Now enters new phase of readiness tests in preparation for first dual axis experiment this summer
The Laboratory's Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is fully operational, according to a news release from the National Nuclear Security Administration.
"DARHT is an incredible scientific and engineering achievement and is extremely important to certifying the nuclear weapons stockpile," said Robert Smolen, NNSA deputy administrator for defense programs. "U.S. nuclear weapons are 20 to 30 years old, and this high-tech machine allows us to look at how changes made to fix age-related and technical defects may affect weapon performance - all without conducting an underground nuclear test."
"The dedication and hard work by the entire DARHT team cannot be underestimated," said Charles McMillan, associate director for weapons physics (ADWP). "Many seemingly insurmountable technical challenges were encountered along the way, but the team rose to the occasion each time, solving the problems and ultimately reaching this important day."
DARHT, located at Technical Area 15, consists of two electron accelerators positioned at a 90-degree angle, each focused on a single firing point. It is at this point where nuclear weapon mock-ups are driven to extreme temperatures and pressures with high explosives and where the DARHT electron beams produce high-energy X-rays used to image the behavior of materials and systems under those extreme conditions. Last year these experiments moved into fully contained steel vessels to better protect the environment and improve experiment turnaround time.
The technical demands of the second axis are one-of-a-kind -- a 17-million-volt electron beam lasting for 1.5 millionths of a second, which is sliced into four pulses -- each lasting less than 100 billionths of a second, creating four X-ray pulses. These X-rays are used to image materials moving at 10,000 miles per hour with densities that exceed those at the center of the Earth.
The DARHT second axis provides the nation with a unique, world-class scientific facility with the potential to not only provide four-frame "movies" of tests but also to give scientists the data to create the first-ever three-dimensional images -- critical data to meet the needs of the stockpile for decades to come.
Each Axis 2 cell is a 15,000-pound doughnut-shaped aluminum structure with an internal configuration of magnetic material and insulating oil. At the center of each cell is a high-voltage, vacuum-insulated beamline. The structures allow operators to add voltage in steps to an electron beam, accelerating it to very high energy and eventually slamming it into a dense target to create X-rays. Electronic detectors turn the X-rays into high-speed digital images of mock nuclear weapon components at detonation. Axis 2 consists of 74 individual accelerator cells.
