|Budget Amount *help
¥24,700,000 (Direct Cost: ¥19,000,000、Indirect Cost: ¥5,700,000)
Fiscal Year 2020: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2019: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2018: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2017: ¥11,570,000 (Direct Cost: ¥8,900,000、Indirect Cost: ¥2,670,000)
|Outline of Final Research Achievements
The optimized superconducting multilayer structure is a candidate technology to improve the accelerating field of superconducting particle accelerators. In the present project, we have succeeded in proof-of-concept experiments and made progress in the theory of the multilayer structure. We fabricated samples of multilayer structures by coating bulk pure-Nb substrate with a thin NbN layer separated by an insulator layer. We measured the first vortex penetration field (Bv) for samples with different NbN thicknesses and confirmed the optimum thickness. The maximum Bv is 20% higher than bulk Nb alone. Also, we calculated the superheating field (Bsh) of the multilayer structure in the diffusive limit using the BCS theory and studied the thickness dependence of Bsh. Here, Bsh corresponds to the theoretical limit of Bv. The nonlinear surface resistances of multilayer structures were also calculated using the BCS theory.