The achievement of fusion ignition with high energy gain requires the symmetric and stable compression of thermonuclear fuel. However, internal defects in the capsule can disrupt this process by seeding nonlinear hydrodynamic instabilities during implosion, which degrade the overall performance. Numerical simulations reveal that the application of a magnetic field can effectively suppress the development of hydrodynamic instabilities caused by isolated defects, thereby reducing bubble penetration depth. This study investigates the evolution of a micrometer-scale, low-density internal defect in a planar high-density-carbon capsule under the X-ray drive in the presence of a magnetic field. Both theoretical and simulation analyses indicate that the external magnetic field introduces a new vortex generation mechanism that counteracts defect-induced vortices, thereby mitigating the growth of nonlinear hydrodynamic instabilities. This suppression reduces the mixing of ablator material into the hot spot, improving the potential for high energy gain in inertial confinement fusion.

isolated defects, hydrodynamic instabilities, radiation-driven, magnetic field