Abstract
Shaped charge jets (SCJs) are of interest in the field of ballistics because of their excellent penetration ability. The various characteristics of an SCJ, such as density, temperature and length of the jet, are important when estimating the expected penetration depth. Therefore, these characteristics have been widely researched [1-5]. Zernow studied the density deficit associated with an in-flight jet using densitometry [1]. This prior work determined that the 15-20% density deficit of a Cu jet (as reported by Jamet [2]) includes a temperature contribution of 3.5%, an experimental error of 5% and a so-called “vacancy avalanche” contribution of 6.5%. Uhlig and Hummer measured the conductivity and temperature of in-flight Cu SCJs by employing a novel magnetic diffusion technique and five color radiometry. The resulting conductivity values indicated that the tip of the SCJ had a bulk temperature on the order of 1200 K, which is in the vicinity of the melting point of Cu (1350 K) [3]. Hertel et al. developed an analytical model for the SCJ formation process. CTH calculations utilizing their analytical model accurately predicted the thermodynamic characteristics of the SCJ [4, 5]. Huang quantified the density of an SCJ and reported the density distribution based on evaluating the x-ray absorption coefficient of a metal jet [6], and found that the density of a powder metal jet decreases toward the jet tip as the jet elongates. These prior reports indicate that observations of various jet features under high temperature conditions (close to the melting point) can be a useful means of assessing the density deficit of an SCJ.
