Abstract
A numerical analysis method is presented for evaluating the resistivity of in-flight shaped charge jets from magnetic flux signals obtained with a magnetic flux loop, which is installed coaxially with a ring-shaped permanent magnet in the same plane. The amplitude and the ratio of the positive and negative peaks of the loop voltage are used as calibration parameters. By fitting these to numerically estimated calibration curves computed from the jet shape and velocity measured using other techniques, the jet resistivity can be uniquely derived. The resistivity derived by applying this method to a signal obtained from an experiment with a Cu jet was ρ ∼ 1.39 × 10-7 Ωm and suggested that the jet temperature was around the melting point of the Cu liner (1358 K). This temperature was confirmed by a smoothed-particle-hydrodynamics simulation that reproduced the jet shape and velocity. Since the jet shape is required to generate calibration curves, imaging measurements are essential to the present analysis.
