From DOE’s Lawrence Livermore National Laboratory (US) : “A bigger nursery for the solar system’s first formed solids”

From DOE’s Lawrence Livermore National Laboratory (US)

Anne M Stark

A piece of carbonaceous chondrite that contains a large calcium-aluminum-rich inclusion similar to those used in this study. Photo by: Quinn Shollenberger/LLNL.

By studying isotopic variations of the elements vanadium (V) and strontium (Sr), an international team of researchers including scientists from Lawrence Livermore National Laboratory (LLNL) found that those variations are not caused by irradiation from the sun but are produced by condensation and evaporation reactions in the early solar system. The research appears in the Sept. 29 edition of Science Advances.

“It turns out that some of the short-lived radioactive isotopes researchers previously thought were products of irradiation from the early active sun are instead most likely inherited from our parent molecular cloud, which, in turn, tells us a significant amount about the cosmic neighborhood we grew up in,” said LLNL cosmochemist Greg Brennecka, a co-author of the paper.

Calcium-Aluminum-rich inclusions (CAIs) in meteorites are the oldest dated solids that formed within the solar system. They carry crucial information regarding the environmental conditions of the earliest stages of the protoplanetary disk before any of the planets formed. This research also suggests that the oldest solids in our solar system could have formed further away from the sun than previously thought, with far-reaching implications regarding the dynamical structure of the nascent solar system.

“Our findings indicate that CAI formation during molecular cloud infall and disk build-up likely occurred at greater distances from the sun that we thought before, potentially up to planet-forming regions of the solar system,” said LLNL postdoc Quinn Shollenberger, a co-author of the paper.

Astronomical observations of young stellar objects indicate that their surrounding accretionary disks are directly exposed to levels of X-ray and high-energy particle emissions that are orders of magnitude higher than observed for most main sequence stars. However, the duration and characteristics (gradual or impulsive flares) of these early stages of high stellar activity remain poorly understood.

Anomalous abundances of short-lived radionuclides in CAIs of carbonaceous chondrite meteorites have been suggested to be fossil records of dust irradiation by solar cosmic rays at the inner edge of the protoplanetary disk. But the new research topples that theory. “Knowing where CAIs formed is crucial for us to understand the distribution and evolution of planet-forming dust in the nascent solar system,” said David Bekaert, first author of the study.

These refractory inclusions are present in objects that formed in various parts of the solar system, and have even been found in comets that formed very far away from the sun. If CAIs originally formed very close to the sun, it tells scientists there was very vigorous and fast mixing throughout the protoplanetary disk. However, if these objects only formed in planet-forming regions further from the sun, as suggested by the recent paper, then far less radial mixing is required to have taken place.

“Basically, it gives us a feel for how high the blender was turned on. The speed of that blender is important for understanding how material moved around the early solar system, and why the solar system is arranged the way it is (gas giants outside, terrestrial bodies inside),” Brennecka said. “This study greatly relaxes the area in which the first solids of the solar system could have formed.”

Contributors to this work include LLNL scientist Ben Jacobsen, as well as researchers from The Woods Hole Oceanographic Institution (US), The University of Münster [Westfälische Wilhelms-Universität Münster] (DE), The University of California-Los Angeles (US), Goethe University [Goethe-Universität] Frankfurt(DE), Durham University (UK) and The Smithsonian National Museum of Natural History (US). The research was funded by LLNL’s Laboratory Directed Research and Development program.

See the full article here .


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Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration

DOE’s Lawrence Livermore National Laboratory (LLNL) (US) is an American federal research facility in Livermore, California, United States, founded by the University of California-Berkeley (US) in 1952. A Federally Funded Research and Development Center (FFRDC), it is primarily funded by the U.S. Department of Energy (DOE) and managed and operated by Lawrence Livermore National Security, LLC (LLNS), a partnership of the University of California, Bechtel, BWX Technologies, AECOM, and Battelle Memorial Institute in affiliation with the Texas A&M University System (US). In 2012, the laboratory had the synthetic chemical element livermorium named after it.

LLNL is self-described as “a premier research and development institution for science and technology applied to national security.” Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.

The Laboratory is located on a one-square-mile (2.6 km^2) site at the eastern edge of Livermore. It also operates a 7,000 acres (28 km2) remote experimental test site, called Site 300, situated about 15 miles (24 km) southeast of the main lab site. LLNL has an annual budget of about $1.5 billion and a staff of roughly 5,800 employees.

LLNL was established in 1952 as the University of California Radiation Laboratory at Livermore, an offshoot of the existing UC Radiation Laboratory at Berkeley. It was intended to spur innovation and provide competition to the nuclear weapon design laboratory at Los Alamos in New Mexico, home of the Manhattan Project that developed the first atomic weapons. Edward Teller and Ernest Lawrence, director of the Radiation Laboratory at Berkeley, are regarded as the co-founders of the Livermore facility.

The new laboratory was sited at a former naval air station of World War II. It was already home to several UC Radiation Laboratory projects that were too large for its location in the Berkeley Hills above the UC campus, including one of the first experiments in the magnetic approach to confined thermonuclear reactions (i.e. fusion). About half an hour southeast of Berkeley, the Livermore site provided much greater security for classified projects than an urban university campus.

Lawrence tapped 32-year-old Herbert York, a former graduate student of his, to run Livermore. Under York, the Lab had four main programs: Project Sherwood (the magnetic-fusion program), Project Whitney (the weapons-design program), diagnostic weapon experiments (both for the DOE’s Los Alamos National Laboratory(US) and Livermore laboratories), and a basic physics program. York and the new lab embraced the Lawrence “big science” approach, tackling challenging projects with physicists, chemists, engineers, and computational scientists working together in multidisciplinary teams. Lawrence died in August 1958 and shortly after, the university’s board of regents named both laboratories for him, as the Lawrence Radiation Laboratory.

Historically, the DOE’s Lawrence Berkeley National Laboratory (US) and Livermore laboratories have had very close relationships on research projects, business operations, and staff. The Livermore Lab was established initially as a branch of the Berkeley laboratory. The Livermore lab was not officially severed administratively from the Berkeley lab until 1971. To this day, in official planning documents and records, Lawrence Berkeley National Laboratory is designated as Site 100, Lawrence Livermore National Lab as Site 200, and LLNL’s remote test location as Site 300.

The laboratory was renamed Lawrence Livermore Laboratory (LLL) in 1971. On October 1, 2007 LLNS assumed management of LLNL from the University of California, which had exclusively managed and operated the Laboratory since its inception 55 years before. The laboratory was honored in 2012 by having the synthetic chemical element livermorium named after it. The LLNS takeover of the laboratory has been controversial. In May 2013, an Alameda County jury awarded over $2.7 million to five former laboratory employees who were among 430 employees LLNS laid off during 2008.The jury found that LLNS breached a contractual obligation to terminate the employees only for “reasonable cause.” The five plaintiffs also have pending age discrimination claims against LLNS, which will be heard by a different jury in a separate trial.[6] There are 125 co-plaintiffs awaiting trial on similar claims against LLNS. The May 2008 layoff was the first layoff at the laboratory in nearly 40 years.

On March 14, 2011, the City of Livermore officially expanded the city’s boundaries to annex LLNL and move it within the city limits. The unanimous vote by the Livermore city council expanded Livermore’s southeastern boundaries to cover 15 land parcels covering 1,057 acres (4.28 km^2) that comprise the LLNL site. The site was formerly an unincorporated area of Alameda County. The LLNL campus continues to be owned by the federal government.

NIF National Ignition Facility located at the DOE’s Lawrence Livermore National Laboratory in Livermore, California.