X-rays are utilized to compress nuclear fuel for fusion reactions through a process involving radiation pressure, where the momentum of photons exerts force on matter. Although photons lack charge, they can still impart momentum, causing the outer layer of the fuel to absorb energy and transform into a high-temperature plasma. This plasma expands rapidly, resulting in an inward force that compresses the remaining fuel, creating conditions necessary for fusion. The National Ignition Facility (NIF) employs this method by converting UV light to X-rays to achieve a more uniform illumination. This implosion effect is critical for reaching fusion breakeven conditions.