1.3 GHz超导腔磁通排出效应研究

设计并搭建了一套高精度的磁场测量和补偿系统,并结合中国科学院高能物理研究所(IHEP)的2K超导腔垂直测试平台对1.3 GHz单加速间隙超导腔的磁通排出效应开展了实验研究:利用研制的磁场测量和补偿系统能够精密地测量超导腔赤道位置磁场,并能够将磁场补偿至小于5.0×10-8 T;并对超导腔不同表面温度梯度下的磁通排出效应进行了测量分析;对钉扎了磁场的超导腔进行了射频性能测试,研究了超导腔电阻对磁通钉扎的敏感度,以及在不同电场梯度下超导腔的表面电阻变化情况。结果表明,研制的高精度磁场测量和补偿系统能够满足超导腔磁通排出研究的需求;高的超导腔表面温度梯度有利于磁通的排出;磁通钉扎电阻的敏感度随着加速电场梯度的增加而增大,导致超导腔的性能下降。此实验研究也为后续超导腔的研制奠定了一定基础。

Magnetic flux expulsion effect of 1.3 GHz superconducting cavity

The research of magnetic flux expulsion of 1.3 GHz single-cell superconducting cavity has been carried out with a new set of high precision magnetic measuring and compensating system,combining with 2 K vertical test system of IHEP.The magnetic field at the equator of cavity can be measured with the system and compensated to less than 5.0×10-8 T.The magnetic flux expulsion effect of superconducting cavity under different surface temperature gradient is measured and analyzed.The rf performance of the cavity pinned with magnetic flux is tested,and the sensitivity of superconducting cavity resistance to magnetic flux pinning and the surface resistance of superconducting cavity under different electric field gradients are studied accordingly.The results show that the developed high precision magnetic field measuring and compensating system can meet the research needs of magnetic flux expulsion of superconducting cavity.Higher surface temperature gradient of superconducting cavity is beneficial to the magnetic flux expulsion.The sensitivity of flux pinning resistance increases with the increase of electric field.The research has also laid a foundation for the development of superconducting cavity.