The world's most powerful pulsed-power facility at Sandia National Laboratories, capable of producing 26 million amperes and extreme X-ray environments for fusion, weapons science, and high-energy-density physics research.
The Z Machine, formally known as the Z Pulsed Power Facility, is the most powerful laboratory radiation source on Earth. Located at Sandia National Laboratories in Albuquerque, New Mexico, it stores electrical energy in massive capacitor banks and discharges it in roughly 100-nanosecond pulses, delivering peak currents of approximately 26 million amperes (26 MA) to small experimental targets at its center.1
The Z Machine occupies a circular hall 33 meters in diameter. Its 36 Marx generator modules charge a water-insulated transmission line that converges radially toward a central target. When fired, the enormous current pulse flows through an array of fine tungsten wires (typically 100–400 wires, each thinner than a human hair) arranged in a cylindrical "wire array" or through a metal liner. The current vaporizes and implodes the array at velocities exceeding 100 km/s, generating a powerful Z-pinch that produces intense X-ray radiation.2
The resulting X-ray pulse, with peak power exceeding 350 terawatts and total energy above 2.7 megajoules, can heat and compress target materials to conditions found in the interiors of giant planets, in stellar explosions, and in nuclear weapons. The Z Machine underwent a major refurbishment in 1996 (from PBFA-II) and a further upgrade to its current "ZR" configuration completed in 2007, roughly doubling its energy output.1
Z's primary fusion approach is Magnetized Liner Inertial Fusion (MagLIF), a concept that combines elements of magnetic and inertial confinement. In a MagLIF experiment, a beryllium liner filled with deuterium fuel is first magnetized by an external field, then preheated by a laser pulse from the Z-Beamlet laser, and finally imploded by Z's enormous current pulse. The pre-magnetization and preheat help the fuel reach fusion conditions more efficiently than either approach alone.3
MagLIF experiments have produced thermonuclear neutron yields exceeding 1013, with ion temperatures above 3 keV, demonstrating that the concept works in principle. Scaling projections suggest that a next-generation pulsed-power driver with higher current could potentially reach fusion ignition conditions, though significant engineering challenges remain.4
The Z Machine's primary institutional mission is stockpile stewardship—validating the performance and safety of the U.S. nuclear weapons stockpile without underground testing. Its extreme conditions allow researchers to study material properties, radiation transport, and hydrodynamic phenomena at regimes inaccessible to any other laboratory facility.
The facility also supports equation-of-state experiments, dynamic material strength studies, and isentropic compression experiments (ICE) that can ramp-compress materials without shock heating—a unique capability. Z fires roughly 150–200 shots per year, each requiring several hours of reconfiguration between experiments. Sandia has explored concepts for a next-generation pulsed-power facility (sometimes called Z-Next) that could deliver 60+ MA and serve as a credible path to pulsed-power fusion energy.5