Photonic Doppler velocimetry of ohmically exploded aluminum surfaces

Photonic Doppler Velocimetry (PDV) was used to investigate the exploding surface of coated metal driven by lineal current density increasing at 3 × 10 15 A/m/s. Aluminum-6061 rods were coated with three thicknesses ( 5 , 17, and 41 μ m) of Parylene-N and driven to 850 kA in approximately 100 ns, with the metal thicker than the skin depth. According to PDV, the metal surface melts at 85 ± 13 T and expands with a constant acceleration. Then, at a surface magnetic field of 140– 180 T, the metal acceleration begins to increase in time. Later, plasma forms on, and is correlated with PDV signal loss from, uncoated aluminum rods, 5- μ m-coated rods, and 17- μ m-coated rods, while no evidence suggests that plasma forms on 41- μ m-coated metal.

[1]  G. Hass,et al.  On the Preparation of Hard Oxide Films with Precisely Controlled Thickness on Evaporated Aluminum Mirrors , 1949 .

[2]  W. F. Gorham.  A New, General Synthetic Method for the Preparation of Linear Poly‐p‐xylylenes , 1966 .

[3]  F. Harris.  On the use of windows for harmonic analysis with the discrete Fourier transform , 1978, Proceedings of the IEEE.

[4]  Milani,et al.  Nonjellium-to-jellium transition in aluminum cluster polarizabilities. , 1989, Physical review letters.

[5]  Walt A. de Heer,et al.  The physics of simple metal clusters: experimental aspects and simple models , 1993 .

[6]  C. Munz,et al.  A tracking method for gas flow into vacuum based on the vacuum Riemann problem , 1994 .

[7]  E. Toro.  Riemann Solvers and Numerical Methods for Fluid Dynamics , 1997 .

[8]  R. Taylor,et al.  Thermophysical properties of molten aluminium alloys , 1998 .

[9]  Peter J. Shull,et al.  Nondestructive Evaluation: Theory, Techniques, and Applications , 2002 .

[10]  S. Rothman,et al.  Impedance match equation of state experiments using indirectly laser-driven multimegabar shocks , 2002 .

[11]  Laurent Guyard,et al.  UV–visible and infrared characterization of poly(p-xylylene) films for waveguide applications and OLED encapsulation , 2002 .

[12]  D. Mcdaniel,et al.  Effect of current rate on energy deposition into exploding metal wires in vacuum , 2004 .

[13]  Allen C. Robinson,et al.  Three-dimensional z-pinch wire array modeling with ALEGRA-HEDP , 2003, Comput. Phys. Commun..

[14]  D. Truhlar,et al.  Validation of Theoretical Methods for the Structure and Energy of Aluminum Clusters , 2004 .

[15]  Toh-Ming Lu,et al.  Chemical Vapor Deposition Polymerization , 2004 .

[16]  David R. Goosman,et al.  Velocimetry using heterodyne techniques , 2004, International Congress on High-Speed Imaging and Photonics.

[17]  O. Strand,et al.  Compact system for high-speed velocimetry using heterodyne techniques , 2006 .

[18]  Daniel H. Dolan,et al.  Accuracy limits and window corrections for photon Doppler velocimetry , 2007 .

[19]  Vincent T. Romero,et al.  Design, construction, alignment, and calibration of a compact velocimetry experiment , 2007, SPIE Optical Engineering + Applications.

[20]  Yangang Liu,et al.  Relationship of refractive index to mass density and self-consistency of mixing rules for multicomponent mixtures like ambient aerosols , 2008 .

[21]  D. Swift,et al.  Properties of plastic ablators in laser-driven material dynamics experiments. , 2007, Physical review. E, Statistical, nonlinear, and soft matter physics.

[22]  T. Awe,et al.  The Challenge of Wall–Plasma Interaction with Pulsed Megagauss Magnetic Fields , 2008 .

[23]  J. Porter,et al.  High current linear transformer driver (LTD) development at Sandia National Laboratories , 2010, 2009 IEEE International Conference on Plasma Science - Abstracts.

[24]  D. Dolan,et al.  Accuracy and precision in photonic Doppler velocimetry. , 2010, The Review of scientific instruments.

[25]  T. Awe,et al.  Threshold for thermal ionization of an aluminum surface by pulsed megagauss magnetic field. , 2010, Physical review letters.

[26]  T. Ao,et al.  Photonic Doppler Velocimetry Measurements of Materials Under Dynamic Compression , 2011 .

[27]  Mitigation of nonthermal plasma production to measure the pulsed magnetic field threshold for the thermal formation of plasma from thick aluminum surfaces a) , 2011 .

[28]  S. Chaikovsky,et al.  Stability of a nonlinear magnetic field diffusion wave , 2012 .

[29]  B. Blue,et al.  Tracking an imploding cylinder with photonic Doppler velocimetry. , 2013, The Review of scientific instruments.

[30]  Konstantin Lipnikov,et al.  Mimetic discretization of two-dimensional magnetic diffusion equations , 2013, J. Comput. Phys..

[31]  Ory Schnitzer,et al.  Fast penetration of megagauss fields into metallic conductors , 2014 .

[32]  M. Desjarlais,et al.  Frontiers and challenges in warm dense matter , 2014 .

[33]  T. Awe,et al.  Electrothermal instability mitigation by using thick dielectric coatings on magnetically imploded conductors. , 2014, Physical review letters.

[34]  A. Mathewson,et al.  Crystallinity and mechanical effects from annealing Parylene thin films , 2016 .

[35]  Brian J. Kim,et al.  Micromachining of Parylene C for bioMEMS , 2016 .

[36]  R. Mcbride,et al.  Experimental Demonstration of the Stabilizing Effect of Dielectric Coatings on Magnetically Accelerated Imploding Metallic Liners. , 2016, Physical review letters.

[37]  T. Awe,et al.  On the Evolution From Micrometer-Scale Inhomogeneity to Global Overheated Structure During the Intense Joule Heating of a z-Pinch Rod , 2017, IEEE Transactions on Plasma Science.

[38]  T. Awe,et al.  Experimental observation of the stratified electrothermal instability on aluminum with thickness greater than a skin depth. , 2018, Physical review. E.

[39]  W. Zou,et al.  Investigation of surface evolution for stainless steel electrode under pulsed megagauss magnetic field , 2018 .

[40]  D. B. Rogozkin,et al.  Application of photon Doppler velocimetry for characterization of ejecta from shock-loaded samples , 2018, Journal of Applied Physics.

[41]  L. Berthe,et al.  PDV-based estimation of ejecta particles' mass-velocity function from shock-loaded tin experiment. , 2018, Review of Scientific Instruments.

[42]  J. Brown,et al.  Uncertainties in cylindrical anode current inferences on pulsed power drivers , 2018, Physics of Plasmas.

[43]  M. Adams,et al.  Enhancing cylindrical compression by reducing plasma ablation in pulsed-power drivers , 2019, Physics of Plasmas.

[44]  R. Mcbride,et al.  Reduction of ablated surface expansion in pulsed-power-driven experiments using an aerosol dielectric coating , 2019, Physics of Plasmas.

[45]  R. S. Bauer,et al.  Significant change in threshold for plasma formation and evolution with small variation in copper alloys driven by a mega-ampere current pulse , 2019, Physics of Plasmas.