LAB REPORT
Science and Technology Making Headlines
April 21, 2017
Opening the historic vault
Lawrence Livermore National Laboratory (LLNL) is restoring and preserving the most complete collection of films from America’s role in the era of above-ground nuclear testing.
Until the Partial Nuclear Test Ban Treaty finally ended above-ground nuclear testing in 1963, the federal government routinely satisfied the curiosity of military planners with tests above ground.
For the last five years, LLNL nuclear physicist Greg Spriggs has supervised a project to restore and declassify all the films from the 210 above-ground nuclear tests the U.S. conducted from 1945 until they were banned in 1963. He found that some films were in terrible shape, including a few from the earliest tests.
The biggest and most energetic ever
The world's largest laser is in Livermore at the National Ignition Facility and can reach temperatures six times hotter than the sun.
“Anytime we do an experiment here we like to say we are the hottest place in the solar system,” said Tammy Ma, a fusion physicist at LLNL.
The National Ignition Facility or "NIF" is located at LLNL and has two main jobs. Its first job is to keep existing nuclear bombs safe.
“We are not using the NIF to make new nuclear bombs. We are just using it to maintain the nation's deterrent,” Ma said.
Western U.S. snowpack level in hot water
An international team of scientists, including one from LLNL, has found that up to 20 percent loss in the annual maximum amount of water contained in the Western United States' mountain snowpack in the last three decades is due to human influence.
Peak runoff in streams and rivers of the Western U.S. is strongly influenced by melting of accumulated mountain snowpack. A significant decline in this resource has a direct connection to streamflow, with substantial economic and societal impacts.
The team showed that observed snowpack loss between the 1980s and 2000s is consistent with results from climate simulations with combined changes in natural factors (such as solar irradiance and volcanic aerosols) and human influences (such as greenhouse gases, aerosols, ozone and land use). The observed snowpack loss was inconsistent with simulations that considered natural influences only.
Based on the current state of the snowpack, the researchers estimate a further loss of up to 60 percent within the next 30 years. The research appears in the April 18 edition of the journal, Nature Communications.
U.S. comes clean
Americans increased their use of clean energy sources such as solar and wind, according to the 2016 energy flow chart.
Every year, LLNL produces a new energy flow chart, that resembles a spaghetti diagram, showing the sources of U.S. energy, what it’s used for and how much of it is wasted.
LLNL measures U.S. energy consumption in “quads,” which is a British thermal unit BTU, a standard unit of energy — the heat required to raise the temperature of a pound of water by 1 degree Fahrenheit. If you prefer the metric system, a BTU is about 1055 joules of energy.
A “quad” is one quadrillion (a thousand trillion) BTUs and one is equivalent to 293,071,000,000 kilowatt-hours (kWh). In 2016, the U.S. consumed 97.3 quads in 2016, an amount that has stayed roughly steady (within a quad or so) since 2000.
Look to the stars
A new series of National Ignition Facility (NIF) discovery science (DS) experiments are tackling the task of how heavy elements are formed in the interior of stars. By fusing elements such as tritium (a form of hydrogen) and helium in the NIF target chamber, a multi-institutional team of researchers hopes to gain new insights into the processes that kick-started and have sustained the universe.
The first three experiments in the campaign focused on the “proton-proton 1” chain of nuclear reactions, at the beginning of the stellar nucleosynthesis cycle. Nuclear fusion converts hydrogen into helium, and a small amount of matter is turned into energy in the process.
“This set of shots to study reactions relevant to stellar nucleosynthesis is an important step forward for the Discovery Science Program,” said Bruce Remington, the NIF DS program leader. “We have now broadened the science regimes accessible to NIF to include stellar nuclear physics.”