The Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) is a facility at Los Alamos National Laboratory which is part of the Department of Energy's stockpile stewardship program. It uses two large X-ray machines to record three-dimensional interior images of materials. In most experiments, materials undergo hydrodynamic shock to simulate the implosion process in nuclear bombs and/or the effects of severe hydrodynamic stress. The tests are described as "full-scale mockups of the events that trigger the nuclear detonation". The powerful pulsed X-ray beams allow for an ultra-fast motion picture to be constructed showing the details of the process being studied in three dimensions. The tests are often compared with computer simulations to help improve the accuracy of the computer code. Such testing falls under the category of sub-critical testing. History Planning for DARHT began in the early 1980s. Based upon the success of Livermore's FXR, induction-linac facility, in 1987 Los Alamos chose the same type of accelerator to replace PHERMEX, an RF accelerator commissioned in 1963. The project became an important priority after the United States stopped testing nuclear weapons in 1992. Approval for an overhaul and new axis came in stages, with the first axis approved for construction in 1992 and the second axis (initially to be a twin of the first) in 1997. This plan was changed when the Department of Energy decided it wanted the second axis to deliver not one view of the implosion, but a series of views in rapid succession. Construction was halted between 1995 and 1996 due to lawsuits by Los Alamos Study Group and Concerned Citizens for Nuclear Safety, two anti-nuclear weapons organizations demanding that the laboratory produce an Environmental Impact Statement for its construction and operation. Activists argued that DARHT is in violation of the Comprehensive Test Ban Treaty and potentially the Nuclear Non-Proliferation Treaty, though the lab and the DOE reject this view. When completed in 1999, the first-axis accelerator produced a 60ns electron pulse with a current of 2 kA and an energy of 20 MeV focused to 1mm diameter spot on the target - the smallest spot size and shortest pulse length ever achieved at that intensity. As a result, image quality was about three times higher than at Livermore's FXR facility. The second machine (second axis) is more complicated and, when first completed in 2003, was found to be unusable due to electrical breakdown. The origin of the electrical