Multimegavolt multiaxis high-resolution flash X-ray source development for a new hydrodynamics research facility at AWE Aldermaston

The Atomic Weapons Establishment, Aldermaston, U.K., has a number of pulsed-power-driven flash X-ray machines for diagnosing the hydrodynamics of explosively-driven high-atomic-number materials. The most powerful of these machines is Mogul-E, which operates at about 10 MV and 30 kA, delivering about 400 R at 1 m in a 5-mm spot. Longer-term plans envisage the upgrading of existing facilities through the construction of a hydrodynamic research facility (HRF) with multiaxis radiography. It is proposed that the HRF will be furnished initially with three inductive voltage adder (IVA) machines operating at ~14 MV, each giving 600 R at 1 m in a 5-mm spot. It is envisaged that, following further research, the outputs will be increased towards 1000 R, with a reduction in X-ray spot size. More speculative proposals involve increasing the number of machines from three to five, and/or the splitting of the output end of one or more machines to drive more than one X-ray source per machine. An overview of the research programme necessary to achieve these aims is presented. Topics covered include: experiments to investigate the performance at ~5 MV of the paraxial diode and the magnetically immersed diode; split magnetically insulated transmission lines where one machine drove two X-ray sources; the design and testing of a prototype IVA module operating at ~1.5 MV; the design of an upgrade from 5 MV to 10 MV of one of our existing single pulse-forming-line machines; and initial experiments to investigate the usefulness of ultrashort-pulse lasers for generating useful fluences of 2-4 MeV X-rays