Helium atoms sent by nozzle may light way for new imaging approach

Jul 26, 2006

A newly devised nozzle fitted with a pinhole-sized capillary has allowed researchers to distribute helium atoms with X-ray-like waves on randomly shaped surfaces. The technique could power the development of a new microscope for nanotechnology, allowing for a non-invasive, high-resolution approach to studying both organic and inorganic materials.

All that is needed is a camera-like detector, which is now being pursued, to quickly capture images that offer nanometer resolution, said principal investigator Stephen Kevan, a physics professor at the University of Oregon. If successful, he said, the approach would build on advances already achieved with emerging X-ray-diffraction techniques.

Reporting in the July 7 issue of Physical Review Letters, Kevan's four-member team described how they sent continuous beams of helium atoms and hydrogen molecules precisely onto material with irregular surfaces and measured the speckle diffraction pattern as the wave-like atoms scattered from the surface.

The research, funded by the National Science Foundation and U.S. Department of Education, was the first to capture speckle diffraction patterns using atomic de Broglie waves. The Nobel Prize in physics went to France's Louis de Broglie in 1929 for his work on the properties of matter waves.

"The approach of using the wave nature of atoms goes back 100 years to the founding of quantum mechanics," Kevan said. "Our goal is to make atomic de Broglie waves that have very smooth wave fronts, as in the case in laser light. Usually atom sources do not provide wave fronts that are aligned coherently, or nice and orderly."

The nozzle used in the experiments is similar to one on a garden hose. However, it utilizes a micron-sized glass capillary, borrowed from patch-clamp technology used in neuroscience. The capillary, smaller than a human hair, provides very small but bright-source atoms that can then be scattered from a surface. This distribution of scattered atoms is measured with high resolution using a field ionization detector.

The helium atoms advance with de Broglie wavelengths similar to X-rays, but are neutral and non-damaging to the surface involved. Kevan's team was able to measure single-slit diffraction patterns as well as speckle patterns made on an irregularly shaped object.

Getting a timely image remains the big obstacle, Kevan said. Images of diffraction patterns produced pixel-by-pixel in the study required hours to accumulate and suffer from thermal stability limitations of the equipment. "We'd like to measure the speckle diffraction patterns in seconds, not a day," he said.

"Given its simplicity, relative low cost, continuous availability, and the unit probability for helium scattering from surfaces, our source will be very competitive in some applications," Kevan and colleagues wrote.

"This atom optical experiment would benefit from developing an 'atom camera,' that would measure the entire speckle pattern in one exposure," they wrote.

Source: University of Oregon

Explore further: Team invents microscopic sonic screwdriver

Related Stories

Layered compounds for li-ion batteries

Apr 28, 2015

Researchers from the Institute of Science, University Teknologi MARA Selangor conducted a study into the possibility of using new and cost effective compounds in Li ION battery application.

Weighing and imaging molecules one at a time

Apr 27, 2015

Building on their creation of the first-ever mechanical device that can measure the mass of individual molecules, one at a time, a team of Caltech scientists and their colleagues have created nanodevices ...

Humble neutron is valuable tool in geology

Mar 16, 2015

With the ability to analyse the properties of the Earth's internal components to the atomic scale in conditions only found kilometres below our feet, recent studies have allowed geoscientists to study our ...

Recommended for you

Researchers prove magnetism can control heat, sound

7 hours ago

Phonons—the elemental particles that transmit both heat and sound—have magnetic properties, according to a landmark study supported by Ohio Supercomputer Center (OSC) services and recently published by ...

How researchers listen for gravitational waves

16 hours ago

A century ago, Albert Einstein postulated the existence of gravitational waves in his General Theory of Relativity. But until now, these distortions of space-time have remained stubbornly hidden from direct ...

What's fair?: New theory on income inequality

May 27, 2015

The increasing inequality in income and wealth in recent years, together with excessive pay packages of CEOs in the U.S. and abroad, is of growing concern, especially to policy makers. Income inequality was ...

Scientists one step closer to mimicking gamma-ray bursts

May 27, 2015

Using ever more energetic lasers, Lawrence Livermore researchers have produced a record high number of electron-positron pairs, opening exciting opportunities to study extreme astrophysical processes, such ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.