Outstanding high gradient performances of two test structures produced at PSI for the CLIC project

X-band (12 GHz) radio-frequency (RF) accelerating structures are under consideration for future free electron lasers, medical linacs and linear colliders. Two such structures, built by PSI in the framework of a CERN/PSI collaboration, are currently being tested at high power at CERN. They are reported to have reached an accelerating gradient in excess of 115 MV/m (CERN Courier, April 2018, http://cerncourier.com/cws/article/cern/71293(link is external)), making them among the best X-band structures to have been tested by the CERN Linear Collider project group. The structures have benefitted from the fabrication protocols used for the SwissFEL C-band structures. The gradient continues to improve with further “conditioning” at CERN. For structure “aficionados” a recent conditioning curve (courtesy of CERN) shows structure T24PSI1 approaching 120 MV/m. The structures were financed by an SNF FLARE* grant 20FL20_147463.
* Funding for LArge international REsearch projects.