REVISTA DYNA ENERGÍA

The goal is to make tiny, pea-sized capsules capable of withstanding temperatures hotter than the Sun and pressures comparable to Jupiter’s core, operating at high repetition rates in a future commercial fusion power plant. Current capsule designs are expensive, hard to mass-produce, and very sensitive to microscopic defects that can disrupt compression and reduce fusion yield.?

At SLAC, researchers have tested capsules made from 3D-printed foams created by two-photon polymerization, a very light structure that can hold cryogenic deuterium–tritium fuel. Using the Linac Coherent Light Source and the Matter in Extreme Conditions instrument, they subjected carbon samples and these foams to laser-driven shocks and ultrashort X-ray pulses, measuring temperature, density, shock propagation and internal 3D structure. These measurements help validate and refine computer simulations that predict how capsules deform and compress during a fusion shot.?

One study combined spectroscopy and scattering (Thomson scattering and fluorescence spectroscopy) to track how carbon transitions from solid to plasma on ultrafast timescales, clarifying the earliest phase of the implosion. Another examined how shock waves travel through printed foams compared with traditional aerogels, generating data to guide more robust and uniform capsule designs. Using ptycho-tomography, teams reconstructed 2D and 3D images of structures only tens of microns across, identifying pores, voids and imperfections that affect implosion symmetry. In a further study, researchers deliberately introduced controlled defects into capsule shells to see how they degrade compression, helping to define realistic manufacturing tolerances.?

These efforts sit within U.S. Department of Energy programs aimed at accelerating inertial fusion energy science and technology, in collaboration with universities and other national labs. They build on repeated ignition results at the National Ignition Facility, which have shown that fusion can yield more energy than the driving lasers, shifting the focus from “is it possible?” to “how do we make it reliable, affordable and continuous?”. Understanding and optimizing capsule materials is a necessary step to move from occasional experiments to systems firing and replacing targets at high cadence, a fundamental requirement for a practical fusion power plant