- Number 369 |
- August 13, 2012
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Looking for dark matter a mile underground
For the past two years, a small bubble chamber has been on the lookout for dark-matter particles a mile underground at SNOLAB in Sudbury, Ontario. Now that experiment is about to get company – its big brother is moving in. The new particle detector, developed at the Department of Energy’s Fermi National Accelerator Laboratory, will be much more sensitive to dark-matter particles than its predecessor.
The two bubble chambers, with volumes of 2 and 30 liters respectively, are part of an experiment known as the Chicago Observatory for Underground Particle Physics. Initiated by physicist Juan Collar at the University of Chicago, COUPP initially took data in a hall 350 feet underground at Fermilab to look for dark matter. When scientists improved the sensitivity of their particle detectors, particles stemming from cosmic-ray showers created too much noise and the COUPP collaboration decided to move to the deeper SNOLAB location, which provides more shielding against cosmic rays. -
Mars rover uses nuclear power system assembled, tested in Idaho
NASA’s Mars Science Laboratory rover named Curiosity landed on the surface of Mars earlier this month and began a two-year mission exploring the planet’s Gale Crater area for signs of past and present inhabitability.
While on Mars, Curiosity will carry the most advanced payload of scientific gear ever used on the red planet. Those instruments will be powered by heat from a nuclear power system assembled and extensively tested at DOE’s Idaho National Laboratory.
The power system, produced by INL along with the Oak Ridge and Los Alamos national laboratories, provides about 110 watts of electricity and can run continuously for many years. -
Unearthing the plant-microbe quid pro quo
It takes a village of microbes to raise a plant. The microbial community in and surrounding plant roots fights pests and manages carbon and other soil nutrients, ultimately contributing to plant health and growth. What’s more, they aid plants in sequestering pollutants. Despite this, much about this process remains unknown.
Lead researchers from DOE’s Joint Genome Institute (DOE JGI) and the University of North Carolina, Chapel Hill, dug to the root of plant-microbe interaction in a new study featured on the cover of the August 2 issue of the journal Nature. The paper identifies key microbial players surrounding and in the roots of the Arabidopsis thaliana, a plant often used in experiments due to its rapid life cycle, and the first plant to have its genome sequenced. The study identified more than 750 operational taxonomic units (genetically distinct groups of microbes, similar to species) in soil and plant samples. Scientists are then able to extrapolate the metabolic functions of these groups of microbes. -
Unprecedented subatomic details of exotic ferroelectric nanomaterials
As scientists learn to manipulate little-understood nanoscale materials, they are laying the foundation for a future of more compact, efficient, and innovative devices. Adding to the toolbox to advance that goal, scientists at DOE’s Brookhaven and Lawrence Berkeley labs and collaborating institutions have developed a new technique that allows them to image individual atoms and associated electric fields in exotic ferroelectric materials. The technique reveals unprecedented details about the atomic structure and behavior of these materials, which are uniquely equipped to store digital information and could usher in a new generation of advanced electronics.
The technique, called electron holography, captures images of the electric fields created by the materials’ atomic displacement with picometer precision. By applying different levels of electricity and adjusting the temperature of the samples, researchers demonstrated a method for identifying and describing the behavior and stability of ferroelectrics at the smallest-ever scale. -
Thermal scout finds trouble at solar plants
At today’s mammoth Concentrated Solar Power plants, operators play the game of Find the Bad Receiver Bulbs.
At a 20-megawatt concentrating solar power (CSP) plant, some 10,000 mirrors reflect sunlight onto 10,000 receiver tubes, each of which must operate efficiently to get the maximum impact from the sun.
Yet, operators don’t have a good sense for which among the 10,000 tubes may have an air leak, or a hydrogen leak, or have been shattered by a flung rock. The best they can do is look at the entire output and roughly guess that if the plant seems to be operating, say, 4% under capacity, it may have about 400 bad tubes.