UNCLASSIFIED Hydrodynamics at AWE David Chambers – Head of Hydrodynamics UNCLASSIFIED UNCLASSIFIED Outline  Size and Structure of Hydrodynamics Department (HD)  Facilities we operate  Radiographic Diagnostics  Analysis Techniques  Pulse Power Research UNCLASSIFIED UNCLASSIFIED Hydrodynamics is the science of forces acting on or exerted by fluids. When explosively compressed nuclear warheads behave like fluids Experiments are conducted using explosives to drive metals. Data collected and analysed using a range of diagnostics AWE core capability that delivers its primary mission through the provision and analysis of data UNCLASSIFIED UNCLASSIFIED Hydrodynamics Division  ~200 personnel  50% science, engineering & technology  30% facilities engineering and enabling functions  20% management and overhead  ~150 trials conducted/yr  8 “major” trials  25 “minor” or “physics” trials  120 non-explosive trials UNCLASSIFIED UNCLASSIFIED Current H-area Explosive Facilities  Circa 1950s construction  Requiring regular – and deep – maintenance to remain compliant UNCLASSIFIED UNCLASSIFIED Chamber Set-up Before and After UNCLASSIFIED UNCLASSIFIED Diagnostics - Radiographic Facilities - MOGUL E: 400R, 10million volts, 5mm spot - MOGUL D: 150R, 4mm spot - MINI B: 12R, 2.5mm spot - MEVEX: 1R, 0.8 MV, 2.5mm spot, P5 - S. SWARF: 60R, 4mm spot UNCLASSIFIED UNCLASSIFIED Pulse Power Research and Development  Self Magnetic Pinch (SMP) selected as the source for the IVA in 2006  Since 2006, an engineering design has been developed for the diode on the IVA driver.  Much of the development work was carried out on RITS6 at SNL as this is a very similar driver to the IVA Diagram components: Field shaper, Vacuum vessel, Shielding, Anode fine movement adjustment, Alignment windows (x4), Anode assembly, Cathode, MITL UNCLASSIFIED UNCLASSIFIED Pulse Power Research and Development  We have been implementing new plasma modelling techniques into SMP diode simulations - Anode plasma evolution - Cathode plasma evolution UNCLASSIFIED UNCLASSIFIED AWE 70mm gas gun The AWE gas gun is used to produce dynamic data and develop experimental techniques in support of the development and validation of material models. Research areas include: Equation of State, Strength, Friction, Ejecta. Single stage Helium gas gun: • 3m bore, 70mm diameter barrel • Capable of impact velocities 150-900 m/s • 1D plate impact experiments • ISP 4kg - ~860m/s Diagnostics: • Velocimetry - HetV, • Timing - electrical pins, ionisation pins, piezo pins • Stress - Manganin stress gauges • Ductility/Fracture – High speed photography UNCLASSIFIED UNCLASSIFIED Institute of Shock Physics (ISP) Capabilities - 100mm Gas Gun - MACH (Mega Ampere Compression & Hydrodynamics) - Electrothermal launcher - Gas loader for DAC UNCLASSIFIED UNCLASSIFIED High Speed Photography  Cordin Digital camera 570-74  Cordin 121 max camera speed, Framing 7.5 x 10^6 fps, 30mm/µs UNCLASSIFIED UNCLASSIFIED Non-Radiographic Diagnostics - Optical Velocimetry: Capability Well established; HetV technique beginning to replace F-P - Stress Gauges: Regularly deployed on Gas Gun experiments (Longitudinal & Lateral Stress Gauges, 6 mm, 2 mm from impact) - Line VISAR (spatially resolved velocity): Under development (Engaged with Academia/ISP) - PDA: Under development for particle size measurement - Spectroscopy: Established to study diode performance - Piezo-electric Gauges: Routinely fielded on ejecta experiments (Piezoelectric Disc PZT or Lithium Niobate 1.3 mm diameter, 0.5 mm thick, Brass, Kynar® PVDF, Silver-loaded Epoxy Layer, Vapour Deposited Copper Layer) - Pyrometry: Newly established capability (Gas Gun Experiments) [Planck: I = f(λ, T)] UNCLASSIFIED UNCLASSIFIED HE Performance Experiments Cylinder tests: - Investigation EoS Detonation products - Investigation into next generation diagnostics ongoing Rate stick tests: - HE performance (V-o-D / Wave curvature) Shock to detonation: - Magnetic gauge technique - To be deployed on ISP HE gas gun (PhD) Corner Turning: - Study of non-Ideal Explosives UNCLASSIFIED UNCLASSIFIED HE Driven Damage / Physics experiments HE driven coupon experiments: - Strength/spall investigation - Radiography - Velocimetry Fracture code validation experiments: - Radiography - High speed imaging - Newly established CCD Imaging system HE driven coupon experiments: - Ejecta production - Velocimetry - Piezo-electric probes - Foil probes - High speed imaging - Spectroscopy - radiography Jet Penetration studies: - Jet characterisation - Radiography - Jet stopper techniques UNCLASSIFIED UNCLASSIFIED Non-HE Physics Experiments Gas Gun experiments: EoS Data - Currently use D16 SS Gun (0.9km/s: 70mm Bore) - Limited in pressure range required - Future: ISP SSG (1.3km/s: 100mm Bore) and ELC 2SG later - Metals & alloys; EoS data for relevant and simulant materials (Ta & TaW, Pb & PbSb, Ti & Ti64, WHA, SS-2169) Gas Gun experiments: - Study of friction at metal interface - Wave Profile Experiments (HetV and Piezo experiments) - Ejecta Production studies - Shear strength studies using lateral manganin stress gauges - Polycrystalline studies employing Line Visar UNCLASSIFIED UNCLASSIFIED Non-HE Physics Experiments - Linear Shock Tube: Operation re-established – Mix experiments. Use as R&D tool for quantitative turbulent mixing diagnostics - Convergent Shock Tube: Operational system Imminent. Capability to conduct shadowgraphy on turbulent mixing. - High pressure compression data on metals: - P,T melt curve for metals at high pressure (laser heating) - Pu, U, Ta, Ti, V, PbSb, Ti64, Etc… - Pressure up to 1 Mbar + - Joint collaborations with LLNL, Edinburgh, UCL - Synchrotron beam time through collaborations UNCLASSIFIED UNCLASSIFIED Image Analysis - Forward Modelling  Make an estimate of the object  Simulate the radiograph that would result from this object  Iteratively change the object until the calculated dose agrees with the experimental dose Due to experimental uncertainties solution non unique Image Analysis aims to find the most probable solution Using ‘prior knowledge’ to reject unlikely solutions UNCLASSIFIED UNCLASSIFIED Summary Essential capability to support AWE Mission  Clear & Enduring UK need for Hydro data  Unique UK testing facilities  Unique ultra-high speed diagnostics  Wide range of different types of Hydrodynamic Experiment carried out  Strong & active area of international collaboration UNCLASSIFIED