The high frequency vortex motion in Nb$_3$Sn was analyzed in this work up to 12 T. We used a dielectric loaded resonator tuned at 15 GHz to evaluate the surface impedance $Z$ of a Nb$_3$Sn bulk sample (24.8 at.\%Sn). From the field induced variation of $Z$, the high frequency vortex parameters (the pinning constant $k_p$, the depinning frequency $\nu_p$ and the flux flow resistivity $\rho_{ff}$) were obtained over a large temperature and field range; their field and temperature dependence were analyzed. Comparison with other superconducting materials shows that high frequency applications in strong magnetic fields are also feasible with Nb$_3$Sn. In the present work, we report the first measurements about the microwave response in Nb$_3$Sn in strong magnetic fields.

中文翻译：

---

Nb3Sn 中强磁场涡旋运动钉扎参数的微波测量

在这项工作中分析了 Nb$_3$Sn 中高达 12 T 的高频涡旋运动。我们使用了一个调谐在 15 GHz 的介电负载谐振器来评估 Nb$_3$Sn 块状样品（24.8在。\%Sn）。从$Z$的场致变化中，获得了大温度下的高频涡旋参数（钉扎常数$k_p$、脱钉频率$\nu_p$和通量流动电阻率$\rho_{ff}$）场范围；分析了它们的场和温度依赖性。与其他超导材料的比较表明，Nb$_3$Sn 在强磁场中的高频应用也是可行的。在目前的工作中，我们报告了关于强磁场中 Nb$_3$Sn 的微波响应的第一次测量。