Fast Ignition: An Alternative Route to Inertial Confinement Fusion

Fusion holds the promise of being a safe and inexpensive energy source for the future, essentially burning deuterium obtained from heavy water to produce power in much the same way stars generate their energy. While a “Mr. Fusion Home Energy Reactor” device is still extremely unlikely in the foreseeable future, significant progress has been made, and large fusion devices are now beginning to appear. In particular, Inertial Confinement Fusion (ICF), where a laser is used to implode a Deuterium-Tritium (DT) pellet to obtain a net energy gain, is poised to take a major step forward in the next few years. This progress, coupled with the rapid technological advances in high power lasers and computer simulation capabilities, has also spawned a number of new ideas related to ICF. In particular, a new concept known as “Fast Ignition”, where lasers are used to rapidly heat a pre-compressed pellet of DT, looks promising as an alternative, though more speculative, route to fusion energy. This method of fusion relies heavily on the interaction of ultra-intense laser pulses with plasmas and solids to generate intense relativistic electron beams, the study of which has already produced many exotic spin-offs such as novel ion accelerators, warm dense matter sources, and electron-positron pair plasmas for use in laboratory astrophysics experiments.

Presenter(s)

Dr. Wilks received his B.A. degree in physics from U.C. Berkeley and his PhD. in plasma physics from U.C.L.A. in 1989 under the supervision of John Dawson. Since then, he has been a research scientist at Lawrence Livermore National Laboratory. His area of expertise is the application of computer simulation to the design and analysis of high intensity laser matter experiments. His work on applying Particle-In-Cell simulations to ultra-intense laser solid density plasma interactions led to several theoretical predictions about the interactions which were subsequently verified in experiment: namely, the ponderomotive scaling of hot electron temperatures, the presence of hundreds of megaGauss magnetic fields and hole boring of the laser pulse. This work played a key role in the early development of the fast ignitor concept. Recent work includes the development of a physical picture of ion acceleration, dubbed Target Normal Sheath Acceleration (TNSA). In 2002, he was awarded the Defense Programs Award of Excellence for his role in developing a novel hydrodynamics experimental campaign and the American Physical Society 2006 Award for Excellence in Plasma Physics Research (along with 4 other scientists, 2 from Japan, 1 from UK, and another from LLNL). Currently, he is investigating novel methods of creating high density, high temperature plasmas for laboratory astrophysics experiments. He is a lifetime member of the American Physical Society.