Nb3Snテープ線材の引張強度と超電導特性
1978 年 13 巻 3 号 p. 148-153
詳細
1978 年 13 巻 3 号 p. 148-153
We have made experiments to decide the optimum winding tension in constructing high field magnets, using N3Sn tape of I. G. C. as material.
The samples have been stressed uniaxially at room temperature and measured at liquid He temperature.
When those tapes are cooled down to liquid He temperature there the thermal stress (or strain) are derived from the difference of the thermal expansion of components materials (Nb, Nb3Sn, Solder, Cu) Nb3Sn layer is under compressional stress for this effect and experimences degradation of Tc.
The degradation coefficient of Tc (∂Tc/∂p) was found to be -0.16×10-3K/Atm.
The degradation of Ic on the tensile stress are observed even in elastic region and it is conjectured that the region of this effect is exsistence of the solder layers and the lower elastic limit of Cu layers compared with that.
Guided by the above obtained results we have manufactured a magnet with the low winding tension (-60kg/cm2) and have already achived field of 11.7T.
