The development of a low level internal friction measurement technique and its application to the beta relaxation peak in niobium.

This work is concerned with the measurement of internal friction peaks in niobium at low temperatures and low frequencies, the analysis of the data from the peaks and its theoretical interpretation. A sensitive automatic apparatus using a novel variable energy supply technique, has been constructed, together with a continuous flow cryostat, A technique for analysing internal friction data by the application of constrained optimisation methods on a digital computer is described. The beta peak occuring in niobium at about 200 K at 1 Hz, is interpreted as a possible hydrogen Schoek peak. The Arhenius plot of the known values of the beta peak parameters from the present work and all other available sources, is examined in detail, and it is concluded that the plot is either non linear or exhibits a slope change. An explanation for this anomalous behaviour is advanced