Measurements on the residual resistivity ratio (RRR) of high purity aluminium under cyclic mechanical stresses

High purity aluminium used for the stabilisation of superconducting cable achieves very low electrical resistivity at 4.2 K even at high magnetic fields. However, the resistivity is strain dependent, especially cyclic strain dependent. In aluminium stabilised superconducting magnets a strain induced increase of the resistivity can be observed after only few charging cycles of the magnet. Measurements on two types of mostly favoured aluminium purities, 4N and 4N8, are foreseen. The measuring device and the planned measuring programme are described. The purpose of this paper is to communicate first results of RRR measurements and to discuss the test equipment extension for the measurements of cyclic strain behaviour