Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New technique by CU-Boulder researchers opens door to tabletop X-ray laser

27.02.2007
A team of researchers at the University of Colorado at Boulder has developed a new technique to generate laser-like X-ray beams, removing a major obstacle in the decades-long quest to build a tabletop X-ray laser that could be used for biological and medical imaging.

For nearly half a century, scientists have been trying to figure out how to build a cost-effective and reasonably sized X-ray laser to provide super-high imaging resolution, according to CU-Boulder physics professors Henry Kapteyn and Margaret Murnane, who led the team at JILA, a joint institute of CU-Boulder and the National Institute of Standards and Technology. Most of today's X-ray lasers require so much power that they rely on fusion laser facilities the size of football stadiums, making their use impractical.

"We've come up with a good end run around the requirement for a monstrous power source," Kapteyn said.

A paper on the subject by Murnane and Kapteyn, CU-Boulder graduate students Xiaoshi Zhang, Amy Lytle, Tenio Popmintchev, Xibin Zhou and Senior Research Associate Oren Cohen of JILA was published in the online version of the journal Nature Physics on Feb. 25.

If they can extend the new technique all the way into the hard X-ray region of the electromagnetic spectrum, which they think is just a matter of time because there are no physical principles blocking the way, the ramifications would be felt in numerous fields.

"If we can do this, it might make it possible to improve X-ray imaging resolution by a thousand times, with impacts in medicine, biology and nanotechnology," Murnane said. "For example, the X-rays we get in the hospital are limited by spatial resolution. They can't detect really small cancers because the X-ray source in your doctor's office is like a light bulb, not like a laser. If you had a bright, laser-like X-ray beam, you could image with far higher resolution."

To generate laser-like X-ray beams, the team used a powerful laser to pluck an electron from an atom of argon, a highly stable chemical element, and then slam it back into the same atom. The boomerang action generates a weak, but directed beam of X-rays.

The obstacle they needed to hurdle was combining different X-ray waves emitted from a large number of atoms to generate an X-ray beam bright enough to be useful, according to Kapteyn. In other words, they needed to generate big enough waves flowing together to make a strong X-ray.

The biggest problem was the waves of X-rays do not all come out "marching in step" because visible laser light and X-ray beams travel at different speeds in the argon gas, Murnane said. This meant that while some X-ray waves combined with other waves from similar regions to become stronger, waves from different regions would cancel each other out, making the X-ray output weaker.

To correct this, the researchers sent some weak pulses of visible laser light into the gas in the opposite direction of the laser beam generating the X-rays. The weak laser beam manipulates the electrons plucked from the argon atoms, whose emissions are out of sync with the main beam, and then slams them back into the atoms to generate X-rays at just the right time, intensifying the strength of the beam by over a hundred times.

"Think of a kid on a swing," Kapteyn said. "If you keep pushing at the right time the swing goes higher and higher, but if you don't push it at the right time, you'll eventually stop it.

"What we found is essentially another beam of light to control exactly when the swing is getting pushed. By putting the light in the right place, we don't allow the swing to be pushed at the wrong time."

Henry Kapteyn | EurekAlert!
Further information:
http://www.colorado.edu

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>