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NNSA, LANL Announce Successful First Dual-Axis Hydrodynamic Test

DARHT facility captures five X-ray images and other test data in unprecedented simultaneous use of two electron accelerators

WASHINGTON, D.C. - The National Nuclear Security Administration (NNSA) announced today that Los Alamos National Laboratory (LANL) fired its first-ever double-viewpoint hydrodynamic test of a nuclear weapon component mockup.  The test, conducted by LANL scientists and engineers, took place at the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos.
"This successful dual-axis hydrodynamic test is an important development in the NNSA's stockpile stewardship mission," said Brig. Gen. Garrett Harencak, NNSA principal assistant deputy administrator for military application. "The multiple X-ray images provided by this world class experimental facility will inform the critical work of our scientists and engineers across the nuclear security enterprise."

The test is part of the National Nuclear Security Administration's stockpile stewardship program, which uses cutting-edge science, technology, and engineering to experimentally confirm predictions of weapons performance made from computational simulations. This allows NNSA to ensure the safety, security, and effectiveness of the nation's nuclear deterrent without nuclear testing. 

"Initial indications show excellent data return," said the hydrodynamic experiments division leader, David Funk.  "The baseline experiment captured five time-dependent X-ray images and a variety of data from other diagnostics of pressure, temperature, and timing.  This data provides the nation with one of the most rigorous tests of our capability to predict weapons performance."

Conducted inside a specially designed double-walled containment vessel, the test used high explosives to drive an implosion of a duplicate component made from non-nuclear surrogate materials.  As the mockup is imploding, the DARHT facility fires two electron accelerators positioned at a 90-degree angle from one another to generate high-power X-rays that are used to create multiple images of the imploding device's inner workings, which are then compared with computer predictions.

The DARHT team solved a variety of technical challenges in the months and years leading up to this experiment.  "While the first axis of DARHT has been functioning nearly flawlessly for more than 10 years, the second axis is still an operational prototype of the world's longest pulsed electron linear accelerator, so the challenges have been monumental," said Funk.  "Just fitting the accelerator in the building had its challenges, leading to the use of a novel material with an exceptionally high magnetic field strength. Using standard materials would have required the accelerator to be five times bigger than it is, and it would not have fit in the building."
Other challenges included designing a cathode injector system that would supply enough electrical current to the accelerator and developing a target that is robust enough to survive four pulses from the extremely high-energy electron beam of the second axis.
"I couldn't be more proud of our team's accomplishments preparing and conducting this first test," said Funk.  "The test marks the beginning of what will be a very long operational lifetime for this important diagnostic tool in support of national security."

About Los Alamos National Laboratory (

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and the Washington Division of URS for the Department of Energy's National Nuclear Security Administration.
Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.

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Established by Congress in 2000, NNSA is a separately organized agency within the U.S. Department of Energy responsible for enhancing national security through the military application of nuclear science.  NNSA maintains and enhances the safety, security, reliability and performance of the U.S. nuclear weapons stockpile without nuclear testing; works to reduce global danger from weapons of mass destruction; provides the U.S. Navy with safe and effective nuclear propulsion; and responds to nuclear and radiological emergencies in the United States and abroad.  Visit for more information.

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