Obtaining a burning plasma is a critical step towards self-sustaining fusion energy. 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 (NIF), 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 capsule through two different implosion concepts developed at the NIF.
The experiments show fusion self-heating in excess of the mechanical work injected into the implosions, satisfying several burning-plasma metrics. These groundbreaking results provide an opportunity to study α-particle-dominated plasmas and burning-plasma physics in the laboratory.
For more info see Zylstra et al., Nature 601 (27 January 2022), 542.
Source: www.nature.com
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