Inertial fusion energy
In inertial fusion energy (IFE) the burning nuclear fusion reaction is ignited by illuminating and compressing a target – a pellet that contains deuterium and tritium – by the use of intense laser or ion beams. A power reactor would operate by igniting several such pellets per second.
A favorable feature of inertial fusion is that the components (target factory, driver, fusion chamber) can be isolated from each other. In addition, the driver can be modular, thereby enabling a staged development. As is the case for magnetic fusion energy, progress in inertial fusion has been remarkable.
The scientific basis of inertial fusion has progressed to the point where the driver and pellet requirements to achieve ignition are known to high confidence and are within reach. Experimental diagnostics are capable of probing details of physical properties under extreme conditions. Knowledge of the laser-plasma interaction and implosion hydrodynamics has progressed from a rudimentary empirical level, with much uncertainty, to a current state in which there is good agreement between theory and experiment. Significant advances in computational power and technique, in
concert with experiments, have led to good predictive capability.
At the same time, laser driver technology has progressed from a few joules to megajoules, with sufficiently good beam control and pulse characteristics to implode ignition pellets. Likewise, advances in technology to fabricate complex targets with nearly sufficient surface smoothness to satisfy the program requirements have been remarkable. The United States is clearly the world leader in such research. The Laboratory for Laser Energetics performs much research on this type of fusion.
There is a high level of confidence that ignition-level performance will be achieved on the National Ignition Facility (NIF), now under construction at Lawrence Livermore National Laboratory. But the challenges that must be overcome to achieve a practical IFE reactor are at least as large as those before MFE. A practical fusion reactor would require large extrapolations of performance in numerous areas, including driver technology, pellet fabrication costs, and reactor wall technology.
A variety of drivers are being explored (several types of lasers, heavy ion beams, and plasma physics, magnetic fusion energy
