Science at the Extremes

When laboratory experiments began at the National Ignition Facility in 2010, researchers for the first time were able to study the effects on matter of the extreme temperatures, pressures and densities that exist naturally only in the stars and deep inside the planets. Results from this relatively new field of research, known as high energy density (HED) science, will mark the dawn of a new era of science. HED experiments at NIF promise to revolutionize our understanding of astrophysics and space physics, hydrodynamics, nuclear astrophysics, material properties, plasma physics, nonlinear optical physics, radiation sources and radiative properties and other areas of science (see Basic Research Directions for User Science at the National Ignition Facility, National Nuclear Security Administration and U.S. Department of Energy Office of Science, November 2011). Image of Black Hole in a Binary System An artist's concept of a black hole in a binary system shows a star (at right) feeding an accretion disk surrounding the black hole. The insert shows an image recorded by the Hubble Space Telescope of a massive black hole at the center of the galaxy NGC4261.

NIF will achieve temperatures of more than 100 million Kelvin (180 million degrees Fahrenheit); densities of about 1,000 grams per cubic centimeter; pressures more than 100 billion times as large as the Earth's atmosphere; and neutron densities as high as 10²⁶ per cubic centimeter. Only three places in the space and time of our universe have ever produced anything close to these conditions: the Big Bang, when the universe was born in a primordial fireball; the interiors of stars and planets; and thermonuclear weapons. Nothing within orders of magnitude of these extraordinary conditions has been available for laboratory experiments until now (see How to Make a Star). Because these conditions are so extreme, the connection between NIF and astrophysics is certain to excite scientists interested in using NIF to try to understand the objects in the cosmos, even to the beginning of the universe.

"Now is a very opportune time for major advances in the physics understanding of matter under extreme high energy density conditions."
–Committee on High Energy Density Plasma Physics,
National Research Council

Simulation of a Supernova Explosion Supernova explosion simulationThe temperature at which hydrogen undergoes fusion in the cores of stars for most of their lives is 10 to 30 million Kelvin, or 18 to 54 million degrees Fahrenheit – much lower than the temperature expected to be achieved in the NIF target. This phase of stellar evolution occurs at a density of some 100 grams per cubic centimeter, also well below what NIF will achieve. NIF's high pressures will permit planetary astrophysicists to study conditions at the cores of massive planets such as Jupiter and to understand the transition between large planets and stars. The extreme neutron density at NIF is larger than that achievedy by a core-collapse supernova – an exploding star – or when two neutron stars collide.

The conditions that NIF will produce will also permit research into:

Materials at unprecedented pressures, and the possible phase changes that are certain to be discovered under these conditions (see Planetary Physics).
Plasmas, the material that makes up the stars and constitutes almost all of the known matter in the universe (see Plasma Physics). The turbulent collections of electrons and ions that can carry electrical currents and generate magnetic fields are of interest not only for the production of energy from laser fusion, but also to astrophysics (much of our understanding of extreme objects, such as black holes, arises from studies of the X-rays emitted from the plasmas that are produced around them) and to nuclear physics (under conditions that are similar to those that exist in stars, unlike the usual accelerator-based experiments.).
Instabilities produced by laser fusion (see Laser-Plasma Interactions). Although these phenomena are the bane of laser fusion researchers, they are the same instabilities that are produced in some stellar objects, such as supernovae, and so will provide a unique opportunity for astrophysicists to understand what makes stars, even exploding stars, operate the way they do.

More Information

"Dawn of a New Era," Commentary by NIF Associate Director Edward I. Moses, Science & Technology Review, July/August 2007

"Preparing for the X–Games of Science," Science & Technology Review, July/August 2007

"At Livermore, Audacious Physics Has Thrived for 50 Years," Science & Technology Review, May 2002

Frontiers in High Energy Density Physics: The X-Games of Contemporary Science, Committee on High Energy Density Plasma Physics, National Research Council, 2003

Connecting Quarks with the Cosmos: Eleven Science Questions for the New Century, Board on Physics and Astronomy, National Research Council, 2003

"Science on the NIF," Energy & Technology Review, December 1994 (PDF)