Isentropic compression experiments (ICE) were performed on a variety of high explosives. The samples were dynamically loaded by Sandia's Z-accelerator with a ramp compression wave of 300 ns rise time and peak stress of 100-350 kbar. Sample/window interface velocities were recorded with VISAR. Experiments were performed on LX04 to obtain the stress-strain relation using a backward integration technique. Experiments were similarly performed on LX17 and the results compared to hydrodynamics calculations that used a reactive flow equation of state. Recent experiments were also conducted on single crystal HMX with the aim of detecting the phase transition believed to occur at 270 kbar.
Isentropic compression data was collected on LX-04 explosive (85% HMX and 15% Viton by weight) at 150 C using the Sandia National Laboratories Z accelerator facility. A ramp compression wave was applied to the explosive samples mounted on aluminum panels with VISAR interferometry measuring the sample and backing window interface velocity. Heating was obtained by wrapping band heaters around a thermal mass attached to each panel and temperatures were recorded by thermocouples at several locations on the panel. This work will outline the methods used, discuss the VISAR interface velocities, and present the preliminary data obtained on heated LX-04. These results demonstrate the ability to perform experiments on preheated samples to obtain isentrope data.
This book presents a history of shock compression science, including development of experimental, material modeling, and hydrodynamics code technologies over the past six decades at Sandia National Laboratories. The book is organized into a discussion of major accomplishments by decade with over 900 references, followed by a unique collection of 45 personal recollections detailing the trials, tribulations, and successes of building a world-class organization in the field. It explains some of the challenges researchers faced and the gratification they experienced when a discovery was made. Several visionary researchers made pioneering advances that integrated these three technologies into a cohesive capability to solve complex scientific and engineering problems. What approaches worked, which ones did not, and the applications of the research are described. Notable applications include the turret explosion aboard the USS Iowa and the Shoemaker-Levy comet impact on Jupiter. The personal anecdotes and recollections make for a fascinating account of building a world-renowned capability from meager beginnings. This book will be inspiring to the expert, the non expert, and the early-career scientist. Undergraduate and graduate students in science and engineering who are contemplating different fields of study should find it especially compelling.
This book constitutes the Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, Baltimore, Maryland USA, 2005. The volume embodies the most recent research on shock compression of condensed matter and includes 363 plenary, invited, and contributed papers, all peer-reviewed. Topics include: equations of state, phase transitions, chemical reactions, warm dense matter, fracture, geophysics and planetary science, energetic materials, optical studies, and more.
A long-standing goal of the equation of state (EOS) community has been the development of a loading capability for direct measurement of material properties along an isentrope. Previous efforts on smooth bore launchers have been somewhat successful, but quite difficult to accurately reproduce, had pressure limitations, or tended to be a series of small shocks as opposed to a smoothly increasing pressure load. A technique has recently been developed on the Sandia National Laboratories Z accelerator which makes use of the high current densities and magnetic fields available to produce nearly isentropic compression of samples that are approximately 1 mm in thickness over approximately 120 ns. Velocity interferometry is used to measure the rear surface motion of these samples. The resulting time resolved velocity profiles from multiple sample thicknesses provide information about mechanical response under isentropic loading conditions and phase transition kinetics. Feasibility experiments have been performed to pressures of approximately 130 kbar in copper and 300 kbar in iron with effects of the [alpha]-{var_epsilon} phase change kinetics in iron clearly observed. Work is in progress to achieve 1--2% accuracy in P-v space along an isentrope, provide uniaxial strain, and to eliminate magnetic field and current diffusion within the sample of interest.
Accurate, ultra-high pressure isentropic equation of state (EOS) data, are required for a variety of applications and materials. Asay reported a new method to obtain these data using pulsed magnetic loading on the Sandia Z-machine. Fast rising current pulses (risetimes from 100 to 30011s) at current densities exceeding many MNcm, create continuous magnetic loading up to a few Mbar. As part of a collaborative effort between the Los Alamos and Lawrence Livermore National Laboratories we are adapting our high explosive pulsed power (HEPP) methods to obtain isentropic EOS data with the Asay technique. This year we plan to obtain isentropic EOS data for copper and tantalum at pressures up to -2 Mbar; eventually we hope to reach several tens of Mbar. We will describe the design of the HEPP systems and show out attempts to obtain EOS data to date.
This book is the first of several volumes on solids in the Shock Wave Science and Technology Reference Library. This is a unique collection, and the library as a whole sets out to comprehensively and authoritatively cover and review at research level the subject matter with all its ramifications. All the chapters are self-contained and can be read independently of each other, though they are of course thematically interrelated.
Provides an up-to-date account of innovative energetic materials and their potential applications in space propulsion and high explosives Most explosives and propellants currently use a small number of ingredients, such as TNT and nitrocellulose. In comparison to conventional materials, nano- and micro-scale energetic materials exhibit superior burning characteristics and much higher energy densities and explosive yields. Nano and Micro-scale Energetic Materials: Propellants and Explosives provides a timely overview of innovative nano-scale energetic materials (nEMs) and microscale energetic materials (μEMs) technology. Covering nEMs and μEMs ingredients as well as formulations, this comprehensive volume examines the preparation, characterization, ignition, combustion, and performance of energetic materials in various applications of propellants and explosives. Twenty-two chapters explore metal-based pyrotechnic nanocomposites, solid and hybrid rocket propulsion, solid fuels for in-space and power, the sensitivity and mechanical properties of explosives, new energetic materials, and more. Explores novel energetic materials and their potential for use in propellants and explosives Summarizes the most recent advances of leading research groups currently active in twelve countries Discusses how new environmentally friendly, high-combustion energetic materials can best be used in different applications Explains the fundamentals of energetic materials, including similarities and differences between composite propellants and explosives Nano and Micro-scale Energetic Materials: Propellants and Explosives is an important resource for materials scientists, explosives specialists, pyrotechnicians, environmental chemists, polymer chemists, physical chemists, aerospace physicians, and aerospace engineers working in both academia and industry.
