TEMPERATURE DEPENDENT AC LOSS MEASUREMENTS ON NbTi AND Nb3Sn SUPERCONDUCTORS BETWEEN 4.2 K AND 1.8 K E.W. Seibt et D. Tabarsi J. Phys. Colloques, 45 C1 (1984) C1-475-C1-478 DOI: 10.1051/jphyscol:1984197