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In many inertial confinement fusion experiments, the neutron yield and other parameters cannot be completely accounted for with one and two dimensional models. This discrepancy suggests that there are three dimensional effects which may be significant. Sources of these effects include defects in the shells and shell interfaces, the fill tube of the capsule, and the joint feature in double shell targets. Due to their ability to penetrate materials, X-rays are used to capture the internal structure of objects. Methods such as Computational Tomography use X-ray radiographs from hundreds of projections in order to reconstruct a three dimensional model of the object. In experimental environments, such as the National Ignition Facility and Omega-60, the availability of these views is scarce and in many cases only consist of a single line of sight. Mathematical reconstruction of a 3D object from sparse views is an ill-posed inverse problem. These types of problems are typically solved by utilizing prior information. Neural networks have been used for the task of 3D reconstruction as they are capable of encoding and leveraging this prior information. We utilize half a dozen different convolutional neural networks to produce different 3D representations of ICF implosions from the experimental data. We utilize deep supervision to train a neural network to produce high resolution reconstructions. We use these representations to track 3D features of the capsules such as the ablator, inner shell, and the joint between shell hemispheres. Machine learning, supplemented by different priors, is a promising method for 3D reconstructions in ICF and X-ray radiography in general.

The PHELIX Liner Demonstration Experiment (PLD-1) took place in September of 2010 at Los Alamos National Laboratory. The PHELIX machine consists of a 500 kJ single-marx capacitor bank cable-coupled to a toroidal 1:4 current step-up transformer which delivers multi-Mega- Ampere currents to a cm size load. In this experiment the load consisted of a 3 cm radius, 0.8 mm thick, 3 cm tall aluminum liner, copper glide planes, a thin polyethylene insulator, and a 0.5 cm thick aluminum return conductor. Two independent channels of fiber optic Faraday rotation measured a peak load current 4 MA with a pulse width of 10 s. Four linear Rogowski coils measured the output current of the 4 marx modules. High-resolution flash X-radiography imaged a stable, highly symmetric and uniform liner 14.5 s after current start. A 12 channel laser Doppler velocimetry (LDV) system tracked the inside surface of the liner throughout the experiment and showed a peak velocity before impact with probes of 1 km/s. The LDV probes were arrayed axially as well as azimuthally and confirmed the symmetry of the liner trajectory. Surprisingly, the LDV showed distribution of velocities of the inner liner surface late in time. PLD-1 is the first step towards utilizing the PHELIX pulsed-power system at the Los Alamos proton radiography facility., See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th). Held in San Francisco, CA on 16-21 June 2013., The original document contains color images.

The PHELIX pulsed power project will introduce magnetically driven hydrodynamics experiments to the Los Alamos National Laboratory s proton radiography facility (pRad). The Precision High Energy-density Liner Implosion eXperiment (PHELIX) has been commissioned at Los Alamos. A small footprint capacitor bank consisting of four parallel connected single-stage marx units (500 kJ) is cable coupled to a toroidal, current stepup transformer to deliver multi-Mega-Ampere, 10 s current pulses to cm size cylindrical loads. In a sequence of tests the performance of each component (capacitor bank and transformer) was evaluated and compared to a circuit model. The transformer coupling was observed to be k 0.93. The tests culminated in a liner implosion experiment in which an 3 cm radius, 0.8 mm thick, 3 cm tall aluminum liner was accelerated to a velocity of 1 km/s. The suite of machine diagnostics included linear Rogowski coils and Faraday rotation for current measurements. The experimental diagnostics include Bdot probes, multi-channel photon Doppler velocimetry (PDV), and single-frame, flash X-radiography to evaluate the performance of the high precision liner implosion. Currently, work is focused on integrating PHELIX into normal operations with the 800 MeV proton radiography facilities. There, high-resolution, high-frame-rate imaging of hydrodynamic experiments will be possible., See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th). Held in San Francisco, CA on 16-21 June 2013., The original document contains color images.

