First Tabletop X-Ray Laser {more or less} (C&EN)

[eppur_se_muova]

By Stu Borman

The world’s first tabletop X-ray laser doesn’t require a trip to a synchrotron facility and produces pulses fast enough to capture blindingly fast chemical processes.

If commercialized as planned, the system could make it possible to carry out new types of spectroscopic and materials studies at relatively affordable costs. Potential applications include monitoring and analyzing short-timescale chemical processes such as charge, spin, light, and energy interactions in advanced materials.

The tabletop coherent X-ray beam is generated through a nonlinear optical technique called high harmonic generation. The beam was developed by Tenio Popmintchev, Margaret Murnane, Henry Kapteyn, and coworkers at the University of Colorado, Boulder, as well as collaborators at Vienna Institute of Technology, Cornell University, and the University of Salamanca, in Spain (Science, DOI: 10.1126/science.1218497).

“The work’s impact is significant for chemistry,” says Richard Haight, an X-ray applications expert at IBM’s T. J. Watson Research Center, in Yorktown Heights, N.Y. For example, it could make it possible to characterize materials with exceptional time precision by using core-level photoelectron spectroscopy to study atomic oxidation states, he says. And with appropriate X-ray optics, the laser could be focused “to time-resolve chemistry at nanoscale dimensions, opening a new and exciting field of attochemistry,” he adds.

In high harmonic generation, an infrared laser is focused into a waveguide cell filled with helium gas under high pressure. The laser iteratively ionizes helium atoms and drives the released electrons back to the helium ions. The process causes each ion to “upconvert” sets of 5,000 low-energy IR photons into individual high-energy soft X-ray photons. A process called phase matching, achieved by tuning the gas pressure, ensures that the resulting X-ray waves interfere constructively with one another, creating a coherent beam. Strictly speaking, the beam is laserlike instead of a laser per se because the X-ray beam is not produced by direct lasing, which would require a prohibitive amount of power.
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more: http://cen.acs.org/articles/90/i24/First-Tabletop-X-Ray-Laser.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+cen_latestnews+%28Chemical+%26+Engineering+News%3A+Latest+News%29

[phantom power]

1. That is cool. A bit like a step-up xformer for photons.

[caraher]

2. They finally got there!

I met Margaret & Henry back in the mid-90s when I was in grad school and they came to Michigan (before moving on to Colorado). This has been their goal for many, many years. It's been a long road to x-rays and I look forward to seeing KMLabs offering a commercial version a few years down the road!