HOM Coupler Design Adjustment for CW Operation of the1.3 GHz 9-Cell TESLA Type SRF Cavity

One of the key features of a modern research facility is its versatility, ability to adjust for a multitude of theapplications and user needs. A challenge for the coming European XFEL is to become a multipurpose laboratory with a broad applications spectrum. Primarily,the XFEL is a pulsed machine. Having the CW operation mode would be a worthy addition. CW operation of the 1.3 GHz 9-cell TESLA Type SRF Cavity was performedseveral times at DESY and in the other Labs successfully. One of the difficulties was a heat load of the High Order Mode (HOM) couplers described in [3], for example. To amend this, a HOM coupler design adjustment is proposed and simulated