China passes U.S. in number of top supercomputers; ORNL’s Titan drops to 5th

The Titan supercomputer at Oak Ridge National Laboratory is pictured above. (Photo by ORNL/U.S. Department of Energy)

The Titan supercomputer at Oak Ridge National Laboratory is pictured above. (Photo by ORNL/U.S. Department of Energy)


China has passed the United States in the total number of top ranked supercomputers, and Titan at Oak Ridge National Laboratory has dropped from fourth to fifth on the TOP500 list of the world’s fastest supercomputers.

The TOP500 list is released twice a year, once in June and once in November. It is based on a benchmark test known as Linpack.

Titan at ORNL dropped from third to fourth in June, bumped from the number three spot by the upgraded Piz Daint, a Cray XC50 system installed at the Swiss National Supercomputing Centre. Titan is capable of 17.59 petaflops. A petaflop is one quadrillion calculations per second. That’s 1,000 trillion calculations per second. Piz Daint is capable of 19.59 petaflops.

That power is useful in scientific research. At ORNL, Titan is used for research in areas such as materials science, nuclear energy, combustion, and climate science. ORNL is a U.S. Department of Energy laboratory.

Titan slipped one more spot in this month’s list, from fourth to fifth. It was displaced by the upgraded Gyoukou supercomputer. That is a ZettaScaler-2.2 system capable of 19.14 petaflops and deployed at Japan’s Agency for Marine-Earth Science and Technology, the home of the Earth Simulator. [Read more…]

‘Atomic switcheroo’ explains origins of thin-film solar cell mystery

Current Maps

Cross-sectional electron beam-induced current maps show the difference in cadmium telluride solar cells before (pictured above) and after (below) cadmium chloride treatment. The increased brightness after treatment indicates higher current collection at the grain boundaries. (Submitted photo)

Treating cadmium-telluride (CdTe) solar cell materials with cadmium-chloride improves their efficiency, but researchers have not fully understood why. Now, an atomic-scale examination of the thin-film solar cells led by Oak Ridge National Laboratory has answered this decades-long debate about the materials’ photovoltaic efficiency increase after treatment.

A research team from ORNL, the University of Toledo, and the U.S. Department of Energy’s National Renewable Energy Laboratory used electron microscopy and computational simulations to explore the physical origins of the unexplained treatment process. The results are published in Physical Review Letters, or PRL.

Thin-film CdTe solar cells are considered a potential rival to silicon-based photovoltaic systems because of their theoretically low cost per power output and ease of fabrication. Their comparatively low historical efficiency in converting sunlight into energy, however, has limited the technology’s widespread use, especially for home systems. [Read more…]

Neutrons, electrons, and theory reveal secrets of natural gas reserves

Scanning Electronic Microscope Image of Unconventional Gas Reservoir

A scanning electron microscope image illustrating mineralogy and texture of an unconventional gas reservoir. Note that nanoporosity is not resolvable with this image. SANS and USANS analysis is required to quantify pore size distribution and interconnectivity. (Photo courtesy Oak Ridge National Laboratory)

Gas and oil deposits in shale have no place to hide from an Oak Ridge National Laboratory technique that provides an inside look at pores and reveals structural information potentially vital to the nation’s energy needs.

The research by scientists at the U.S. Department of Energy laboratory could clear the path to the more efficient extraction of gas and oil from shale, environmentally benign and efficient energy production from coal, and perhaps viable carbon dioxide sequestration technologies, according to Yuri Melnichenko, an instrument scientist at ORNL’s High Flux Isotope Reactor. [Read more…]