Los Alamos National Laboratory December Tip Sheet
WE CAUGHT A MESS OF 'EM Using optical trapping techniques, Los Alamos researchers have developed a trap that holds up to six million radioactive atoms, 100 times as many as any previous effort. The Laboratory experiment uses radioactive rubidium-82, which is implanted into a foil located inside a transparent, cubicle optical trap. Heating the foil causes the rubidium to diffuse out and into the cell as free- floating atoms. Six laser beams illuminate and slow the atoms, trapping them as a glowing, millimeter-sized cloud in the center of the trap. The intensity of luorescent light emitted by the cloud gives a measure of how many atoms there are. The ability to trap large numbers of atoms allows researchers to conduct fundamental physics experiments with much greater precision than previously possible. It also holds promise for developing sophisticated analytical tools for use in a number of applications, including nonproliferation. Gary Kliewer, 505-665-2085, [email protected]
HONEY, I SHRUNK THE OIL RIG A consortium of oil and gas producing and service companies is backing Los Alamos development of scaled-down drilling equipment that will improve the oil industry's ability to detect, monitor and recover more oil from existing reservoirs. The Laboratory will assemble and test the hardware required to cut small-diameter boreholes and insert miniaturized sensors to measure pressure, temperature, sonic travel times and other clues to the underground conditions. Cuttings and fluid samples also could be recovered. Because 1-3/8 inch diameter holes will be made with very small drilling units and small crews on locations a fraction the size required for conventional drilling rigs, these microboreholes will enable the long-term use of sensors to monitor depleted reservoirs with much lower cost and lower environmental impact than standard rigs. Gary Kliewer, 505-665-2085, [email protected]
GROWING PARTS Los Alamos scientists are using a commercial process patented by DTM Corporation to fabricate three-dimensional models using laser beams and polymer powders. Los Alamos worked with DTM under a Cooperative Research and development Agreement to improve the existing DTM process for laser sintering and to extend the process to new materials. With selective laser sintering, researchers or industry personnel can use computer programs to "machine" three-dimensional models of parts. A computer program, such as a computer-aided-drafting program, defines how to direct a laser beam onto a stream of polymer powder, which fuses upon contact with the beam. In this way -- and unlike traditional machining, which removes raw material to produce a part -- selective laser sintering "grows" a part in three-dimensional space. The process allows researchers or others to produce parts with extremely complex geometries that otherwise could not be machined, cast or molded. Los Alamos originally used the process to produce concept models of nuclear weapons components from the enduring national stockpile and continues to use the process for scale models of such things as the target chamber for the National Ignition Facility. Los Alamos is working to further develop the process to produce actual parts out of plastics as well as process- coated metals. Selective laser sintering has been adapted to work with other computer programs, such as surface mapping programs or modeling codes. James Rickman, 505-665-9203, [email protected]
NEPTUNIUM CROWNED Los Alamos researchers have demonstrated a chemical reaction that offers a potential new approach for selectively removing radioactive actinide ions from process streams, waste solutions or environmental waters. The researchers showed that an organic molecule called a "crown ether" acted as a ligand, or complexing agent, to completely encapsulate a dioxo-neptunium cation (an ionized molecule formed from two oxygen atoms and one neptunium atom) in water. This had previously been seen only with dioxo- uranium cations in organic solvents. The encapsulation of a transuranic element under aqueous conditions suggests the potential use of such ligands for removing radionuclides from contaminated waters. The combined molecular compound crystallized out of the aqueous solution as large, turquoise-colored crystals. The researchers, part of Los Alamos' Seaborg Institute for Transactinium Science, used x-ray diffraction and laser spectroscopy to confirm the neptunium's complete encapsulation and are now looking at whether the process occurs with heavier actinide oxo-ions such as ones of plutonium and americium. James Rickman, 505-665-9203, [email protected]
For assistance call 505-667-7000 12/97
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