Dawn of a New Era
EXCITEMENT is building at the National Ignition Facility (NIF) and throughout the worldwide scientific community as Livermore researchers continue to commission laser beamlines and finalize experimental target designs. We are now just one year away from experiments using 96 laser beams and two years from experiments using NIF’s full constellation of 192 beams. Already NIF is nearing 2 million joules of laser energy in the main laser beams, a factor of 40 more than the operating energy of the previous largest lasers. Ignition experiments are fast approaching. Our goal in these shots will be to demonstrate the fusion process by which more energy is released from a 2-millimeter-diameter target filled with deuterium–tritium fuel than is deposited by the input from the huge NIF laser.
NIF represents bold and courageous thinking, and it represents the tenacious goal-oriented behavior of our Laboratory. Almost 50 years ago, John Nuckolls and colleagues first pointed the way to thermonuclear burn using laser drivers.
What is different about NIF besides its size and capabilities? All previous laser facilities were built with what was then the latest technology. Scientists were challenged to develop their research objectives within the capabilities of the facility. In contrast, NIF was designed with research goals in mind. It will be operated specifically to meet the needs of three crucial missions: to strengthen stockpile stewardship for a safe and reliable nuclear stockpile, to show the feasibility of inertial confinement fusion (ICF) as a clean source of energy, and to make significant strides in high-energy-density (HED) physics to understand the basic physical processes that drive the cosmos.
These three missions share the need to prepare materials at extreme conditions—pressures of up to 10 billion megapascals, temperatures of 100 million kelvins, and densities of 100 grams per cubic centimeter. These conditions occur in exploding nuclear weapons, in supernovae, and in the fusion reactions that power our Sun and the stars. One day, they may provide an inexhaustible power supply on Earth. Two compelling books published by the National Research Council, Connecting Quarks with the Cosmos: 11 Science Questions for the New Century and Frontiers in High Energy Density Physics: The X-Games of Contemporary Science, defined the challenges of HED research and set the stage for experiments on NIF.
The next set of NIF experiments, designed to study the energetics of ignition targets, is scheduled to begin this coming winter. These experiments are called Eos, after the Greek goddess of dawn. Eos is a fitting name because NIF represents the dawn of a new era in physics research, especially in the fields of HED science and ICF.
As described in the articles in this issue, NIF will create conditions in a laboratory that will allow scientists to thoroughly probe and diagnose extreme states of matter. Scientific progress is typically characterized by many small steps, each enlarging and refining previous knowledge. With NIF, we expect to make significant advances in several disciplines in a relatively short time. NIF will permit researchers to study astrophysical phenomena that are now physically inaccessible. We cannot venture inside stars or planets or go near black holes. Neither can we traverse billions of light years across the universe to examine a supernova explosion. However, with NIF, we can re-create, on a vastly smaller scale, the same physical processes that astronomers can only glimpse through a telescope. For the first time, we will be able to study fundamental physics processes and attempt to answer questions that have intrigued scientists for centuries.
In 2010, when ignition experiments are scheduled to begin, scientists will mark the golden anniversary of the first working laser. Soon after this laser came online, scientists developed the concept of ICF. But the road to NIF really began well before the laser was invented. It started with the Laboratory’s establishment in 1952. The vision of Livermore’s cofounders, Ernest O. Lawrence and Edward Teller, set the stage for our success. Lawrence conceived of big science and multidisciplinary teams organized to tackle the biggest physics challenges. Teller had a passionate interest in basic science for strengthening national security and expanding scientific understanding.
NIF is on the path of the courageous vision of our founders. The work we do on NIF will be key to our future as a premier international research laboratory.