Shock loadings on thin film manganin gauges packaged by vapor-deposited alumina

To extend the measurement range to 100 GPa, a modified manganin gauge was prepared and examined. The modifications were focused on the package materials and technique. The manganin sensing elements were first deposited by magnetron sputtering on Al2O3 substrates, and then covered by a layer of Al2O3 films several μm thick by electron beam evaporation. After being placed on slabs of Al2O3 ceramic, the gauges were shocked to 40–80 GPa with a light gas gun. The stress-time profiles showed a good plateau of about 1 μs in duration. The initial calibration resulted in a linear curve with piezoresistance coefficient of 0.0198±0.0002 GPa−1.