Target experiments with light-ion beams at KALIF: Measurements of the dynamic strength and spallation threshold of metals at high strain rates

In target experiments performed at the KfK KALIF facility, pulsed proton beams of about 20 kJ pulse energy have been used to ablatively accelerate flyer foils of macroscopic lateral dimensions ("0.5 cm) to very high velocities (up to > 10 km/s) generating impact loadings in plane target samples. An ORVIS-type velocity spectrometer has been set up and synchronised with the ion-beam driver to investigate the dynamic response of solid target matter with high accuracy (up to 1%) and very high time resolution (up to 200 ps). In proof-of-principle experiments the KALIF-ORVIS facility has been used to measure the dynamic strength solid matter to tensile fracture up to very high strain rates of 10⁸ s⁻¹. The materials under investigation have been single and polycrystalline samples of molybdenum, aluminum, and sapphire. The experiments have verified the advantageous perspectives of high-power light-ion drivers for experimental dynamic matter research.