Shock Compression of Bimetallic Junctions

The response of bimetallic junctions to shock loading was investigated using a new simplified geometry in which the circuit of interest is completed by impact. Techniques for measuring the 1 millivolt level signals were developed within this geometry with the extensive use of null experiments in which both parts of the junction were of the same material. It was shown that the use of a ferromagnetic material introduces a demagnetization signal that is not well characterized, which puts measurements of thermal E.M.F.s measured in nickel under shock loading conditions in some doubt. Results of experiments involving a nickel 80% chromium 20% alloy indicate that the E.M.F.s involved are anomalously high, in agreement with previous work done elsewhere. The dependence of the thermal E.M.F.s generated on the geometry or the assumptions of one- dimensional conditions has not been completely characterized but the indication is that there is indeed some dependence.