Tag Archives: NIST

X-rays from Copper Source Set New Gold Standard for Measuring Industrial Materials

By Alison Gillespie – Researchers at the National Institute of Standards and Technology (NIST) have produced and precisely measured a spectrum of X-rays using a new, state-of-the-art machine. The instrument they used to measure the X-rays took 20 years to develop, and will help scientists working at the agency make some of the world’s most accurate measurements of materials for use in everything from bridges to pharmaceuticals.

The process of building the instrument for making the new measurements was painstaking. “This new specialized precision instrument required both a tremendous amount of mechanical innovation and theoretical modeling,” said James Cline, project leader of the NIST team that built the machine.

“That we were able to dedicate so many years and such high-level scientific expertise to this project is reflective of NIST’s role in the world of science.” more> https://goo.gl/e0zrET

Turning Back Time: Watching Rust Transform into Iron

By W. Zhu, J.P. Winterstein, W.D. Yang, L. Yuan, R. Sharma and G. Zhou – Using a state-of-the-art microscopy technique, experimenters at the National Institute of Standards and Technology (NIST) and their colleagues have witnessed a slow-motion, atomic-scale transformation of rust—iron oxide—back to pure iron metal, in all of its chemical steps.

In a new effort to study the microscopic details of metal oxide reduction, researchers used a specially adapted transmission electron microscope (TEM) at NIST’s NanoLab facility to document the step-by-step transformation of nanocrystals of the iron oxide hematite (Fe2O3) to the iron oxide magnetite (Fe3O4), and finally to iron metal.

By lowering the temperature of the reaction and decreasing the pressure of the hydrogen gas that acted as the reducing agent, the scientists slowed down the reduction process so that it could be captured with an environmental TEM—a specially configured TEM that can study both solids and gas. The instrument enables researchers to perform atomic-resolution imaging of a sample under real-life conditions—in this case the gaseous environment necessary for iron oxides to undergo reduction–rather than under the vacuum needed in ordinary TEMs. more> https://goo.gl/8lJIAH

Team develops “spinning trap” to measure electron roundness

R&D – Decades ago, physicists believed the electron was perfectly round. In the 1980s, the idea of a slight asymmetry became acceptable, but any eEDM (electron’s electric dipole moment) was thought to be too tiny to see. Some current theories predict that the eEDM might be only a bit smaller than the latest measurements indicate and might arise from exotic, as-yet-unknown particles.

Scientists are now trying to push the limits of eEDM measurements to either validate or disapprove some of the competing theories. The current experimental upper limit is much, much larger than the eEDM predicted by the Standard Model of physics. But extensions to this model such as supersymmetry predict a value close to the experimental limits. By making more precise measurements, scientists hope to test these new theories. more> http://tinyurl.com/njvh9gp