Pulsed Power Hydrodynamics (PPH) is an application of low-impedance pulsed power, and high magnetic field technology to the study of advanced hydrodynamic problems, instabilities, turbulence, and material properties. PPH can potentially be applied to the study of the properties of warm dense matter (WDM) as well. Exploration of the properties of warm dense matter such as equation of state, viscosity, conductivity is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to slightly above solid density) and modest temperatures (1-10 eV). Conditions characteristic of WDM are difficult to obtain, and even more difficult to diagnose. One approach to producing WDM uses laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers are applying these techniques. Pulsed power hydrodynamic techniques, such as large convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through multiple shock compression and heating of normal density material between a massive, high density, energetic liner and a high density central anvil are possible ways to reach relevant conditions. Another avenue to WDM conditions is through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. In this paper we will examine the challenges to pulsed power technology and to pulsed power systems presented by the opportunity to explore this interesting region of parameter space., See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th). Held in San Francisco, CA on 16-21 June 2013., The original document contains color images.

The paper discusses devices with a Disk Explosive Magnetic flux compression Generator (DEMG), which are similar to the ALT-1,2 experimental devices and are intended for testing the possibility of producing 1-3 TPa (10-30 Mbar) pressures and the possibility of measuring Hugoniots of different materials at such pressures. It is expected that two-layer, cylindrical liners, Al+Fe and/or Al+W, will be used, driven by 4-5 MG magnetic fields to tilde 20 km/s velocities. The paper presents and discusses simulated characteristics of these devices, in which currents, energies and powers delivered to the liner load can reach tilde 70 MA, tilde 40 MJ and tilde 20 TW and exceed those in the ALT-1,2 devices by a factor of tilde 2, tilde 4 and tilde 7, respectively., See also ADM002371. Presented at the 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th), held in San Francisco, CA on 16-21 June 2013.

Pulsed Power Hydrodynamics (PPH) is a new application of low-impedance, pulsed power technology to the study of complex hydrodynamics, instabilities, turbulence, and material properties in a highly precise, controllable environment at the extremes of pressure and material velocity. The Atlas facility, designed and built by Los Alamos, is the world s first, and only, laboratory pulsed power system designed specifically to explore this relatively new family of pulsed power applications. Constructed in the year 2000 and commissioned in August 2001, Atlas is a 24-MJ high-performance capacitor bank delivering currents up to 30-Megamperes with a rise time of 5 to 6- sec. The high-precision, cylindrically imploding liner is the tool most frequently used to convert electromagnetic energy into the hydrodynamic (particle kinetic) energy needed to drive strong shocks, quasi-isentropic compression, or large volume, adiabatic compression for the experiments. At typical parameters, a 30-gr, 1-mm-thick liner with an initial radius of 5-cm, and an intermediate current of 20- MA can be accelerated to 7.5-km/sec producing megabar shocks in medium density targets. Velocities up to 20- km/sec and pressures 20-Mbar in high density targets are possible., See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th). Held in San Francisco, CA on 16-21 June 2013., The original document contains color images.

The discipline of Pulsed Power Hydrodynamics is a new application of low-impedance, pulsed power technology, developed to study implosion hydrodynamics, instabilities, turbulence, and material properties in a highly precise, controllable environment at the extremes of pressure and material velocity. The discipline of pulsed power hydrodynamics arose in response to the need for economical, high-precision data to validate sophisticated numerical models used in current numerical simulations and to motivate the development of new models for future simulations. The international capability in pulsed power technology that has evolved over several decades in response to numerous other programmatic needs played a pivotal role in the development of the new discipline by enabling demonstrations of the techniques and production of introductory data long before a dedicated facility could be conceived, planned, and built., See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. IEEE International Pulsed Power Conference (19th). Held in San Francisco, CA on 16-21 June 2013., The original document contains color images.

Electrically exploded foil fuses have been employed as high energy opening switches for several years (Ref 1,2). As stored energies evolve into the tens of megajoules and currents rise to near one hundred megamperes, small improvements in fuse performance could have significant effects on the amount of energy transferred to a load. In this paper we examine changes in the parameters of aluminum fuses that produce improved fuse performance when operated without a load. The factors of fuse thickness and fuse quench are seen to affect fuse performance as well as alteration of the fuse mass, length, and width. Those fuses that performed the best were examined and their results analyzed in both the time domain and the specific energy domain., See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976-2013, and Abstracts of the 2013 IEEE International Conference on Plasma Science. Held in San Francisco, CA on 16-21 June 2013. U.S. Government or Federal Purpose Rights License