Power Coupler R&D
  • Introduction

The power coupler (or the so called main coupler, input coupler) is one of the most critical parts of the superconducting accelerators. It transfers power from the RF source to the superconducting RF cavity, supports high thermal gradients, provides the vacuum barrier and prevents contamination of the cavity. Covering several areas of advanced technologies the design phase is critical and the final results can be a very complicated structure. In general, power couplers are as delicate and as expensive as SRF cavities.

    The purpose of this study is to improve the design and performance of the TTF-III couplers and study new prototypes of power couplers for ILC, and in the same time to gain and develop the common technologies and experience in designing, fabricating and testing the power couplers for superconducting accelerators, which is especially important for the ongoing SRF R&D activities in China. As for the future, we would like to industrialize, fabricate and test a part of the large number of power couples for ILC and other projects in China.

  • Research Status and Plan

      The ILC group at IHEP is designing a short ILC-type cryomodule which contains a 9-cell superconducting cavity. The power coupler is being studied as one of the components. At first stage, we are making collaboration with KEK on the capacitive coupler. We have finished the 3D drawings of the capacitive coupler and are now performing the electromagnetic and thermo-mechanical simulation as well as designing the tuning mechanism of this kind of coupler for STF phase 2. We will also collaborate with LAL on the power coupler R&D.


3D Drawing of the KEK Capacitive Coupler
  • HFSS Simulation of Capacitive Power Coupler
We have performed HFSS simulation of the capacitive coupler, especially the change of S11 due to the antenna movement ( in order to fulfill variable coupling).
Mesh of the HFSS Model for the Capacitive Coupler

S11 Change due to Antenna Movement


J.Y.Zhai, IHEP