Magnetron sputtering of Superconducting Multilayer Nb3Sn Thin Film

Table 3.7 the description of the peaks of Run s50.52940.5292Nb3Snthoerycubic edge length (nm)0.52900.52880.52860.52841.0 1.2 1.4 1.6 1.8current (A)Fig.3.25 the cubic edge length versus Nb sputtering currentUsing the same method of 2.3.3.3 section, we can obtain the cubic edge length ofeach sample. According to Fig.3.25, the cubic edge length increases with the Nbsputtering current increasing, except the point of 1.4A.3.3 Deposition on Nb sampleIf we fabricate the accelerator cavity with thin film, the thin film should bedeposited on substrate, which including the Nb and copper. The advantage of the Nbsubstrate is that Nb is superconductor, which means that when the part zone of thethin film is not the superconductor, the Nb is still the superconductor which make sureof that the whole accelerator cavity is superconductor. But the disadvantage is that thethermal conductor of the Nb is poor. The advantage of the copper substrate is that thethermal conductor and the mechanical property are very good. The good thermalconductor can quickly transfer the heat produced by the microwave in the thin film,which can reduce the thermal unstable of the superconductor because that if the heatcan not transfer in time, the temperature of some zone of the thin film will increaseand higher than T c . The good mechanical property can reduce the detuning of the54