Inertial confinement fusion

Nuclear engineering

Optics

Physics

Engineering

Philosophy

Radiation

Fusion

Ignition system

Atomic physics

Nuclear physics

Materials science

Implosion

Fusion power

National Ignition Facility

Linguistics

Laser

Thermonuclear fusion

Plasma

Thermodynamics

Nature

Obtaining a burning plasma is a critical step towards self-sustaining fusion energy1. A burning plasma is one in which the fusion reactions themselves are the primary source of heating in the plasma, which is necessary to sustain and propagate the burn, enabling high energy gain. After decades of fusion research, here we achieve a burning-plasma state in the laboratory. These experiments were conducted at the US National Ignition Facility, a laser facility delivering up to 1.9 megajoules of energy in pulses with peak powers up to 500 terawatts. We use the lasers to generate X-rays in a radiation cavity to indirectly drive a fuel-containing capsule via the X-ray ablation pressure, which results in the implosion process compressing and heating the fuel via mechanical work. The burning-plasma state was created using a strategy to increase the spatial scale of the capsule2,3 through two different implosion concepts4–7. These experiments show fusion self-heating in excess of the mechanical work injected into the implosions, satisfying several burning-plasma metrics3,8. Additionally, we describe a subset of experiments that appear to have crossed the static&nbsp;self-heating boundary, where fusion heating surpasses the energy losses from radiation and conduction. These results provide an opportunity to study α-particle-dominated plasmas and burning-plasma physics in the laboratory. A burning plasma, a critical step towards self-sustaining fusion, is achieved at the US National Ignition Facility, with a subset of experiments demonstrating fusion self-heating beyond radiation and conduction losses.

Burning plasma achieved in inertial fusion