- Number 397 |
- September 16, 2013
DOE’s Fermilab has switched on its newly upgraded neutrino beam, soon to be the most intense in the world. The laboratory spent the past 15 months upgrading its accelerator complex in preparation for the NOvA experiment, which will study neutrinos using a 200-ton particle detector at Fermilab and a 14,000-ton detector in northern Minnesota.
Neutrinos are light, neutral particles that rarely interact with other matter. About a decade ago, scientists discovered that neutrinos must have mass, but they must weigh at least a million times less than electrons. The NOvA experiment aims to determine which of the three known types of neutrinos is the heaviest and which is the lightest. To do that, Fermilab will send intense neutrino beams through the earth to the huge NOvA detector in Minnesota.
Scientists at DOE's Brookhaven Lab have identified a series of clues that particular arrangements of electrical charges known as "stripes" may play a role in superconductivity—the ability of some materials to carry electric current with no energy loss. But uncovering the detailed relationship between these stripe patterns and the appearance or disappearance of superconductivity is extremely difficult, particularly because the stripes that may accompany superconductivity are very likely moving, or fluctuating.
As a step toward solving this problem, the Brookhaven team used an indirect method to detect fluctuating stripes of charge density in a material closely related to a superconductor. The research identifies a key signature to look for in superconductors as scientists seek ways to better understand and engineer these materials for future energy-saving applications.
Inside the chemical processes to synthesize simple table salt crystals, or NaCl, intense electric fields occur, according to scientists at DOE’s Pacific Northwest National Laboratory. The 5 GV/m fields, typically associated with particle accelerators, can alter the NaCl solution's electronic structure. These findings are the next step in determining the exact mechanism underlying salt's crystallization and the long-lived cobalt blue light emitted during salt formation.
“The basic point is that if luminescence occurs, something very different is actually happening than what we think is happening," said Dr. Bernhard Sellner, a PNNL postdoctoral fellow and a theoretical chemist on the study.
Could graphene – a one-layer thick sheet of carbon atoms – be the ingredient needed for super-efficient solar harvesting with metamaterials? Or for “light on wire” plasmonic data transmission? In the Aug. 9 issue of Science, Ames Laboratory physicists discussed the potential and challenges of using graphene in metamaterials and plasmonics in terahertz applications, which operate at frequencies between microwave and infrared waves.
Metamaterials are man-made structures that exhibit properties not possible in natural materials, such as refracting light “backward” or absorbing all the light that hits them. Costas Soukoulis and fellow Ames Laboratory physicists Philippe Tassin and Thomas Koschny found that graphene may be a good candidate to replace the metals currently used to build metamaterials.