More

Breakthrough in Nanocrystals Growth

Nanoparticles. Image credit: Wenge Yang

Argonne, ILL — For the first time scientists have been able to watch nanoparticles grow from the earliest stages of their formation. Nanoparticles are the foundation of nanotechnology and their performance depends on their structure, composition, and size. Researchers will now be able to develop ways to control conditions under which they are grown. The breakthrough will affect a wide range of applications including solar-cell technology and chemical and biological sensors. The research is published in NANOLetters.

As coauthor Wenge Yang of the Carnegie Institution’s Geophysical Laboratory explained: “It’s been very difficult to watch these tiny particles be born and grow in the past because traditional techniques require that the sample be in a vacuum and many nanoparticles are grown in a metal-conducting liquid. So we have not been able to see how different conditions affect the particles, much less understand how we can tweak the conditions to get a desired effect.” (more…)

Read More