Nb3Sn超导电磁铁

本文报导了关于筒形Nb₃Sn磁体的研究结果。观察到磁通跳跃现象。“冻结”场的分布和历史及激发场的分布紧密相关。“冻结”场可以不是中心对称的,这进一步证明了烧结的Nb₃Sn材料是非均匀介质。我们描述了新的磁体结构,避免了磁通跳跃。除利用铁心来捕获磁通外,在激发和测量磁场的方法上均具有一定的特点。利用圆筒状Nb₃Sn作为压挤磁通的活塞,在1.5°K时,曾获得的最高场强是28.5KG。

SUPERCONDUCTING ELECTROMAGNET OF Nb3Sn

Results of study on tubular Nb₃Sn magnets are presented. Magnetic flux jumping has been observed as usual. The "frozen" field distribution is closely related to the external field distribution and previous history. The distribution need not be symmetrical with respect to the mid-plane perpendicular to the cylindrical axis, as in the case of soft superconductors. This confirms the suggestion that the sintered Nb₃Sn material is not a homogeneous medium.We describe a new magnet structure with which magnetic flux jumping can be avoided. With these magnets, besides the use of the iron core for trapping magnetic flux, there are also special features in both the excitation and the measurement of magnetic fields.Utilizing the tubular Nb₃Sn as a piston, we have obtained a highest magnetic field of 28.5kG at 1.5°K.