多功能腔集真空泵安装、束流过渡漂移、束流在线测量及方便机器检修等诸多功能于一体,是"神龙一号"加速器束流传输系统的一个关键部件.简要介绍了多功能腔设计中的磁轴准直、输运磁场的连续性以及横向阻抗几个关键问题,阐明了多功能腔的可维修特性和磁轴准直性能,分析了多功能腔对输运磁场连续性的影响,计算了多功能腔的低横向耦合阻抗,并提出了降低横向耦合阻抗的措施.多功能腔的应用简化了束流传输线的结构,提高了束流传输线的性能,将在"神龙一号"直线感应加速器的调试中起到非常重要的作用.

Multifunctional cavity(MFC) is one of the most important parts of beam transport system in the "Dragon-Ⅰ" LIA. An MFC assembles the flange for vacuum pumps,the drifting tube for electron beam and the BPM for beam diagnostics on line together. Moreover,MFC is convenient to the machine repairing. In this paper,the key points of the MFC design are presentedthe alignment and repairability are clarified,the continuity of magnetic field is analyzed,the transverse impedance is simulated,and the methods to lower its transverse impedance are presented. The application of MFC has not only simplified the structure of beam transport line,but also improved its performances.