Lawrence Livermore National Laboratory scientists have for the first time recreated conditions similar to that of giant planets using the world’s largest and highest-energy laser.
Researchers, including UC Berkeley professor of earth and planetary science Raymond Jeanloz, published their findings last week in the journal Nature. Scientists used diamond samples to simulate the way carbon reacts at extremely high pressures, similar to those in the interiors of large planets such as Jupiter and Saturn. They simulated the interior pressures of such planets with ultraviolet laser beams. The laser they used, called the National Ignition Facility, spans three American football fields and is 10 stories high.
According to Jeanloz, who co-authored the paper, researchers used a “very intense pulse of light” to compress the sample in a process that took less than 10 nanoseconds.
The diamond used is a synthetically made polycrystalline diamond. According to Alex Hamza, a researcher with the Livermore lab who co-authored the study, the diamond is grown from a vapor of methane and hydrogen in a plasma reactor.
One application of this research is to check modern theories that predict the various properties of planets. For example, scientists can now test theoretical calculations regarding the mass of Jupiter’s and Saturn’s centers with experimental evidence, according to Princeton University professor of geosciences Thomas Duffy, who co-authored the study.
Ray Smith, a researcher with the Livermore lab who led the study, said the project began six years ago.
“People would have loved to do the experiment before but just didn’t have the experimental facility to do this kind of work,” Smith said. “Eighty years ago, there were theoretical models … but there have not been experimental models until now.”
The scientists have considered using other materials in future experiments, but for this particular study, they used carbon because it is the fourth-most abundant element in the universe and the only one that stays solid in all conditions, Jeanloz said.
According to Jeanloz, another application involves trying to find the origins of planets because they are the “platforms of life as we know it.” Additionally, the research applies to not only planets from the solar system but also those outside of it.
“At least one of the pieces of information we’d like to know about is, ‘What’s the likelihood that there’s life on some of these planets?’ ” Jeanloz said.
University of Arizona professor of planetary atmospheres and interiors William Hubbard said this technology will allow researchers to conduct more realistic experiments rather than using complicated calculations.
“What these experiments do is that they compare the data with the calculations … which is desirable to have confirmation as to whether they’re getting the right answer,” Hubbard said.