Magnetic Implosion for Novel Strength Measurements at High Strain Rates

Recently, Lee and Preston have proposed using magnetic implosions as a new method for measuring material strength in a regime of large strains and high strain rates inaccessible to previously established techniques. By its shockless nature, this method avoids the intrinsic difficulties associated with an earlier approach using high explosives. We illustrate how the stress-strain relation for an imploding liner can be obtained by measuring the velocity and temperature history of its inner surface. We discuss the physical requirements that led us to a composite liner design applicable to different test materials, and also compare the code-simulated prediction with the measured data for the high strain-rate experiments conducted recently at LANL. Finally, we present a novel diagnostic scheme that will enable us to remove the background in the pyrometric measurement through data reduction.