One of the most critical issues the United States faces today is preventing terrorists from smuggling nuclear weapons into its ports. To this end, the U.S. Security and Accountability for Every Port Act mandates that all overseas cargo containers be scanned for possible nuclear materials or ... more
Elemental and magnetic imaging using X-rays and a microscope
A team of researchers has developed a new microscope that can image the elemental and magnetic properties of a wide range of energy-important materials that are used in devices such as solar cells and solid-state lighting.
The imager is based on a technique known as X-ray excited luminescence microscopy (XELM). It was created by hitching a standard optical microscope to a synchrotron X-ray source. Synchrotrons produce X-rays and other forms of electromagnetic radiation by sending electrons on a curved path at nearly the speed of light.
When the X-rays strike the material being imaged, some of them are absorbed, which causes the sample to luminesce. The microscope portion of the imager is able to detect differences in this luminescence, which is directly related to both the elements in the sample and their magnetic properties. This technique combines the spatial resolution of optical microscopy with the element and magnetic specificity and precision of synchrotron radiation.
It is able to spatially resolve features as small as one micron. However, this value was degraded in practice due to vibrations or subtle shifting of the systems used to direct the X-ray beam, though future refinements should alleviate any stability issues.
XELM has some advantages over other techniques in that it is especially useful at low temperatures and can image in the presence of electric and magnetic fields. The results were accepted for publication in the American Institute of Physics' journal Review of Scientific Instruments.
R.A. Rosenberg et al.; Elemental and magnetic sensitive imaging using x-ray excited luminescence microscopy; Review of Scientific Instruments
Researchers at the Paul Scherrer Institute's Swiss Light Source in Villigen, Switzerland, have developed a new design for X-ray spectrometers that eschews a commonly utilized component to lowers overall production costs and increase the efficiency of x-ray flux, which may lead to faster acq ... more
A team of American and Chinese researchers has developed a new tool that could aid in the quest for better batteries and fuel cells. Although battery technology has come a long way since Alessandro Volta first stacked metal discs in a "voltaic pile" to generate electricity, major improvemen ... more
Summer blockbuster season is upon us, which means plenty of fast-paced films with lots of action. However, these aren't new releases from Hollywood studios; they're one type of new "movies" of atomic-level explosions that can give scientists new information about how X-rays interact with mo ... more
Fat free ice cream, for all its healthy merits, melts the wrong way. Two seconds on the tongue and it's a slush of milk, flavoring and water instead of the rich glob of slowly melting cream we grew to love as kids. When it comes to taste memories, fats are forever. Now X-ray science is cont ... more
Cast iron can be modified through the manufacturing process to optimize its mechanical and physical properties, such as strength and durability. But the manufacturing process is as much art as science, producing good results yet not capturing cast iron's full potential. Controversy still ex ... more