Domain overview
Inertial and pulsed-power approaches to fusion
Original Fusenergy explanation, framed against public technical references. Educational, not engineering or investment advice.
Inertial fusion takes the opposite strategy to magnetic confinement: instead of holding a dilute plasma for seconds, it compresses a millimetre-scale fuel capsule to enormous density for a few billionths of a second, letting the fuel’s own inertia confine it while it burns. In December 2022 the National Ignition Facility reached target gain above one — more fusion energy out of the capsule than the laser delivered to it — a scientific milestone that also exposed how far the driver efficiency and repetition rate remain from a power plant.
Getting there depends on symmetry and drive. Compression must be almost perfectly spherical, because small imperfections grow through hydrodynamic instabilities and quench the implosion; direct-drive, indirect-drive (hohlraum), and magnetized-target schemes each trade symmetry, efficiency, and complexity differently. Alpha self-heating inside the compressed hot spot is the same physics that a magnetic burning plasma needs, just on a nanosecond timescale.
Pulsed-power and magneto-inertial concepts — Z-pinches, MagLIF, and repetitive pulsed drivers — pursue efficiency by using electrical current rather than lasers. The ten topics here span laser compression, target symmetry and fabrication, driver efficiency, repetition rate, chamber clearing, and Z-pinch stability. Read across the six lenses to separate a single high-gain shot from the sustained, high-repetition, high-efficiency operation a plant would require.
Ignition versus a power plant
A target gain above one is a physics result. Plant-level engineering gain must also pay for an inefficient driver and run many times per second, which is a far higher bar.
Symmetry and instabilities
Implosions must stay near-spherical; Rayleigh–Taylor and mix instabilities from small asymmetries or target defects are the dominant failure mode for high gain.
Repetition rate and chambers
Lab facilities fire a few shots a day; a plant needs several per second, with targets mass-produced and the chamber cleared and protected between every shot.