Nearly 50 years later, stars power up
Never abandoned, always on the verge of the extraordinary, laser fusion approached fait accompli last month when Lawrence Livermore National Laboratory powered up the world’s most powerful laser facility, the National Ignition Facility (NIF), for its initial experiments.
The facility’s 192 giant lasers, housed in a 10-story building the size of three football fields, will, when fully operational, focus 500 trillion W of power onto a pellet of hydrogen fuel. The experiments will create conditions resembling those that exist only in the cores of stars and giant planets or inside a nuclear weapon.
The prospects of NIF and other fusion facilities around the world have spurred researchers to anticipate testing a number of theories using results derived from the experiments. Clean energy is one. Another is a better understanding of how stars and supernovae originated and developed. Yet another is how extreme temperatures and pressures at the cores of planets affect matter.
Last year at the Rutherford Appleton Laboratory’s Central Lasers Facility in the UK, the Vulcan Laser concentrated power and heated matter to an astounding 10 million degrees C – demonstrating concepts that could be key to building a future nuclear fusion reactor. A €10 billion experimental reactor (ITER) is being built in France and is expected to be completed in 2018.
Another facility in France, called “PETAL” for PETawatt Aquitaine Laser, uses a high-energy multi-petawatt laser to generate pulses of up to 3.5 kJ with a duration of 0.5 to 5 ps. PETAL is the forerunner of the UK’s HiPER, the brainchild of 26 institutions from 10 countries. HiPER is expected to facilitate new areas of science, including extreme material studies, astrophysics in the laboratory, miniaturized particle accelerators and expanded fundamental physics research.
In fact, the most recent achievements in laser fusion have caused the department of physics at the University of York to become the first in the UK to offer a fusion energy master’s degree. The first semester begins in October 2009.
Laser-driven inertial confinement fusion (ICF) has always been about power. From the 1960s to now, Lawrence Livermore has created a string of ICF lasers: Janus, Cyclops, Argus, Shiva, Omega, Novette and Nova. Each failed to achieve ignition, yet every experiment produced success by broadening knowledge of the process and the many areas in which it could boost science and technology.
Some news reports anticipate that a commercial laser-powered nuclear fusion reactor could be up and running in the next 20 or 30 years. If that’s true, we can look forward to a new era in environmental and planetary science. Certainly, the ICF technology has been well worth the wait.
- laser fusion
- Optical confinement of matter with high field energies intended to induce a stable nuclear fusion interaction.
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