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To learn more about our early universe, scientists are trying to create a state of matter that hasnt existed since the first moments after the big bang. Physicists from Livermore and dozens of other institutions around the world are using the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory to generate this primordial matter, a quarkgluon plasma. Inside the collider, gold nuclei travel at almost the speed of light. When the nuclei collide, they generate huge amounts of energy and millions of new particles. Measurements from the Pioneering High-Energy Nuclear Interaction Experiment (PHENIX) detector, which Livermore helped to design, are analyzed to determine whether the colliding ions actually created a quarkgluon plasma. Results to date are inconclusive. One set of data based on the volume of the collision zone (or source) indicates that little or no plasma was created, while a relatively low number of high-momentum particles indicates the presence of a plasma. To supply what they hope will be more conclusive data, the Livermore team is adding another detector to PHENIX that can analyze collisions between protons and nuclei.
Forty-five years after the cessation of aboveground nuclear testing in the Marshall Islands, Livermores scientists continue to provide environmental measurement data and dose assessments to Marshallese who wish to resettle their native islands. For more than 25 years, Livermore scientists have conducted a sampling program to evaluate the various exposure pathways for radiological dose. Results indicate that ingestion is the most significant exposure pathway, mostly through uptake of cesium-137 into island-grown foods. To help reduce the dose to returning residents, Livermore developed a two-pronged remediation technique that reduces uptake of cesium-137 into locally grown foods and external radiation exposure to cesium-137. Individual radiation protection programs have been developed that use whole-body counting systems and plutonium urinalysis to assess the intake of radionuclides from residual fallout contamination. Whole-body counting facilities, operated and maintained by Marshallese technicians trained at Livermore, directly measure cesium-137 level in an individuals body. Livermore also developed a measurement technology based on accelerator mass spectrometry that is about 100 times more sensitive in detecting the amount of plutonium in human urine than other techniques.
Researchers are taking a first step toward a comprehensive, three-dimensional model of a living cell by simulating calcium ions moving within and between epithelial cells.
Lawrence Livermore National Laboratory
UCRL-52000-03-1/2 | January 23, 2003