Scientists Film Photons With Electrons

[Ichingcarpenter]

4D electron microscopy makes it possible to image photons of nanoscale structures and visualize their architecture




Photons imaged in nanoscale structures (carbon nanotubes) using pulsed electrons at very high speed. Shown are the evanescent fields for two time frames and for two polarizations.




Techniques recently invented by researchers at the California Institute of Technology (Caltech)—which allow the real-time, real-space visualization of fleeting changes in the structure of nanoscale matter—have been used to image the evanescent electrical fields produced by the interaction of electrons and photons, and to track changes in atomic-scale structures.

Four-dimensional (4D) microscopy—the methodology upon which the new techniques were based—was developed at Caltech's Physical Biology Center for Ultrafast Science and Technology. The center is directed by Ahmed Zewail, the Linus Pauling Professor of Chemistry and professor of physics at Caltech, and winner of the 1999 Nobel Prize in Chemistry.

Zewail was awarded the Nobel Prize for pioneering the science of femtochemistry, the use of ultrashort laser flashes to observe fundamental chemical reactions occurring at the timescale of the femtosecond (one-millionth of a billionth of a second). The work "captured atoms and molecules in motion," Zewail says, but while snapshots of such molecules provide the "time dimension" of chemical reactions, they don't give the dimensions of space of those reactions—that is, their structure or architecture.

The new technique devised by Zewail and Yurtsever addresses the blurring problem by using electron pulses instead of a steady electron beam. The sample under study—in the case of the Science paper, a wafer of crystalline silicon—is first heated by being struck with a short pulse of laser light. The sample is then hit with a femtosecond pulse of electrons, which bounce off the atoms, producing a diffraction pattern on a detector.

http://www.redorbit.com/news/technology/1800543/scientists_film_photons_with_electrons/index.html

[MrScorpio]

1. Now that we've gotten that out of the way, where the Hell is my flying car?

Jeez, it's waaay deep in the 21 century already.

[puebloknot]

2. Your flying car is entangled in some cosmic hedges. You'll just have to be patient! nt