Diamond fusion fuel capsules' flaws decoded to ‘maximize’ energy output

Scientists at the University of California San Diego have experimentally observed, for the first time, shock-induced amorphization in diamond—a structural transformation previously predicted only by simulations. Their study reveals that diamond capsules used in inertial confinement fusion experiments, such as those at the National Ignition Facility, develop structural flaws under extreme pressures generated by powerful laser-driven shock waves. These defects range from subtle crystal distortions to complete disorder (amorphization), which can disrupt the symmetry of the implosion process critical for maximizing fusion energy output. The research demonstrated that at pressures around 69 gigapascals (GPa), diamond undergoes only elastic deformation, maintaining its lattice integrity. However, at higher pressures near 115 GPa, high shear stresses induce defects like stacking faults, dislocations, twins, and eventually amorphization. This brittle behavior of diamond under shock conditions complicates analysis but is crucial for understanding how to improve capsule design. The findings provide valuable insights into the deformation mechanisms of diamond and similar cov